RETROLENTAL FIBROPLASIA

1128 the existence of the " tail " itself may foster further relative resistance of the gonococcus.

The treatment of gonorrhoea today presents a difficult problem and it was the consensus of opinion amongst participants at Tokyo that the deteriorating situation would tend to continue with increasing numbers of cases and further evidence of lessened sensitivity of the gonococcus to penicillin. There is certainly no place for

complacencv. R. R. WILLCOX. AN EOSINOPHIL COUNTING CHAMBER

SIR,-Ever since the assessment of pituitary and adrenocortical function began to attract increasing attention,

of the

chamber, and I sought

to overcome

the

difficulty by

designing chamber which would completely eliminate contact between drops and air during the counting. In this chamber (figs. 1 and 2) a wall (w) surrounds the ruled area (R) and prevents the drop of fluid in the chamber from coming in contact with air. A support (s) holds the coverglass in contact with the drop. Fig. 3 shows how this chamber eliminates the migration which takes place in other types of chamber. A rectangular ruling (8 X5 mm.), in the Fuchs-Rosenthal pattern, gives large columns for easy reading. It is unnecessary to load the chamber more than once for any particular count. The ruling is divided into fourths by double median lines, thus permitting a count of half or quarter of the ruling in intense eosinophilia. The big volume of the chamber (10 c.mm.) means that the total count gives directly the number of cells per c.mm. of blood, using a dilution of 1 in 10. The shallowness of the chamber (0’25 mm.) overcomes the difficulty of sedimentation so common with deeper chambers. The walls are inclined so that no foreign bodies can stay in it when a

been much controversy about eosinophil New methods and techniques are proposed from time to time, but none seems to solve the problem. It seemed to me that it would be better to concentrate on finding out the reasons for the shortcomings of the well-known acetone methods, which are far superior in their clarity, rather than use fluids whose viscosity and colour make it hard to identify the cells. In spite of the meticulous care of analysts and statisticians, there is still something which confuses results when acetone diluents are used. Fractions of the same blood sample treated by the Dunger, Rud, or other methods, give contradictory results under identical conditions ; and simple experiments showed that even fractions of the same mixture, led simultaneously through pipettes to chambers of various capacity, gave results differing by from 30% to 50%, as the volume of the Fig. 3-Photomicrographs illustrating migration in (a) Jessen chamber (0*4 mm. depth) and (b) Fuchs-Rosenthal chamber (0*2 mm. depth), and absence of chambers was increased.!

there

has

counting.

migration These findings suggested that the trouble lay in the way in which the cells sedimented in the chambers. I found that during sedimentation the peripheral cells were driven towards the centre of the chamber, where cells accumulated, thus seriously affecting the accuracy of the count. In all types of chambers, the periphery was depleted in this way when acetone was used. On the other hand, this phenomenon was not noted in chambers filled with blood and other hsematological fluids not containing acetone. It occurred to me that the cause of this migration (which is a phenomenon distinct .from Poisson distribution) was the contact between air and acetone-containing fluid at the edges ------------

1.

Boghrati, N.

Brux. méd.

1954, 34, 1945, 1999.

in (c) Boghrati chamber

(0*25

mm.

depth).

the chamber is being cleaned. Preparations can be left in the chamber almost indefinitely, and wet boxes are no longer needed. The cells can be coloured in the chamber proper, without risk of desiccation or removal of cells. The distributors of the chamber are Evertex AB, 29, Stortorget, Malmo, Sweden.

N. BOGHRATI. RETROLENTAL FIBROPLASIA

SIR,-Your recent suggestion (April 26, p. 893) to abandon the term " retrolental fibroplasia " and replace " it by " oxygen-induced retinopathy of prematurity may give rise to certain difficulties. "

Fig. I-Photograph

of counting chamber.

For the past four " oxygen-conscious years we have continued to examine the ocular fundi of all infants in the premature nursery of Babies Hospital at weekly intervals. During this period there were 1060 admissions of infants whose birthweight was below 2000 g. Five individuals developed retrolental fibroplasia, a substantially reduced incidence of this distressing condition as compared with four previous years. Three of these infants had experienced only the briefest exposures (minutes) of supplementary oxygen and never in concentrations above 40%. The ocular disease in these infants was in no way different from that observed previously in our nursery in many infants following prolonged exposure to high concentrations of oxygen.

