255 the possibility of developing an effective means for suppressing the immune response in vivo may be increased.

synthetic,

Courtauld Institute of Biochemistry, Middlesex Hospital Medical School, London W1P 5PR

A. D. SMITH W. M. TSANG C. WEYMAN J. BELIN

VASOACTIVE INTESTINAL POLYPEPTIDE

SIR,—Dr Larsson (July 17, p. 149) has confirmed the findings of neural vasoactive intestinal polypeptide (v.i.p.) by our

group’

ference does exist, it seems, contrary to Godfrey’s finding, that the disease is more common in areas where parasitic infestations are rampant, and where ascariasis may reach a prevalence of 90-100% of all children. Furthermore, a common occurrence was the coexistence of both conditions in the same

patient. While we do not believe that a causal connection exists between parasitosis and asthma, there is also clearly no protective effect of the parasitosis either. If any relation does exist between the two conditions, it is a direct rather than an inverse one.

Nassr Pædiatric Hospital, Gaza (via Israel)

v.i.p.

is

v.i.p.

cells

can

be found in the gut mucosa.34Furthermore

v.i.p.-secreting apudomas are not of neural origin.4 The suggestion that diarrhoea may be caused by agents other than v.i.p. seems self-evident. Indeed, a third of gastrinoma patients have troublesome diarrhoea, and this feature is also seem in the glucagonoma syndromedespite normal v.i.p. and in many cases normal pancreatic polypeptide (P.P.) levels.6 It is possible that P.P. may be associated with diarrhoea, though many patients with high plasma-p.p. values (e.g., with insulinomas) have no diarrhoea.6 We are studying a patient with diarrhoea, normal v.i.p., and high plasma-p.p. produced by hepatic metastases of a pancreatic P.P.-oma, and it is indeed possible that P.P. is responsible for the clinical symptoms. That v.i.p. is responsible for diarrhoea of v.i.p.-omas is incontrovertible. Infusions of v.i.p. in pigs producing similar blood levels result in severe diarrhcea.7 A third of pancreatic v.i.p.-omas

MACROPHAGES v. CANCER

most

with massive diarrhoea have absent tumour P.P. cells and normal plasma P.P. levels.6 Ganglioneuromas producing v.i.p. and 9 watery diarrhoea* are never associated with excess P.P. production. Departments of Histochemistry and Medicine, Royal Postgraduate Medical School, London W12

melanoma’ and with cancer of the prostate,2have emphasised the importance of macrophages in this form of immunotherapy. B.C.G. contact suppression of tumours is a hostmediated response since the organisms are not directly cyto-

cutaneous

toxic for

tumour

cells, but

treatment

is successful in animals

lacking full lymphocyte competence. Thus, B.C.G. contact therapy of syngeneically transplanted rat tumours is successful even in immunosuppressed animals,3 4 and rat tumours xenografted to athymic "nude" mice may be prevented from FACILITATION OF B.C.G. CONTACT SUPPRESSION OF HEPATOMA

D23

BY

SYNGENEIC MACROPHAGES

S. R. BLOOM A. G. EVERSON PEARSE

Strip. In Gaza asthma is an extremely common disease among both children and adults. While no exact figures exist concerning its incidence in the population, it is among the most frequent diagnoses made in the outpatient clinics and emergency room of our hospital, with a frequency reaching 10—20% of all children examined. In contrast with Godfrey’s findings, no significant difference in the incidence of the disease could be seen among children from city, village, or refugee camps. If any difM. G., Bloom, S. R., Polak, J. M., Albyquerque, R. H., Modlin, I., Pearse, A G. E. Lancet, 1976, i, 991. 2 Said, S I., Rosenberg, R. N. Science, 1976, 192, 907. 3. Polak, J. M., Pearse, A. G. E., Garaud, J.-C., Bloom, S. R. Gut, 1974, 15,

Bryant,

720. 4. Bloom, S

SIR,-Your editorial (July 3, p. 27) draws attention to the paucity of knowledge concerning the role of macrophages both in immunosurveillance and in immunotherapy of cancer. Recent results, from this and other laboratories, of investigations on the mechanism of action ofB.c.G. regionally applied to tumour deposits, such as has been well described clinically with

J. M. POLAK

IgE, PARASITES, AND ALLERGY SIR,—Iwas astonished to realise that a generalisation such as the one which appears in your editorial of April 24 (p. 894}-"there is evidence for an inverse relation between parasites and allergy: asthma and hay fever are rare in parts of the world where the population is heavily parasitised"-was based uniquely on the findings of Godfrey in the Gambia.’° While this may be true in the Gambia, it certainly is not in the Gaza

1.

