875

the host’s ability to manifest an immunological responseof sufficient magnitude to destroy aberrant cell-lines.

Immunology Section, Renal Unit,Memorial Hospital, and

the Department of Medicine,Southern Illinois University

School of Medicine,Springfield, Illinois 62701, U.S.A. R. J. ABLIN.

TOTAL LEUCOCYTE COUNT IN AFRICANS

SiR,—Shaper and Lewis 1 record white-cell counts ofAfricans and Europeans in Kampala. The findings in 160African Makerere students examined in 1962 were 5500

per 1. (95;o confidence limits 2200-8900); these figuresare slightly higher than those for Kampala Africans ex-amined in 1968 (5100 [1900-8300]) and both are con-siderably lower than those found in Kampala Europeans(6400 [3600-9200]). We have recently confirmed the

relatively low white-cell count of African students. Bloodcollected from the 124 second-year medical students as

part of their training was analysed on a Coulter Model S.The students ages ranged from 21 to 24 years; there were111 males and 13 females. The difference in the meanwhite-cell count between the sexes was not very significant(0-025 < p < 0-5) and the analysis given in the table includesboth sexes. The differences between the African andAsian students is highly significant (p < 0-001).

Asian students ,.1.J) "’;1:- ’-c&Uacute;’U , -JJ GVV

These results show that the total white-cell count islower in Africans than in Asians living in the same generalenvironment. This study does not include a differentialwhite count, but it seems likely that, in view of the work ofothers, the lowered white count is due to a relative neutro-penia in the Africans.

Shaper and Lewis 1 believe this to be of genetic origin,but Ezeilo,2 who studied the leucocyte counts of neonatesin Lusaka, believed that the lowered counts in adultAfricans has an environmental basis. We hope to in-

vestigate this matter further; perhaps both play a part.

Makerere University,Kampala, Uganda.

H. J. WOODLIFFP. K. KATAAHAA. K. TIBALEKAE. NZARO.

PREVENTION OF INCONTINENTIA PIGMENTI

SIR,-It is likely that the reliable selection of fetal sexis an imminent scientific advance that will have a profoundeffect on sex-linked disorders. For example, a womanknown to carry the gene for haemophilia would choose tobear daughters because of the 50% chance that a son wouldbe haemophilic. Half of the healthy daughters would,however, carry the gene, and the number of carriers wouldincrease through the generations if the total number of

offspring were maintained. Among the clinically serioussex-linked conditions incontinentia pigmenti (Bloch-Sulzberger) seems to be unique in that the proven cases(who are predominantly, if not exclusively, female) transmitthe gene to only 50% of daughters. Affected sons are un-known and they do not transmit the condition to theirchildren. Therefore, it seems likely that the affected XYfertilised ovum or conceptus is non-viable.

Apart from its bizarre cutaneous presentation, which initself is ultimately trivial, incontinentia pigmenti in at

1. Shaper, A. G., Lewis, P. Lancet, 1971, ii, 1021.2. Ezeilo, G. C. East Afr. med. J. 1972, 49, 93.

least a third of cases is associated with serious neurologicaldisorder, and a similar number have eye lesions. It causesmental and physical handicap and is perhaps a form ofneuroectodermal dysplasia.

Therefore, if affected females choose to have male

offspring a reduction of fertility may result, but theywill bear only healthy sons, and, in addition to the preven-tion of handicap, the frequency of the harmful gene willbe reduced because its transmission will be blocked.

West Middlesex Hospital,Isleworth, Middlesex. N. J. O’DOHERTY.

IMMUNOPROPHYLAXIS AND

IMMUNOTHERAPY OF LEUK&AElig;MIAWITH B.C.G.

