997 TONSILLECTOMY of April 20 was stimulated by annotation SiR,-Your my " Tonsils and Adenoids : Evaluation of Removal in 50 Doctors’ Children,"1 and it seems a little unfair, in view of my carefully worded title, to complain that I did not have a control series or say how many doctors’ children I had decided not to operate upon in the same period of time. My belief that the operation was of great benefit for the conditions for which I undertook it was confirmed by my study of the results in these 50 doctors’ children, and I would have felt a little unhappy and certainly not very helpful to my colleagues if I had refused to operate upon some of their children in order to use them as controls. Many experienced general practitioners and peediatric physicians believe as I do, and I wonder if you are justified in stating that " it is fairly well known that introduction of controls shows that the operation makes no impressive difference." That statement is based on a small series which you suggested2 would have shown the same result whatever the number. Comparable controls are very difficult to come by, and the numbers would have to be very large to equal out the variations. If you had applied the same kindly thought, exercising unbiased editorial outlook, to my small series, I think you would have been getting nM.rer the truth. JAMES CROOKS.
HAZARDS OF EPOXIDE RESINS SIR,—Your annotation of April 20 in my opinion calls for comment. A distinction should be drawn between the resin and the catalyst, as well as the finished polymerised resin product. My experience with the amine catalysts over the past 9 years has shown that the amines are the most dangerous hazard and sensitisation to any one is liable to cause further sensitisation to others. Boas-Traube et al.3 and Dernehl4 reported on the amines as skin poisons long enough ago to warn of the need for caution. There is also the further problem of dangers arising from the partially polymerised final compound, which if drilled, sawn, or otherwise worked may give off a fine dust which is also a marked irritant when inhaled.5 You state that manufacturers of resins and hardeners If they are, are well aware of the hazards involved." then it appears to me that they could have done much more to prevent the trouble. They have not been outstandingly cooperative ; in fact it is known that one company in U.S.A. had carried out considerable research on the toxicity of the glycidyl ethers, closely related compounds, and published its results in 1954. It is also known that another large producer in Europe has been investigating these compounds for some years without publishing data. In spite of this, the information on prevention has not been passed on in a satisfactory manner to users. It would appear that question of international patents complicates the publishing of complete data of the processes. I am indebted to Mr. W. Whitby for clarifying the position : he informs me that "in the U.S. the situation is quite different from that on the Continent of Europe because the U.S. Courts have forced the companies under the anti-trust laws, and also under the rulings re the Devoe and Raynolds patents, to form a patent pool. This has prevented to some extent the hold that " X " has on some patent operations in Europe. I discovered these various things in attempting to get information at an early date." As far as prevention is concerned, I do not permit the use of gloves in the factories under my supervision. The "
1. 2. 3.
Practitioner, 1957, 178, 215. Lancet, 1955, ii, 810. Boas-Traube, S. G., Dresel, E. M., Dryden, I. G. C. Nature, Lond. 1948, 162, 960. 4. Dernehl, C. V. Industr. Med. Surg. 1951, 20, 541. 5. Bourne, L. B. International Congress of Industrial Medicine, Naples, 1954 ; Trans. Assoc. industr. med. Off. 1956, 6, 94.
sticky compounds cause the fingers of the gloves to adhere to each other. They dry and get hard, reducing An adequate barriermanual dexterity considerably. " no-touch " technique, cream, good washing facilities, a and reasonable engineering application have been adequate to prevent any cases. The recent introduction of a resin-removing cream has eased the situation considerably. This will remove even the hardened resin from the skin without damage to the epithelium. Unfortunately epoxide resins and amine catalysts are used in many small factories where no medical facilities are available and where the knowledge of protective methods is practically non-existent. L. B. BOURNE Senior medical
officer, A.C. Cossor Limited.
THIRTY-MINUTE SCREENING TEST FOR PHÆOCHROMOCYTOMA SIR,—I wish to add my support to Dr. Frazer’s remarks (May 4) on this test. With this method, I too have recovered only about 30% of both noradrenaline and adrenaline added to urine, using either B.D.H. alumina (prepared as described in the original paper) or Woelm acid alumina (L. Light & Co. Ltd.). Increasing the amount of alumina and eluting several times with acid did not increase the recoveries : recoveries of catecholamines added to water were,
however, quantitative. Pekkarinen1 notes that there is a substance present in the eluate from urine which inhibits fluorescence. This effect is neutralised by using high dilutions, but this requires a sensitive fluorimeter for measurement. Like Dr. Frazer, I seem to be a slow worker requiring almost two hours for one estimation. Royal Sussex County Hospital, Brighton, 7.
CLIFFORD RILEY.
SIR,—In reply to Dr. Frazer’s comments I should like to give the following information which, to save space, I omitted from the original paper. (1) In preliminary experiments using a fixed volume (200 ml.) of urine it was found that recovery of added catechols varied greatly (as judged by fluorescences obtained), the recovery from more concentrated urines usually being obviously lower. By using an aliquot (1/10) of a 24-hour collection diluted to 200 ml. these variations in recovery were greatly reduced. Since the standard is prepared always from a pooled urine specimen we are concerned only with variations in recovery from urine and comparison with pure noradrenaline standard is irrelevant. (2) Although visual comparison of fluorescence is sometimes difficult, the specificity of adsorption on aluminium oxide at pH 8-5 is such that few interfering substances are present and urines having 2 µg. difference in added noradrenaline (equivalent to 20 µg. per 24 In one or two cases a hours) can be distinguished. blue fluorescence was seen and on these occasions or whenever a comparatively high fluorescence was obtained, the test was repeated including recovery estimations on the urine being tested. (3) The aluminium oxide used (Merck) was dried, after washing and filtering by suction, by spreading on large sheets of filter-paper and leaving overnight in a warm room followed by heating in an oven at 100°C for one hour. As the same batch of aluminium oxide (kept in a stoppered bottle) was always used for unknowns and corresponding standards, variations in adsorptive properties were of no consequence. The results given for urines tested were intended to represent only very approximately the levels of catechols present ; the primary object of the test is to detect amounts in 1.
excess
of 180 ;j!.g. per 24 hours.
Pekkarinen, A., Pitkänen, 1955, 7,1.
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