262

perpendicular strip of

any chosen material. If there

is

any

adhesion between the chosen material and the clot, the amount of clot builds up with time. If the forces of adhesion are not very great the clot soon becomes heavy enough to part from the substratum. Thus by weighing the strip with the attached clot at intervals until the clot falls off, an idea of the forces of adhesion can be gained. Some examples will indicate the kind of results which may be obtained. When the perpendicular strip was coated with cholesterol the clot did not fall off during an experiment lasting 2.5 h by which time the weight of curd had reached 9 g (on a strip 25 x1 cm). When the coating was of lecithin some curd fell away after 25min when the weight was 0-55 g and all the curd fell away between 60 and 70 min just after the weight had reached 1.5g. When the surface was covered with dialysis membrane (’Viscose’, regenerated cellulose) the weight of adhering clot was negligible until 100 min when it reached 1.00 g and then some fell away. When the surface was a strip of beef aorta the clot built up rapidly but it was then found to be adhering to the cut edges only. A deep-frozen and thawed aorta turned inside-out also showed strong adhesion and experiments need to be done with uncut fresh material, but they will not be undertaken in this laboratory. Results with a number of other surfaces suggested, although they were insufficient to prove, that adhesion was minimal if not zero when the surface was very hydrophilic and a compound of carbon, hydrogen, and oxygen only. Even then adhesion occurred eventually unless calcium ions could be continuously removed (e.g., by irrigation of dialysis membrane from the other sideB National Institute for Research

in

Dairying,

Shinfield, Reading,

N.

Berkshire RG2 9AT

J.

BERRIDGE

EAR, JANEU, AND HEART SiR,—1 read with interest the letter

by

Saxena et al. I

recently had occasion serendipitously to abort an attack of paroxysmal atrial tachycardia while performing routine otoscopy. The clue was the sudden bout of coughing occasioned by both speculum insertion and retraction of the pinna. The "batting" tachycardia 240-280/min settled over the ensuing 20 min whereupon the staccato cough that had persisted after removal of the speculum also ceased. There have been other methods of increasing vagal tone (e.g., the diving reflex2 and wearing of an ice-collar3 but I think none simpler. The infant-a boy aged 3 months-has had no further attacks or evidence of any other cardiac anomaly. Cardioversion or digitalis was not required. Children’s Dublin 1, Ireland

Hospital,

J. DAVID O’KANE

BROMOCRIPTINE AND SECONDARY

AMENORRHŒA

SIR,-In reply out

that there

to

were

the letter by Jacobs et a1.4 we would point 5 of 18 and not 9 of 18 patients with nor-

moprolactinaemic amenorrhoea in whom we found evidence for ovulation during bromocriptine treatment.5 Like Jacobs et al. we also were surprised by the result, which became evident only after we measured the prolactin levels which were not known when treatment began. Now that the question has been Saxena, S. R., Solanki, D., Kataria, M. S. Lancet, 1976, i, 1415. Wildenthal, K., Leshin, S. J., Atkins, J. M., Skelton, C. L. ibid. 1975, i, 12. 3. Murphy, R. J. Am. med. Ass. 1960, 172, 555. 4. Jacobs, H. S., Franks, S., Hull, M. G. R., Steele, S. J., Nabarro, J D. N. Lancet, 1976, i, 1402. 5. Seppälä, M., Hirvonen, E., Ranta, T. ibid. 1976, i, 1154.

1. 2.

raised as to whether bromocriptine has anything to do with the transient recovery of some patients with normoprolactinaemic amenorrhcea we fully agree that a double-blind controlled trial is needed. I and II of Obstetrics and Gynæcology, University Central Hospital, and Department of Serology and Bacteriology, University of Helsinki, Finland

Departments

M. SEPPÄLÄ E. HIRVONEN T. RANTA

THE FUTURE OF COMMUNITY MEDICINE

SIR,-While I appreciate the honour of having my name a Lancet editorial, your use of my statement’ on the

cited in

importance of epidemiology

to

public-health planning

occurs

part of your argument that epidemiology is a useful management tool for improving health services.:2 My statement referred to the way in which an epidemiological perspective applied to today’s health techniques would have warned us about a new rising tide of disease and disability produced by the well-intentioned health services you wish to see

as

applied more efficiently. I pointed out that society’s efforts to reduce the prevalence of disease and disability should take account of the fact that our health techniques have developed in such a way that the more efficiently they are applied the higher will rise the prevalence of such conditions as Down syndrome and its associated disabilities. Antimicrobial drugs and other advances in health technology have assembled an array of devices for averting death in the presence of chronic conditions, while we continue to lack means for either preventing or curing these conditions: the newer means for "extending life" are in fact too often means for extending disease and disability. Consequently, from a public health point of view, more systematic application of such techniques will still further raise the prevalence of disease and disability and thus heighten the need for even more medical care and social services. Epidemiology is needed to recognise these new patterns (a service it too rarely performs) and it is also needed to find the preventable causes of conditions such as Down syndrome, senile brain disease, diabetes, Alzheimer disease, pernicious anaemia, and other chronic, incurable conditions whose fatal complications today’s techniques are so successful at thwarting. The resulting rising prevalence-rates call for new priorities, not just for health and social services but for epidemiological research especially, which must be directed toward finding modifiable precursors of such growing conditions. That is the burden of the statement you cited in support of using epidemiology as a health service management tool. It can be so used. But I hope that more epidemiologists would prefer to use their skills in spotting the hazards created by new health techniques and discovering means to prevent the new diseases of medical progress. On which problems epidemiologists deploy their skills will depend in part on where society offers most in financial and professional status rewards. Department of Mental Hygiene, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205, U.S.A.

ERNEST M. GRUENBERG

S:R,—The article by Dr Heath and Dr Parry (July 10, p. 82) filled me with foreboding. I am a community physician who is on the brink of a career in community medicine. I use the word brink rather than beginning, after much thought. When I entered public health five years ago, medical administration was something done at regional level. I was not sure then what it involved, and am still not sure, although that is E. M. in Higher Education for Public Health: Milbank Memorial Fund Commission. New York, 1976.

1.

Gruenberg,

2.

Lancet, 1976, i, 78.

a

report of the

Letter: Bromocriptine and secondary amenorrhoea.

262 perpendicular strip of any chosen material. If there is any adhesion between the chosen material and the clot, the amount of clot builds up w...
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