E. E. LASCH

subsequently by Said and Rosenberg.2 However, not only a neural peptide, for numerous endocrine

and

R., Polak, J. M. in Gastrointestinal Hormones (edited by J. C. Thompson),p. 635. Austin, Texas, 1975. 5. Mallinson, C. M., Bloom, S. R., Warin, A. P., Salmon, P. R., Cox, B. Lancet, 1974, ii, 1. 6 Polak. J M , Bloom, S. R., Adrian, T. E., Heitz, Ph., Bryant, M. G., Pearse, A G. E. ibid. 1976, i, 328. 7 Bloom. S R., Mitchell, S. J., Modlin, I. (Unpublished). 8 Swift, P. G. F., Bloom, S. R., Harris, F. Archs Dis. Childh. 1975, 50, 896. 9 Bloom, S. R., Polak, J. M., Pearse, A. G. E. Lancet, 1973, ii, 14. 10 Godfrey. R C Clin. Allergy, 1975, 5, 201.

*Glaxo percutaneous

vaccine B.P., 3x10’ viable units/mg organisms, representing approximately 20% viability.

moist

weight

of

type of B.C.G. therapy.’ In contrast, treatment of animals with particulate silica, of a type known to be selectively toxic for macrophages, abrogates B.C.G.-mediated tumour contact suppression both in rats6 and athymic mice,6 indicating that macrophages play a primary and important role in this type of local therapy. Furthermore, whilst transplanted rat tumours normally contain a proportion of host macrophages, varying widely between tumour types, there is a distinct correlation between the maximum number of cells of each tumour that can be suppressed by contact with B.C.G. and the extent of its host macrophage infiltration.8 Thus, tumours containing 25-30% macrophages (e.g., chemically induced sarcomas) are highly susceptible to B.c.G. therapy, whereas those containing only 2-3% macrophages (e.g., mammary carcinomas) are less responsive. Most importantly, our findings

growth by this

1.

D. L., Eilber, F. R., Holmes, E. C., Cancer Immun. Immunother. 1976, 1, 93.

Morton,

Sparks,

F.

C., Ramming, K. P.

Merrin, C., Han, T, Klein, E., Wajsman, Z., Murphy, G. P Cancer Chemother. Rep. 1975, 59, 157. 3 Pimm, M. V., Baldwin, R. W Br J. Cancer (in the press). 4. Moore, M, Lawrence, N., Nisbet, N. W. Int. J Cancer, 1975, 15, 891. 5 Pimm, M. V, Baldwin, R. W. Nature, 1975, 254, 77. 6. Hopper, D. G, Pimm, M. V., Baldwin, R. W. Cancer Immun. Immunother. 1976, 1, 143. Chassoux, D., Salomon, J.-C Int J. Cancer, 1975, 16, 515. 8 Baldwin, R. W. Transplant. Rev. 1976, 28, 62.

2

7

256 indicate that enrichment of tumour deposits with macrophages facilitates tumour suppression by

syngeneic regionally applied B.C.G. (see table). The transplanted 4-dimethylaminoazobenzene-induced rat hepatoma D23 used in these studies normally contains approximately 10% host macrophages, and only 105 tumour cells are prevented from growth when injected subcutaneously in admixture with B.c.G. When, however, normal rat macrophages (peritoneal cells) are added to tumour-cell inocula to give a 50% final macrophage content, the maximum number of hepatoma cells prevented from growth by admixture with B.C.G. is raised at least 20-fold to 2x 106. Addition of macrophages alone had no effect on tumour growth. These observations indicate that the dilemma of the doctor will not be whether to stimulate the phagocytes but how to encourage them, once stimulated, to invade tumour deposits. In this context, preliminary work carried out at this laboratory on immunotherapy of experimental lung tumours shows that B.c.G.-stimulated macrophages when injected intravenously enter the lungs and can arrest .the growth of existing pulmonary

Controls

deposits.

Cancer Research Campaign Laboratories, University of Nottingham, Nottingham NG7 2RD

