B O O K R E V I E W S

E s s e n t i a l s o f S u r g e r y fo r D e n t a l S t u d e n t s . By J. COSBIE Ross , M.B . , C h . M . ,

F .R .C .S . Second Edi t ion . Pp. 286, wi th 2o 7 i l lustrat ions. ( E d i n b u r g h and

L o n d o n : E. & S. L iv ings tone Ltd . 1952.) 27s. 6d.

This is a useful book. It will, however, prove inadequate for the dental schools which insist on a wider picture of surgery. For example, the chapter dealing with fractures is limited to the jaw and face bones, and apart from tongue and buccal cavity there is no mention of the alimentary tract. The subject matter, including especially the surgical aspects of the head and neck, is very well described and clearly illustrated, and should prove of value to dental students. There is a useful chapter on radium and X-ray therapy.

A. B. W.

Br i t i sh M e d i c a l B u l l e t i n , Vol. 8, Nos . 2-3, 1952. Pp . I I I - 2 5 5 . Par t I. Isotopes in

Med ic ine . (Medica l D e p a r t m e n t , T h e Bri t ish Counci l . ) ISS.

This symposium has been prepared to give medical readers a general picture of the kind of investigations which are being carried out with radioactive isotopes at the present time in Great Britain. The papers are arranged according to subject matter and fall roughly into six groups, starting with the general principles of assay and standardisation, the design and operation of apparatus for the detection and measurement of the activity of a sample, and a description of the visual techniques for locating radioactive material in a specimen. From the information given in this section it should be possible for a newcomer in the isotope field to choose from the wide variety of radiation detection methods the one best suited to his particular problem.

The second group deals with thyroid metabolism problems and the treatment of thyroid disorders with radioactive iodine t31I. The selection of cases, the choice of suitable doses, and the possibility of malignant changes and other adverse effects are discussed. Case histories are given for several patients with thyrotoxicosis or thyroid cancer.

For intracavitary irradiation of the bladder a new method has been tried, that of introducing a latex bag into the bladder and inflating with a measured volume of solution containing either ~tNa or S2Br, both of which are short-lived isotopes of physiologically harmless elements.

As a palliative treatment of malignant pleural and peritoneal effusions, colloidal lgSAu has been used with some success. The last paper in the third group is a report of the attempted localisation of brain tumours with tatl-diiodofluorescein and a scintillation counter.

The clinical research methods reported in the fourth group are possibly of more interest to the plastic surgeon than those in the other groups as they deal with the measurement of red-cell and blood volumes, blood circulation rates, and tissue clearance of inorganic ions. Red cells can be labelled with ~2p in vitro by an exchange process taking place between the inactive phosphate (3tp) ions already in the cells and the added radioactive phosphate ions. The loosely bound phosphorus is not lost readily from the cells in the blood-stream at body temperature, so sufficient time can be allowed after injection of the labelled blood for complete mixing with the total blood volume before sampling and counting.

The problem of hmmodynamics can be approached in several ways. In human subjects the direct measurement of blood flow between two defined points is possible by injecting a small volume of radioactive sodium chloride solution at one point and observing the arrival of the active solution with a counter placed over the second point. Since =*Na emits a penetrating gamma ray it is easily detected through skirt and tissues and a very small quantity of the active salt is required. It is convenient to use 2*Na since it has a short half life, is not selectively absorbed by any tissue in the body, and, being a normal constituent of blood and tissue, does not produce a reaction on injection. In experimental animals a~P labelled blood can be injected at one point and samples withdrawn at suitable time intervals at the second point.

The study of the peripheral circulation by measuring the " build-up " of radioactive material at a site remote from that of injection has been undertaken, but in this country it has not proved satisfactory. The reverse of the " build-up " method, that of measuring the rate of removal of radioactive material from an injection site, is now used by several units. Many factors have been shown to influence the clearance rate of 2*Na from the injection site, and investigations must be carried out under strictly controlled conditions of rests environmental and skin temperature, and depth and site of injection.

