1106 The two samples of lactoferrin (Dr Masson and Dr Baudner) were immunologically identical on testing by doublediffusion technique, and the precipitating lines between each immune serum and each lactoferrin fused completely. The immunoplates contained twelve wells. Three were filled with 2 x 20 A of standard lactoferrin diluted 1/2 (20 g/ml), 1/4, and 1/6. The other wells contained 2 x 20 .1 of the different pancreatic juices, concentrated by lyophilisation or alcoholic precipitation. The protein content (measured by optical density at 280 nm with an extinction coefficient of Efïfi 20) ranged from 9 to 47 mg/ml juice. The plates were allowed to diffuse 48 h at 20 °C and then washed with isotonic saline for 3 days. The plates were stained for 1 min in 0-1% amidoschwarz (Merck) and then destained in 10% acetic acid. A standard curve was constructed by plotting the square of the diameter of the rings of precipitation against the lactoferrin concentration, and lactoferrin concentrations of samples of pancreatic juice were read off from this standard curve. By this method it is possible to visualise a lactoferrin concentration of about 2 Lg/ml to 25 fLg/ml. These results are shown in the figure, expressed as a percentage of total protein. The data obtained by radial immunodiffusion and those given by radioimmunoassay were in good agreement. The two assays confirm the increased lactoferrin concentration in juice from men with chronic pancreatitis. In six normal juices the range is from 0.002 to 0-02% with a mean of 0.013%, and in six juices from men with chronic calcifying pancreatitis from 0.033 to 0.92% with a mean of 0-23%. The assay of lactoferrin on immunoplates may be as accurate as radioimmunoassay, and can be easily set up in the

The crucial question is-how do the minor hazards of interrupting whole-body irradiation compare with anaesthetic complications in a patient who will often already have received considerable cytotoxic chemotherapy? Cape Town Leukæmia Centre and Departments of Hæmatology and Radiotherapy,

PETER JACOBS HELEN S. KING

Groote Schuur Hospital, Observatory, Cape Town, South Africa

=

laboratory. Unité de Recherches de

Pathologie Digestive

(INSERM U31),

C. FIGARELLA

TRIMETHYLAMINE METABOLISM IN LIVER DISEASE

SiR,—Trimethylamine (T.M.A.), a highly volatile amine, is responsible for the odour of rotting cartilaginous marine fish. The major source of T.M.A. in man is the metabolism of dietary choline by intestinal bacteria. T.M.A. formed in this way is normally absorbed into the splanchnic venous system and is converted to the stable non-volatile T.M.A.-N-oxide by the hepatic enzyme amine oxidase.2.3 Any T.M.A. not oxidised enters the systemic circulation where it is excreted in urine, breath, and sweat, normally in minute quantities. Interference with the hepatic metabolism of T.M.A. could be expected in patients with cirrhosis of the liver, because of impaired hepatocellular function or because of the presence of portasystemic venous shunts. This would result in increased levels of T.M.A. entering the systemic vascular system to be excreted in increased amounts in both breath and urine. In a pilot study to investigate this possibility, urinary trimethylamine excretion was measured in patients with liver disease.

J. P. ESTEVENON

46 chemin de la Gaye, 13009 Marseille, France

H. SARLES

1. Gruger, E. H. J. agric. Food Chem. 1972, 20, 781. 2. Lintzel, W. Biochem. Z. 1934, 273, 244. 3. de la Huerga, J., Popper, H. J. clin. Invest. 1951, 30,

GENERAL ANÆSTHESIA FOR HIGH-DOSE TOTAL-BODY IRRADIATION

SIR,-Dr Whitwam and his colleagues (Jan. 21,

p. 128) deof general anaesthesia for patients undergoing whole-body irradiation. In the light of our experience with this form of radiotherapy we are concerned that our British colleagues should have found it necessary to resort to general anaesthesia. In our bone-marrow transplantation programme the patients with refractory or relapsed acute leukaemia are irradiated over a 2 h period from alternate sides of the body to a dose of 1000 rad determined in the midplane at the level of the pelvis, and special attention is given to protection of the ,hands from undue exposure. We can appreciate that there are benefits of general anaesthesia in this setting, but do not think that it is routinely necessary. We find premedication with metoclopramide for 48 h before irradiation and chlorpromazine immediately before exposure is remarkably effective. We cannot claim that our patients do not become nauseous, but we have never had to discontinue irradiation for this reason, although further anti-emetics may occasionally be required after the first hour; we have certainly not encountered the situation where therapy needed to be interrupted twenty times. On the day of radiotherapy the patients receive diphenoxylate and codeine phosphate as prophylaxis against the diarrhoea that may follow from radiation sickness. The doses are adjusted to meet individual requirements. Our greater concern, however, is the effect that anaesthetic agents may have on the liver; for example, cytotoxic drugs are hepatotoxic’ and, particularly when combined with radiation (unpublished) may result in hepatitis.

scribe the

1.

use

Penta, J. S., 247.

von

Hoff, D. D., Muggia,

F. M. Ann.

intern.

Med.

1977, 87,

T.M.A. responses to choline

463.