Hepatic D. G. HOPPER M. V. PIMM

ENHANCEMENT OF BILIRUBIN CLEARANCE AND HEPATIC HÆM TURNOVER BY ETHANOL

SIR,—During a study of ineffective erythropoiesis in various haematological disorders, which required measurement of hepatic bilirubin clearance and hepatic hsem turnover,’ we observed a striking increase in both these variables in a patient with macrocytosis of chronic alcoholism who had consumed 5 litres of cider daily for many years. Liver-function tests were normal except for a slightly raised serum-5-nucleotidase (25-7 I. u ./1, normal range 1.6-17) and y-glutamyl transpeptidase (86 I.U./1, normal range 0-60). Our patient had a threefold increase in hepatic haem turnover (3.96 µmo1/kg/day, normal range 1.30±0.551) and was the only case in a series of thirteen patients with various

haematological disorders in whom an increase was observed (see figure). Total daily bilirubin turnover was increased (6.51 mg/kg/day, normal range 3.90±0.301), consistent with the inin hepatic hsem turnover, but the plasma unconjugated bilirubin was maintained at a normal level (0.36 mg/dl) by a twofold increase in the rate of hepatic clearance of bilirubin (1.25 ml/min/kg, normal range 0.65 ±0.182). This patient was the only one of all those studied to show either increased hepatic heem turnover or enhanced hepatic clearance of bilirubin, and it is therefore likely that these abnormalities were related to her chronic ethanol consumption. Furthermore, both increased early labelled bilirubin production and increased bilirubin clearance are produced by phenobarbitone34 and many of the effects of ethanol on the liver resemble those of phenobarbitone. Both drugs stimulate microsomal drug oxidations and produce an increase in the concentration of the hepatic microsomal cytochromes p 450 and bs.6 However, enhancement of early labelled bilirubin production by ethanol has not previously been reported. Ethanol is metabolised partly by a microsomal drug-oxidising system’ and the increased hepatic heem turnover in this patient may therefore be attributed to increased turnover of microsomal ha:m crease

1.

Samson, D., Halliday, D., Nicholson, D. C, Chanarin, I. Br. J. Hœmat. 1976, 34, 29. 2. Berk, P. D., Howe, R. B., Bloomer, J. R., Berlin, N. I. J. clin Invest 1969, 48, 2176. 3. Schmid, R., Marver, H. S., Hammaker, L. Biochem. biophys. Res. Comm. 1966, 24, 319. 4. Blaschke, T. F., Berk, P. D., Rodkey, F. L. Clin. Res. 1972, 20, 407 (abstr.). 5. Rubin, E., Lieber, C. S. Anna. intern. Medi. 1968, 69, 1063. 6. Rubm, E., Hutterer, F., Lieber, C. S. Science. 1968, 159, 1469. 7. Lieber, C. S., Decarli, L. M. ibid. 1968, 162, 917.

hcem turnover,

Patients

showing single abnormal value(S).

p. 450, associated with induction of ethanol oxidase and other microsomal drug-metabolising enzymes. This patient thus shows two abnormalities of liver function, increased hepatic haEm-turnover rate and increased hepatic clearance of bilirubin, which have been previously observed after phenobarbitone and which in this case seem to be metabolic effects of ethanol. DIANA SAMSON Division of Hæmatology, D. HALLIDAY Clinical Research Centre, I. CHANARIN Harrow, Middlesex HA1 3UJ

proteins, including cytochrome

TESTICULAR LEUKÆMIA AND TEMPERATURE

SIR,—Acute lymphocytic leukaemia of childhood

can

persist

in extramedullary sites even after successful marrow remissions have been achieved. Recurrence in the central nervous system (C.N.S.) can be explained by the concept of a pharmacological sanctuary behind the blood/brain barrier. Another favourite site for extramedullary leukaemia is the testis. The explanation for this is not as satisfactory as for C.N.S. leukmmia. There is not usually thought to be an anatomical or physiological blood/testis barrier, though a barrier for colchicine has been claimed.’ Post-mortem examinations suggest far less frequent involvement of ovaries than testes. While the percentage in series varies widely, the ratio of testicular to ovarian involvement is usually 2/1. We have lately been doing routine biopsies of both testes when one or both seemed clinically involved. In 9 cases where bilateral biopsy was done at time of clinical involvement of only one testis, 8 had bilateral leukaemia and 1 had lymphoid infiltrates, though not clearly malignant. This experience of finding bilateral disease is shared by others. We lately did a testicular biopsy on a boy who had unilateral cryptorchidism. This child had successfully completed 31 years of intensive chemotherapy for acute lymphocytic leukaemia without relapse. 8 months after cessation of treatment his only palpable testis enlarged. He had a biopsy of this gonad and an orchiectomy was done on the undescended side. The biopsy was positive for recurrent leukaemia but the excised gonad was negative on examination in toto. Testicular function depends on lowered temperature in the scrotum. Conversely, chemotherapeutic effects are said to be enhanced by temperature elevation.2 The testicle might, therefore, act as a sanctuary for leukaemic cells because of the dec-

or recur

1. 2.

Gureysse-Pellisier, A. Bull. Histol. appl. Physiol. Path, 1942, 19, Cavaliere, R., and others, Cancer, 1967, 20, 1351.

81.