SiR,&mdash;The suggestion that non-specific immunotherapywith bacillus Calmette Guerin (B.c.G.) prolongs the dura-tion of remission in humans with acute lymphocyticleukaemia was reported by Mathe et al.1 Davignon andcolleagues reviewed data from the Province of Quebec,Canada, and reported that death from leukaemia was halfas common in B.c.G.-vaccinated as among non-vaccinated

people less than 15 years of age, for each of the years1960-63.2 Dr. Davignon’s communication provoked anumber of letters and an article in your journal whichdisagreed with her findings. 3-8We have reported that Gross virus-induced murine

leukaemia is a valuable model to study various approachesin the immunotherapy of leukaemia. 9 ,lOW e wish to bring tothe attention of your readers a recent experiment in whichB.c.G. was evaluated in the murine model for its immuno-

prophylaxis and immunotherapeutic properties.l150 syngeneic C3H/eB/FeJ newborns were divided into two

groups. At two weeks of age, one group received 1 mg. ofB.c.G. (Chicago Research Foundation) intraperitoneally, and a

IMMUNOPROPHYLAXIS AND IMMUNOTHERAPY OF MURINE LYMPHOMA

WITH B.C.G.

Figures in parentheses show number of mice in each group.sq. = subcutaneous administration of leukeemic cells.

control group received an equivolume (0-1 ml.) of Hanks’balanced salt solution. At nine weeks of age the mice were givena single subcutaneous inoculation of 1 x 106 isogeneic C3H/eB/FeJGross virus-induced leukxmic cells which had been cultivatedin vitro and passed in vivo. 16 of 25 mice in each group developedpalpable lymphoma within two weeks. When the lesions measured1-5-2 cm. in diameter, mice from each group were furthersubdivided so that 10 mice were given a single intraperitoneal

1. Math&eacute;, G., Amiel, J. L., Schwarzenberg, L., Schneider, M.,Cattan, A., Schlumberger, J. R., Hayat, M., De Vassal, F.

Lancet, 1969, ii, 697.2. Davignon, L., Lemonde, P., Robillard, P., Frappier, A. ibid.

1970, ii, 638.3. Stewart, A. M., Draper, G. J. ibid. p. 983.4. Waaler, H. ibid. p. 1314.5. Hems, G., Stuart, A. ibid. 1971, i, 183.6. Berkeley, J. S. ibid. p. 241.7. Kinlen, L. J., Pike, M. C. ibid. 1971, ii, 398.8. Stewart, A., Draper, G. ibid. 1971, i, 799.9. Davignon, L., Lemonde, P., St.-Pierre, J., Frappier, A. ibid.

10. Comstock, G. W. ibid. 1971, ii, 1062.11. Finklestein, J. Z., Byfield, J., Tittle, K. L., Imagawa, D. T. Rev.

Europ. &Eacute;tudes clin. biol. 1972, 17, 287.

876

injection of cyclophosphamide (1-3 mg. per 10 g. body-weight).At this dose the drug caused regression of the lesion such thattumours were no longer palpable in all treated mice. 6 of the 10animals from each treated group were then given 1 mg. ofB.c.G. i.p. twice weekly. All mice (treated and non-treatedcontrols) subsequently developed progressive disease and diedin two to three weeks. There were no differences in the survivalof the B.c.G.-treated animals and their appropriate controls.

This experiment (outlined in the accompanying table)suggests:

(1) B.C.G. administration to suckling C3H/eB/FeJ mice doesnot protect them from challenge with a potentially lethal numberof viable isogeneic leukxmic cells.

(2) Mice who have progressive lymphomas will respond toanti-tumour chemotherapy irrespective of whether they hadpreviously received B.C.G. immunisation.

(3) Administration of B.C.G. to mice who no longer havepalpable disease does not prolong their life when compared toappropriate controls. This is true whether or not B.C.G. hadbeen given as an immunoprophylactic.These experiments seem to support the many investi-

gators who have commented in your journal, since B.C.G.failed to demonstrate activity as an immunoprophylacticor as an immunotherapeutic.

Department of Pediatrics,Harbor General Hospital Campus,

University of California,Los Angeles,

1000 West Carson Street,Torrance, California 90509, U.S.A.

JERRY Z. FINKLESTEINKAREN L. TITTLEDAVID T. IMAGAWA.

