1284 ÆTIOLOGY OF PRE-ECLAMPTIC TOXÆMIA SIR,-Professor Gray and Dr. Rinsler in their letter of April 12 claim to have demolished the foundations of the
long and widely held belief that the adrenal cortex plays a major role in the xtiology of pre-eclamptic toxaemia and eclampsia. With respect I submit that their claim cannot be substantiated. Nowhere in my paper of Jan. 18 did I suggest that the glucocorticoids were responsible for the pre-eclamptic syndrome. On the contrary, I expressly stated that the mineralocorticoids were " probably the hormones chiefly involved in pregnancy toxaemia ". I also gave reasons for believing that aldosterone was not the responsible mineralocorticoid. I now suggest that it may be deoxycortone acetate or a compound with similar action.
It would, indeed, be rash to base an opinion regarding the secretory activity of the adrenal cortex on histological appearances alone, for they are notoriously difficult to interpret. There is, however, another possible source of active hormones-namely, the placenta-which is known to contain substances that possess adrenocortical-like activity, though the yield of bioactivity is much less than that from adrenal tissue. It is not yet known whether the active factors have been produced in the placenta or simply stored there after having been transported from some extraplacental source,1 though there are certain facts that favour the adrenal as the main site of their production. As to potassium excretion, which is usually increased in adrenal cortical hyperactivity, it is well known that there are circumstances in which it is not, and until more is known about it, it would be wise to refrain from basing important conclusions upon it. I thank all the correspondents who have contributed to the discussion on my paper. I do not wish to support any particular theory or point or view on this difficult problem merely because it is my own, but only to arrive at the truth. F. J. BROWNE.
thiazine (pecazine) (’ Pacatal ’), or benzhexol hydrochloride (’ Artane ’), or a combination of these drugs. 3 patients suffering from unilateral tremor and rigidity were subject to pallidectomy before attending my clinic, and after the operation the disease rapidly spread to both sides. It is concluded that surgery offers little hope of relief for those suffering from
parkinsonism. Dudley
Road Hospital, Birmingham.
R. O. GILLHESPY.
VISITING MENTAL HOSPITALS
SIR,—Ihave read Mr. Woodley’s letters of May 17 and June 7 with amazement, for I believe that medical superintendents in general welcome visitors to their mental
hospitals. Here
fortunate in that
we are
we
have
a
very active
League of Friends, who make a special feature of visiting lonely patients, and as all the wards are open they come in and go out at any convenient time as they please. If Mr. Woodley and his party care to visit us I shall be pleased to give them the same facilities. The Central Hospital, nr. Warwick.
E. S. STERN.
RETINAL PHOTOGRAPHY
H. DEGENHARDT, F.B.O.A., a director of and Co. Ltd., Carl Zeiss agents, writes: Degenhardt Your editorial on retinal photography in the issue of May 10 saysIn this respect modern retinal cameras are less satisfactory than the original Zeiss-Nordenson camera; for with them the photograph records a smaller area of fundus and consequently...’ This may be true of some modem retinal Mr.
A.
"
cameras but it is a criticism which certainly may not be levelled against the new Zeiss instrument. In this the field of view is considerably larger than in the old Nordenson and as the magnification is less it follows that the area of fundus recorded is appreciably larger than in the earlier instrument."
Public Health SURGERY OF PARKINSONISM SiR,—Ihave read Mr. Oliver’s communication (May 24, p. 1121) describing the surgical techniques used in the treatment of Parkinson’s syndrome and would offer the
following
comments.
Whereas the postmortem lesions present in non-infective parkinsonism are well understood, the precise xtiology remains entirely unknown. Surgical procedures are purely empirical and are not based on any sound physiological theory. Furthermore, if some improvement in the rigidity is achieved by the various operations described, relapse is certain as the lesions in the midbrain progress. I have recently discussed with eminent American authorities the minimum indications which must be present before surgery or irradiation by multibeam ultrasonic waves is considered, and we agreed they are:
(1) Unilateral rigidity and tremor, preferably in one limb only. (2) Absence of other serious disease (this means that the patients must be a good operative risk below the age of 50). (3) Failure of drug therapy. I have recently studied in great detail the case-histories of 398 patients attending my Parkinson’s clinic regularly, and only 15 were found to have these characteristics and all have res-
ponded satisfactorily to B-dimethylaminoethyl-2-methylbenzhydryl hydrochloride (’ Disipal ’), ethopropazine hydrochloride(’ Lysivane ’),10-(l-methyl-3-piperidylmethyl)-pheno-
Poliomyelitis Vaccination WITH the arrival of a further 1,000,000 doses of Canadian Salk vaccine, the initial order of 4,000,000 doses placed with the Connaught Laboratories, Toronto, last September, has been completed. This final consignment was not expected until later this month, but the laboratories hastened delivery to help the current British vaccination programme. All the Canadian Salk vaccine has passed the M.R.C. tests. This latest consignment brings the total of vaccine, both British type and Salk, which has been distributed throughout Great Britain, to just over 131/2 million doses, of which 91/2 million have been distributed since last January. Registration returns from the local authorities show that by April 30 just over 6,250,000 children and other priority groups had registered, of whom just over 3,640,000 had received both injections, or were awaiting their second. The present position is that with the latest Canadian batch enough vaccine will have been distributed to cover all those registered and awaiting vaccination on April 30, but some allowance must be made for unavoidable wastage. A statement from the Ministry of Health says " as far as we can judge " there should now be enough vaccine to cover practically all of those in the priority groups who had registered by April 30. Registrations are, of course, continuing and vaccination will also go on during the summer months. Further batches of vaccine, mostly Salk, will continue to be issued to keep pace with new registrations ". ’
1.
Johnson,
R.
H., Haines, W. J. Science, 1952, 116, 456.