209 the same incidence of cervical cancer as the rest of the population.5J6 If it were possible to separate the semen samples examined into two groups-i.e., from circumcised and non-circumcised men and also to compare a group of Jewish men with a group of non-Jewish circumcised men-one might be able to explore the issue of the causative factor more fully. If a difference were found, the question might arise as to whether semen is contaminated by smegma; and it would be of interest to know whether histone and protamine are found in smegma. The findings of Melamed et al. suggested that a diaphragm interposed between the penis and cervix reduced the incidence of carcinoma, although this view has been disputed.8,9 If Melamed’s findings were to be confirmed, that would be additional evidence of the importance of the factor described by Reid et al. 13 St. John Street, Manchester M3 4DQ

BERNARD SANDLER

HUMAN PLACENTAL LACTOGEN IN LATE PREGNANCY SIR,-The paper by Dr Letchworth and his colleagues,1 suggesting routine screening of human placental lactogen (H.P.L.) in maternal serum in late pregnancy has prompted reports of false-positive tests (low H.P.L. values when pregnancy and delivery were normal)2,3 and false-negatives.4 We have seen two pregnancies in which maternal H.P.L. levels were low in the absence of placental insufficiency and in the presence of normal oestriol values. HORMONE MONITORING IN TWO PREGNANCIES WITH NORMAL

mg/24’ h.

Stewart, H. L., and others, J. nat Cancer Inst, 1966, 37, 1. Jones, E. G., MacDonald, I., Breslow, L. Am. J. Obstet. Gynec. 1958, 76,

1. 7. Melamed, M. R., Koss, L. G., Flehinger, B. J., Br. med. J. 1969, iii, 195. 8. Wachtel, E, Husain, O. A. N. ibid. p. 412. 9 Swyer, G. I. M. ibid. p. 471.

A. KENNEY* J. WOODFORDE SCOTT C. A. HALL

’Department of Obstetrics and Gynaecology, Westminster Hospital, London SW1

IN-VITRO ACTIVITY OF NEW CEPHALOSPORIN (HR 756) AND CEFAZOLIN mentioned several ’HR 756’. We have in vitro the antibacterial activity of HR 756 (Hoechst/Roussel) with that of cefazolin (Bristol) against 109 strains of gram-positive bacteria and 522 strains of gram-negative bacteria. The chemical name tor HR 756 is 3-acetoxy-

SiR,—Your editorial

interesting compared

new

on

cephalosporins’

compounds, including

methyl-7 [(2- (2-amino-4-thiazolyl)-2-methoxy-imino acetyl) amino]-ceph-3-eme-4-carboxylic acid (syn isomer), sodium salt. These strains were isolated in our routine laboratory from clinical material and identified by standard methods, and

Plasma-total-oestriol

In the first case plasma H.P.L. levels ranged from 0-8 to 2-4 mg/1 between 32 and 38 weeks gestation, while the urinary cestriol levels were from 43 to 93 p.mol/24 h. Because of the doubt about placental function an unsuccessful, and in retrospect unnecessary, attempt was made to induce labour at 38 weeks. The infant was delivered by lower-segment cassarean section and was a live female weighing 3-250 kg. The placenta was healthy with no infarcts. In the second case, H.P.L. was unrecordable in plasma while levels of plasma-total-oestriol ranged from 295 to 1360 nmol/1 between 32 and 39 weeks gestation. Labour began spontaneously at 39 weeks and the infant, delivered with Kielland’s forceps because of second-stage 5. 6.

Departments of Obstetrics and Chemical Pathology, Kingston Hospital, Kingston-upon-Thames, Surrey

included:

OUTCOME

Urinary oestrogen: 1 pmoV24 h0.29 I nmol/1=’0 .29 ng/ml.

delay, was a live male weighing 2.570 kg. The placenta was healthy with no infarcts. Urinary oestrogens were estimated by Technicon ’AutoAnalyzer’ with a method based on that of Hainsworth and Hall. Plasma-total-oestriol and plasma-H.p.L. were measured by radioimmunoassay kits (Radiochemical Centre, Amersham). These cases illustrate the value of measuring the levels of at least two hormones when monitoring placental function. In some normal pregnancies, oestrogen levels are abnormally low (e.g., during maternal corticosteroid therapy) and it now appears that the same may apply to levels of ’plasma-H.P.L. although the mechanism for this is not clear.

Kelisky,

R. P.,

1. Letchworth, A. T., Slatley, M., Dennis, K. J. Lancet, 1978, i, 955. 2. Bradford, W. P., Hargreaves, T. ibid. p. 1213. 3. Trolle, D., Gaede, P., Pedersen, H. ibid. July 8, 1978, p. 105. 4. Rao, L. G. S., Plenderleith, W. ibid. 1978, i, 1213.

Dubrow, H.

t2 3-lactamase positive (supplied by U.K.). :j:6 3-lactamase positive.

Dr Pist,

Antwerp,

and Glaxo,

an almost similar in-vitro Cefazolin towards was slightly more activity staphylococci. active than HR 756 against Staph. albus, although the difference was not statistically significant. Most of the staphylococci were as resistant to HR 756 as to cefazolin. HR 756 was 3-5 5 times more active on pneumococci than was cefazolin. The difference in activity between HR 756 and cefazolin is particularly striking for the Enterobacteriacese. HR 756 was over 1600 times more active than cefazolin against S. marcescens and 1000 times more active against E. cloaca. The mean M.l.c. values of HR 756 and cefazolin for the enterobacter strains tested were 0-080+0-008 mg/l and 85-190 + 11-565 mg/1, respectively. All the Enterobacteriacex were fully sensitive to HR 756. Almost all the pseudomonads, although they were more susceptible to HR 756 than to cefazolin, may be defined as resistant (M.I.c.s>16 mg/1). HR 756 was significantly more active against H. influenzae and N. gonorrhaeae than cefazolin

HR 756 and cefazolin exhibited

5. Hainsworth, I.R., Hall, 1. Lancet, 1978, i, 863

P.E. Clinica chim. Acta. 1971, 35, 201.

210

(P