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NEW ANTI-HYPERTENSIVE AGENTS ?

AMONG the side-effects from administration of dimer-

caprol (BAL) is an increase of blood-pressure. This issometimes quite striking ; Sulzbergen et al.,1 for example,described rises of up to 220/140 mm. Hg in normalsubjects. It comes as a surprise therefore to find dimer-caprol, together with some of its close chemical relatives,put forward as an anti-hypertensive agent. Yet Schroeder 2claims that in a moderate dose it caused a lowering ofblood-pressure lasting several hours in hypertensivepatients.

Schroeder’s brief report is mainly concerned with

experimental findings. Rats were made hypertensive bypartial constriction of one renal artery ; and the testsubstances were injected intravenously into anaesthetisedanimals, both normal and hypertensive. It was foundthat substances with a sulphhydryl group at the end ofa chain of two or three carbon atoms lowered the blood-pressure in hypertensive, but not in normal, animals.Dimercaprol, which is 2, 3-dimercaptopropanol, is onesuch substance ; cysteine (but not cystine) is another.The same substances inhibited to some extent the actionof a number of pressor agents.The clinical worker has learnt to be sceptical about

the significance of the many pressor and anti-pressorsubstances whose action has been demonstrated experi-mentally. It is not difficult to lower for a time the

blood-pressure of a hypertensive subject; nor indeed is itrare for a drug to produce. a much more conspicuousreduction of a high than of a normal pressure. Never-theless, an actual reversal of effect is much more striking,and suggests an action more specific than that of mosthypotensive agents. One is reminded of the action ofbenzodioxane, which lowers the pressure in patientswith phaeochromocytoma but raises it in others. Manywill therefore want to repeat Schroeder’s experimentswith dimercaprol in hypertensive subjects. It is unlikelythat this substance could itself be of value in the treat-ment of hypertension, since its side-effects are numerousand unpleasant, but a trial of some related substanceswould clearly be of interest. Even if the hope of usefultherapeutic effect proves illusory, there will remain a

challenging clue to the baffling problem of hypertension.SURGEONS IN HONOLULU

THE organisation of the Pan-Pacific Surgical Congress,held in Honolulu from Nov. 11 to 17, was a model ofefficiency. The association was founded in 1928 to enable

surgeons in countries bordering on the Pacific Ocean toexchange ideas and methods, and with the hope thattheir acquaintanceship would help to develop goodfellowship between these countries. Hitherto the associa-tion has been unlucky, in that every meeting hascoincided with some major national or internationaldisaster. However, it was a sturdy child and hasweathered the storms successfully. Registrations for the1951 congress numbered 537, representing 14 countriesbordering on the Pacific. But for the financial restrictionsthat still embarrass the sterling block the attendance wouldcertainly have been larger still. With this meeting theassociation has surely thrown off its jinx. It was notablenot only for the world-renowned Hawaiian hospitalitybut also for the able planning of the scientific sessions.Among the best of these were the daily breakfast meetingswhere a variety of surgical topics were discussed overeggs and bacon and a cup of coffee. Among the breakfasttopics were ulcerative colitis, discussed by Dr. J. A.Bargen ; surgery of the biliary tract, by Dr. I. S. Ravdin ;surgery of the neck and breast, by Dr. Stuart Harrington ;and paediatric surgery, by Dr. Henry Swan. The moreformal papers ranged from carcinoma of the oesophagus1. Sulzbergen, M. B., Baer, R. L., Kanof, A. J. clin. Invest. 1946,

25, 474.2. Schroeder, H. A. Science, 1951, 114, 441.

to intestinal obstruction, cirrhosis of the liver, and

chemotherapy. Separate sessions were held every dayfor those whose main interest lay in gastro-intestinal,orthopaedic, urological, cardiovascular, ophthalmological,and gynaecological disease. At the last -session planswere announced for establishing the Pan-Pacific SurgicalAssociation on a firmer basis, with definite membershiprights and responsibilities. Dr. Nils Pharsen was elected

honorary president in recognition of his past services:Dr. F. J. Pinkerton became the first director-general ofthe board of trustees ; and Dr. 1. S. Ravdin was appointedpresident for the ensuing three years. When they leftthe islands the visitors felt that many older foundationscould profit by the example of this meeting-even if theycould not transport themselves to such surroundings.Aloha

ELECTROSTATIC PHOTOGRAPHY

AN original method of photography, reported fromAmerica,l is said to have the advantage of beinginsensitive to electro-magnetic radiations with wave.

lengths shorter than light, such as X rays. Selenium.coated plates, comparable to an ordinary photo-electriccell, are given an electrical charge in the camera. Whenlight reaches the charged plate, after passing throughthe lens and shutter in the normal way, it dischargesthe surface locally in proportion to the intensity ofillumination. The exposed plate, still in the camera,is now powdered with fine charcoal, which is attractedby the remaining electrostatic charge, so that the mostcharcoal sticks where the least light has fallen. Inthis way a positive image is

"

developed " which can be" printed " by pressing the plate on sticky paper coatedwith rubber solution, or can be copied photographically.The photographic speed of this process-i.e., the

exposure required-is about the same as that of modernmedium-speed film emulsions. If the plates are whollyinsensitive to X-radiation they have some interestingpotential uses in clinical and other research. Thebrief press report does not mention their sensitivity toneutrons or other high-energy nuclear particles, but it isobviously a valuable advance if photographic records canbe made in the presence of high-energy radiations thatfog ordinary silver emulsions. The selenium plates willbe costly, but by discharging and cleaning their surfacebefore putting them back in the camera, they can be usedover and over again.

LISTS OF MICRO-ORGANISMS

MUSEUM catalogues, unless lavishly illustrated, are

seldom interesting to the general reader but provide afund of useful information for the specialist; so it iswith the directories and lists of culture collections thatare being produced by the Commonwelath Collectionsof Micro-organisms. This organisation was set up onthe recommendation of a conference convened in 1947 ;a permanent committee in London coordinates thework of national committees in the different countriesof the Commonwealth, and the first fruits are now

appearing.The Canadian committee was first in the field with its

directory of culture collections and list of species main-tained ; this has been followed by similar directories andlists dealing with New Zealand,2 and the United Kingdomand Crown Colonies. These publications were preparedfrom replies to questionaries sent out by the national com-mittees, and for this reason are probably not as completeas they might be. In the directory sections are thenames and addresses of laboratories willing to distribute

1. New York Times. Int. Ed. Suppl. March 4, p. 7.2. See Lancet, 1947, ii, 846.3. Directory of Collections and List of Species maintained in New

Zealand. H.M. Stationery Office, code no. 88-1307.4. Directory of Collections and List of Species maintained in the

United Kingdom and Crown Colonies. H.M. Stationery Office.code no. 88-1308.