190 these results suggest diminishing steric fit of serotonin to these antigens. Additional evidence that the antigenic determinant on B.P. is not quite the same as on E.F. is given by our results in rhesus monkeys injected with encephalitogenic mixture and by older fluorescence studies.5 It is, of course, conceivable that " liver antigens " might also contain some determinants which are shared with E.F. The low level of positive results in the control sample, to which Dr. Weir points, is in fact a statistically significant one because of the small scatter of the readings, and Dr. Weir has anticipated the burden of a paper in preparation relating to the question of horror autotoxicus. Widespread autoimmunisation, usually of minor degree, is well documented among normal people 6,7 and the important question is why it does not progress. The role of bacterial adjuvants " in promoting immunisation has long been recognised 8-12 and is certainly worth reinvestigation, especially by the method we described which appears so sensitive. Meanwhile we would again emphasise the need for caution in interpreting and assessing our results, and urge once more the need for independent confirmation. We ourselves are undertaking a more extensive investigation, not only of patients with malignant tumour, but also of autoimmune conditions " and of the normal population with special reference to the ageing process.6 Our original normal group covered a wide age-range embracing the malignant group. "
M.R.C. Demyelinating Diseases Unit, Newcastle General Hospital, Newcastle upon Tyne NE4 6BE.
E. J. FIELD E. A. CASPARY.
burgh cesophageal-cancer series differ from expectation. Department of Medicine, M. J. S. LANGMAN General Hospital, J. B. MACDONALD. Nottingham. CLINICAL BIOCHEMISTRY IN THE HOSPITAL LABORATORY SERVICES SiR,—I am writing to support the letter from Dr. James and his colleagues (Jan. 16, p. 142) in relation to the changes suggested by Dr. Goldberg and Dr. Mitchell.One of the major problems in regard to these changes is the effect that they would have in making clinical biochemistry just a laboratory service to medicine, run by non-medical scientists or by doctors who had entered the laboratory as a retreat from the patient. There is, and always will be, a place for the medically qualified clinical biochemist who is not afraid to give advice at the bedside and is, in fact, capable of handling patients in the same way as other clinical colleagues who practise a specialty. The situation in regard to the heematologist springs to mind. This matter is of the highest importance, and I sincerely hope that those who advise the Department of Health and Social Security are not entirely non-medical scientists and medical graduates who have retreated from the patient. For reasons arising largely from what apparently happens in certain teaching hospitals, the patient-oriented clinical biochemist tends to seek an appointment in non-teaching
I deprecate the growing habit of referring the medical graduate in this specialty as a chemical pathologist and the non-medical graduate as a clinical biochemist. In so far as they are made up of protein, fat, carbohydrate, and the like, all pathologists are chemical. The specialty is really the application of biochemistry to the clinical situation and is best called " clinical biochemistry ". It still remains, however, a branch of clinical pathology, although its service aspects can be practised by non-medical graduates. Department of Clinical Biochemistry, Royal Victoria Infirmary, A. L. LATNER. Newcastle upon Tyne NE1 7RU. to
ŒSOPHAGEAL CANCER AFTER GASTRIC SURGERY SiR,-We accept the view of Dr. Shearman and Dr. Arnott (Jan. 16, p. 135) that retrospective examination of case-notes tends to be a less accurate experimental method than a planned prospective investigation, but we think it unlikely that inaccuracies due to retrospective analysis would have selectively affected the recording of previous
gastric surgery in our oesophageal-cancer patients as compared with the rectal-cancer controls. If anything, one might expect under-recording in patients presenting with symptoms of lower bowel-disease rather than in those with problems related to the upper digestive tract. Dr. Shearman and Dr. Arnott also suggest that it would have been desirable to conduct the investigation in a static population, presumably because all records would be more easily obtainable. We confirm that in Nottingham there are only two district general hospitals and one radiotherapy centre, and that the population does not seem to have a high mobility. They add that they and their colleagues have now found a total of 11 out of 178 patients with squamous oesophageal cancer who have had previous gastric surgery. However, this total includes 8 (8-7°0) in the 92 already reported and only 3 (3’5°o) in the second group of 86. There is much epidemiological evidence to suggest that peptic ulcer is a particular clinical problem in Scotland,13,14 and controlled comparisons are therefore clearly needed to show that the observed gastric-surgery figures in the Edin4. 5. 6. 7.
Caspary, E. A., Field, E. J. Europ. Neurol. (in the press). Field, E. J., Ridley, A. R., Caspary, E. A. Br. J. exp. Path. 1963, 44, 631. Burnet, F. M. Self and Not Self; p. 9. Cambridge, 1969. Walford, R. L. The Immunologic Theory of Ageing. Copenhagen, 1969.
8. 9. 10. 11. 12. 13. 14.
Burky, E. L. J. Allergy, 1934, 5, 466. Cavelti, P. A., Cavelti, E. S. Archs Path. 1945, 39, Cavelti, P. A., Cavelti, E. S. ibid. 1945, 40, 158. Cavelti, P. A., Cavelti, E. S. ibid. p. 163. Cavelti, P. A. J. Allergy, 1955, 26, 95. Weir, R. D., Backett, E. M. Gut, 1968, 9, 75. Jamieson, R. A. Br. med. J. 1955, ii, 222.
SiR,—In your note on development of vaccines and vaccination procedures (Jan. 16, p. 147) it is not made clear that the vaccines developed against shigellosis are live attenuated variants given orally: these variant strains may be derived in different ways and are protective against the specific infecting Shigella type, usually one of the Flexner serotypes, although there is hope that a live attenuated vaccine may be developed against the highly virulent shiga infection which has lately been spreading through Central America and has reinvaded the U.S.A. In the third paragraph you discuss the use of combinations of vaccines, given subcutaneously. The administration of different live vaccines at the same time usually requires separate injections, some given subcutaneously as with measles and yellow-fever vaccines, others intracutaneously as with smallpox and B.c.G. vaccines, but not mixed together in a single subcutaneous dose. Although the simultaneous injection of several different vaccines may elicit satisfactory antibody responses to each of them, it is questionable whether it is good policy to give measles, mumps, rubella, and smallpox vaccines simultaneously to infants. Perhaps more attention might have been given, at the Washington conference, to the great difficulties in the implementation of vaccination procedures in developing countries. Edinburgh. Goldberg,
ROBERT CRUICKSHANK. I.
J. L., Mitchell, F. L. Lancet, 1970, ii, 1240.