1004

average cost about E13. At a number of hospitals 80% ormore of the patients were given appointment times duringthe first hour of the morning or the first hour of the after-noon session, in order to ensure that they arrived in goodtime and to allow for any X-ray examination that might benecessary. No ambulance service can cope efficiently andeconomically with such a concentrated demand, and thesystem defeated its own object. Some patients arrived late,many were kept waiting, and those who came to hospitalby public transport had to contend with the morning rushhour. A wider spread of appointments would avoid latearrivals and long waiting.A sitting-case ambulance will hold about a dozen

patients; but if it tries to work near to capacity and collectpatients from a long round, waiting time and late arrivalwill increase. The hospital car service might be used moreoften to pick up outlying patients: some local healthauthorities depend entirely or very largely on this volunteerservice for sitting cases; and these authorities are not thosewith the highest transport bills. The hospital car is morelikely to get the patient to hospital on time and to get himhome without waiting too long. Moreover, its cost is 9d.per vehicle-mile, compared with ls. 9d. to 2s. 6d. forambulances.

The report sets out the cost per person carried for each

county and county borough in England and Wales, andthe variations are very wide indeed (from Bath at 32s. 8d.to Southend at 8s. lld.). There is ample justification forlooking further at the efficiency of the service both athospitals and at ambulance stations. The new report andits practical suggestions are a useful starting-point.

RETROPERITONEAL LYMPHOGRAPHY

As a method of demonstrating retroperitoneal metas-tases, lymphography has not been widely accepted. Thewater-soluble contrast medium used in the originaltechnique 1 may have been responsible for some of themisleading results. Latterly, however, the introductionof an oily contrast medium has revived interest in thistype of examination. 6-8 ml. of iodised oil (’ Lipiodol ’)is injected through a fine needle or a no. 10 polyethylenecatheter into one of the lymphatics in the dorsum of thefoot over a period of about two hours, either by gravityor by a special injection syringe driven by a small electricmotor. A previous injection of methylene-blue into theweb between the lst and 2nd toes stains the lymphatics,and thus identifies them. The amount injected in tenminutes should not exceed 0-5-0-75 ml. and the lym-phatics should not be ruptured. After about two hours,the dye will have spread to the middle lumbar nodes, andthe interconnecting lymphatic pathways in the leg andthe retroperitoneal spaces will be well seen. Furtherfilms after twenty-four hours usually outline all the

major lymph-nodes. A dose of 0-6 ml. per kilogrammebody-weight of ultra-fluid lipiodol injected into a rab-bit’s lymphatics frequently caused death,2 and a dose ofnot more than 0-2 ml. per kilogramme has been sug-gested for young patients. Ordinarily the examinationis well tolerated, and a sedative is required only in thenervous subject.

Enlargement and alteration in the internal archi-tecture of the lymph-glands and disturbances of the

interconnecting lymphatics can be demonstrated by1. Kinmonth, J. B., Taylor, G. W., Harper, R. A. K. Brit. med. J. 1955,

i, 940.2. Gough, M. H., Guiney, E. J., Kinmonth, J. B. ibid. 1963, i, 1181.

means of this method of lymphography. Gland enlarge-ment is greatest in the lymphomatous tumour.3 3 In

lymphosarcoma, including reticulum-cell sarcoma, the

enlarged nodes show a lacy or coarsely reticulated pat-tern. In Hodgkin’s disease, rounded or irregular fillingdefects are seen which do not usually encroach on theperiphery of the node. In contrast, secondary depositsfrom carcinoma cause filling defects which are often

marginal, and the part of the gland not invaded bytumour is usually normal. In carcinoma, although thelymph-nodes are enlarged, the enlargement is seldom asgreat as in the other groups. Inflamed lymph-nodes are asa rule not strikingly increased in size, although numeroussmall filling defects, mainly central, may be noted.

Lymphography has proved least helpful in tumours ofthe cervix and uterus, because the immediate glands are notoutlined by dye injected into the foot. The demonstrationof metastases in the lumbar region seldom influences thestaging of this disease; hence routine lymphangiographyin carcinoma of the cervix is probably not worth while.In such cases internal-iliac venography possibly offersthe best chance of demonstrating metastatic nodes. On theother hand, lymphography has been shown to be much morereliable than pelvic venography or cavography in thedemonstration of retroperitoneal metastases.4 If the doseof lipiodol is maintained at 6-8 ml. and the injection isstopped as soon as the -lower lumbar nodes are well filled,oil embolism in the lung is uncommon. But with largerdoses an appreciable quantity of the lipiodol may enterthe pulmonary circulation through the thoracic duct,and will be visible in radiographs of the chest. In patientswith pre-existing lung disease, oil embolism has proveddangerous, and lymphography is best avoided in suchcases.5

Many patients have a low-grade febrile reaction abouttwenty-four hours after the examination, but this doesnot seem to give rise to much trouble. When there hasbeen previous radiotherapy, or when extensive metas-tases are suspected, it is as well to follow the course ofthe examination, by means of either spot films or animage-intensifier, lest an early lymphovenous fistulahas been established or the dye has extended to theupper abdominal and thoracic nodes through collateralchannels.

NOBEL PRIZE FOR CHEMISTRY

THE achievements for which Prof. Dorothy CrowfootHodgkin, of Oxford, was last week awarded the NobelPrize for Chemistry include the elucidation of the struc-ture of vitamin B12 by X-ray crystallography. This featof molecular detection was a combination of crystallo-graphy at Oxford, calculation by computer in Los Angeles,and chemical investigations at Cambridge and the GlaxoLaboratories at Greenford. It was the culmination ofeight years’ imaginative application of the techniques ofX-ray crystallography. These were the methods whichDr. Hodgkin had earlier used, with Prof. J. D. Bernal atCambridge, to demonstrate that proteins had preciselyorganised molecules; and later the structure of penicillinwas also displayed by X-ray analysis. Dr. Hodgkin is atpresent in Ghana, where her husband, Mr. ThomasHodgkin, is director of the Institute of African Studies inthe University of Ghana.3. Dolan, P. A. Brit. J. Radiol. 1964, 37, 405.4. Mahaffey, R. G. ibid. p. 422.5. Bron, K., Baum, S., Abrams, H. L. Radiology, 1963, 80, 194.6. Hodgkin, D. C., Pickworth, J., Roberston, J. H., Trueblood, K. N.,

Prosen, R. J. Nature, Lond. 1955, 176, 325.