POSTPRANDIAL SERUM-CHOLESTEROL

SIR,-A high total-serum-cholesterol is widely acceptedas an indication for detailed evaluation of serum-lipids.For this purpose, total cholesterol is usually determinedafter a short period of complete fasting. While the main-tenance of a controlled diet for at least a week preceding astudy of serum-lipids is justified, is complete short-termfasting necessary before cholesterol determination ? Toanswer this question an experiment was conducted.

Six randomly selected volunteers (table I), all white-collar workers, participated. At least during the preceding

TABLE I-STATISTICAL DATA AND SERUM-CHOLESTEROL CONCENTRA-

TIONS OF PARTICIPANTS

week they were eating reasonable American diet withoutany dietary excesses. Between 4 and 5 P.M. on day 1 ofthe experiment, a meal was served (table 11). After thismeal participants consumed no food, but water was

allowed ad libitum. In the morning of day 2-15 hoursafter the afternoon meal-blood was drawn for cholesteroldetermination (fasting cholesterol). Breakfast was served

immediately thereafter, and lunch 4 hours later (table 11).The second blood-sample was obtained 1 hour after lunch(postprandial cholesterol). Between breakfast and lunch,participants ate no food but drank water ad libitum, andthey engaged in their regular daily chores. Serum wasextracted with a boiling mixture of acetone/ethanol (1/1),saponified with 50% aqueous potassium hydroxide, andtotal cholesterol precipitated with digitonin and determined

1. Levy, R. I., Fredrickson, D. S. Am. J. Cardiol. 1968, 22, 576.

TABLE II-DIET

* Moderate consumption of alcohol probably does not affect serum-cholesterol levels. 3

t Soybean/cottonseed oil.

spectrophotometrically at a wavelength of 202-203 fi!).,2No significant difference between fasting and postprandialtotal-serum-cholesterol was observed (table i).

This experiment indicates that complete short-term

fasting before total cholesterol determination in serum ofindividuals who avoid dietary excesses is (a) unnecessaryand (b) may cause overestimates of postprandial cholesterollevels.

Veterans Administration Hospital,Salt Lake City, Utah 84113,

U.S.A. LUDVIK PERIC-GOLIA.

VITAMIN C AND SERUM-CHOLESTEROL

SIR,-Dr. Spittle 4 reported that the daily intake of1 g. of vitamin C results in a significant lowering of serum-cholesterol levels in young adults. At the time that this

interesting and potentially important observation was

published, we had just begun a large-scale double-blindtrial of the effect of the same daily dose of vitamin C onthe incidence of the common-cold. Although it was toolate for us to collect any pre-trial blood samples, weattempted to verify Dr. Spittle’s findings by obtaining afasting blood-sample from 41 of our subjects during thelast ten days of the trial, and a second sample approximatelysix weeks later. (Correspondence with Dr. Spittle estab-lished that she observed a return to normal cholesterollevels in her subjects two or three weeks after stopping thehigh vitamin-C intake.) Sera were kept frozen, andcholesterol determinations subsequently carried out on

the paired samples, using the Carr and Drekter method.All 41 subjects were aged between 18 and 24, and had beenon the vitamin or placebo tablets for approximately 14weeks. When the tablet-code was broken it was foundthat 18 of the subjects had been on the vitamin and 23 onthe placebo (mean ages 20-9 and 21.6 years, respectively).

Contrary to the hypothesis being tested, not only was themean serum-cholesterol of the vitamin group higher thanthat of the placebo group during the last 10 days of thetrial (194 compared with 185 mg. per 100 ml.), but there

2. Weigensberg, B. J., McMillan, G. C. Am. J. clin. Path. 1959, 31, 16.3. Heyden, S. in Atherosclerosis (edited by F. G. Schettler and

G. S. Boyd); p. 618. Amsterdam, 1969.4. Spittle, C. R. Lancet, 1971, ii, 1280.5. Anderson, T. W., Reid, D. B. W., Beaton, G. H. Can. med. Ass. J.

1972, 107, 503.