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216 BRITIStl JOURNAL OF PLASTIC SURGERY

The most promising application of the method is the study of the local circulation in regions of skin and tissue, and this may therefore become a useful research tool for studying the problems arising in plastic surgery. In the case of tubed skin pedicles the clearance rate does not appear to be affected by the environmental conditions, and with care in checking possible sources of experi- mental error reasonably consistent experimental results have been obtained and a programme of clinical studies has been carried out with automatic equipment designed to reduce the tedious work involved in recording large numbers of observations.

The results of clinical studies which relate directly to the practical aspects of plastic surgery are summarised. The circulation rates in first, second, and third stage pedicles have been measured, and as a result of experience already gained it is apparent that a considerable saving of time can be achieved by the application of the experimental results obtained with ~*Na clearance measurements, and it is reported that some operations can now be completed in a few weeks instead of months. In cases where an inadequate circulation was demonstrated, it could be accounted for by some abnormal condition, which could usually be corrected before any permanent damage had been suffered by the pedicle. Studies are proceeding to provide data on problems relating to the post-operative care of pedicles and flaps, and various clinical tests are being compared with the sodium clearance measurements.

Biochemical investigations are reported in the fifth group, and these cover a wide range of materials and isotopes. Experiments with penicillin labelled with I~C and with 3;S, and with vitamin Bxz labelled with ~~ a~Pj and ~C are in hand to study the site and mode of action of these substances of intense biological activity. Recent work with carbon isotopes confirms that the carbon dioxide of a tissue is in a dynamic state and is continually exchanging with the carbon dioxide of other tissue and the body fluids.

In the study of protein metabolism, plasma protein metabolism, and fat synthesis~ stable and radioactive isotopes have been used, but as several ~C-labelled compounds are now available in this country with high specific activities the bulk of the work has been done with this isotope. Multiple tracing techniques using more than one label have been used in immunochemistry to make sure that the label is not transferred from one compound to another, and so far studies have been confined to proteins labelled with ~3~I, a.,p, and ~S. Stable tr'N has been used in chemical pathology in studies in porphyria, and up to the present almost all isotope work has been carried out on cases of congenital porphyria.

The symposium closes with three articles of particular interest to anyone who wishes to start work with radioactive isotopes. The problems associated with the production of labelled compounds, particularly those containing ~C, on a commercial scale are considered, and some indication of the cost involved in producing compounds to meet special requirements is given.

The precautions recommended for handling radioactive materials are set out to meet the needs of users in the different fields, the conditions which exist at the tracer and research levels being separated from those at the high-activity, therapeutic level. The nature of the hazards, the maximum permissible doses and contamination levels, and suggested disposal of waste are given in convenient paragraphs for reference. Representative types of monitoring and handling equipment are illustrated and their limitations pointed out.

Finally, some details are given of the production and supply of the medically important radioisotopes, including their relevant physical properties and the chemical forms usually available.

A. N. B.

L e T r a i t e m e n t C h i r u r g i c a l d e la D i v i s i o n V61o-pala t ine C o n g ~ n i t a l e . By D o c t eu r

P IER~ DUMAS. Pp . 86, wi th 5 i l lustrat ions. (Paris : Librai r ie A m e t t e . 1952.)

This is an account by a member of the Clinique d'Orthop~die et de Chirurgie Infantile of the treatment of cleft palates in the Clinic at Lyon for the last twenty years. The author reports the result of 209 operations by Professor Guilleminet. He describes ho~- the technique which was originally based on Veau has been steadily modified in succeeding years, and demonstrates improved results in the patients treated. Unfortunately only 6o per cent. of the patients have been followed up, so that there is a limited amount of clinical material available for estimating speech.

Briefly the modifications in technique are that hammular process fracture is now carried out in every patient, that metal has been abandoned in the " suture musculaire," and that bipedicle flaps are employed whenever possible instead of the Veau type of flap. The ideal age of operation is considered to be between fifteen and twenty months. Extensive employment of up-to-date chemotherapy contrasts strongly with old-fashioned an,~sthesia in which chloroform is preferred to ether. It is surprising that there is only one fatality in 2o9 patients, a case of death by hyperthermia pallida.

With regard to speech training, the author agrees that the parents are the best trainers in the early years, but a qualified speech therapist is employed if there are faults in speech after 4 or 5 years of age. The role of the orthodontist is appreciated but not enlarged upon.