It is important to admit the possibility of the (rare) occurof retrolental fibroplasia as the result of exposure to only atmospheric concentration of oxygen (21%). An accurate history of " no supplemental oxygen " does not exclude the possibility of this disease. The term " oxygen-induced retinopathy of prematurity " may be technically correct and rence

Fig. 2-Longitudinal cross-section.

1129 after exposure use of this term will result in the erroneous exclusion of these cases in future reckonings because of misinterpretation of the limits of this category. Our best ihterests will not be served if retrolental fibroplasia is spuriously eradicated by a glossological

does

not

exclude these

21 oxygen. I

to

am

rare

examples

that

occur

concerned, however, that the

manoeuvre.

Babies Hospital, New York.

WILLIAM A. SILVERMAN.

A FIFTH MALARIA PARASITE OF MAN ?

SIR,-Kindly permit me to make the following observations with regard to your annotationon this subject. Sinton and Mulligan2 made a successful transmission of Plasmodium knowlesi to a monkey with Anopheles annularis and not A. maculipennis as you stated. The following report3 regarding P. knowlesi as a human infection, published in 1952, is also of special interest, since it is based on an attempt at sporozoite-induced transmission, while the other reports, so far as we know, are based on trophozoite-induced transmissions: " Differences in susceptibility of man to sporozoite- and trophozoiteinduced infections of P. knowlesi are also known. Ray (personal communication in 1951) caused three batches of five specimens of A. annularis harbouring sporozoites of P. knowlesi to bite three human volunteers.*"" After biting the human volunteers, each mosquito was dissected and the residual sporozoites were inoculated into three monkeys all of which took the infection. Blood films of the volunteers were examined periodically and not one of them developed the infection in the course of ten months of observation. About the same period, two white mice were inoculated each with two mosquito equivalents of P. knou’Zesi sporozoites, and no infection could be detected in them during two months when their blood smears were examined daily. Man, as already stated, is susceptible to bloodinduced infections of P. krw1t.Zesi but not to sporozoites. White mice on the other hand are not susceptible either to sporozoite- or bloodinduced infections of P. knowlesi." There is

mistake in reference 12: the not Mair.

a

name

of

one

of the

joint authors is Nair and Malaria Institute of India.

***

We

Deputy

Director.

grateful Dr. Ramakrishnan for mistakes.-ED. L.

are

out our two

S. P. RAMAKRISHNAN

Delhi, to

pointing

DEATH OF A BOXER

SIR,-Having spent most of my active sporting life in ring, I feel I should understand both the physiological stresses and the pathological lesions of the art of self-defence. I was lucky in having a precisely developed postman’s knockout punch to win six Irish university titles (1924-29), three British university titles (1927-30), and the heavyweight title of the R.N.V.R. (1931)-all on the

knockouts. None of my opponents ever suffered from any after-effects, and in all my close contact with boxing over thirty-five years I have never seen any permanent lesions caused by it. This great British game teaches a man to stand up and face both physical and moral stresses, which in my own eventful career has stood me well. I foster and admire the noble art, and in this town we have one of the finest boxing clubs in Kent. Of course there are inherent dangers in all sport, as in life in general; but under proper medical supervision and the rules of the A.B.A. and the B.B.B.C., the British bulldos breed, and fair Dlav are fostered. E. F. ST. J. LYBURN.

character,

1. 2. 3.

Lancet, 1957, ii, 932. Sinton, J. A., Mulligan, H. W. Rec. Malar. Surv. India, 1933, 3, 381. Prakash, Satya, Krishnaswami, A. K., Ramakrishnan, S. P. Indian J.

*"

Malar. 1952, 6, 179. One of the volunteers had never experienced any malarial infection at any time while the other two had malaria prior to 1943, 8 years previously, and underwent a radical cure."

TREATMENT OF ASTHMA AND HAYFEVER BY HYPNOSIS SIR,-This correspondence seems to provide data for an observation in what is probably the realm of social psychology or even anthropology: three out of five of your correspondents have either not read the original paper with any attention, or have failed to understand it. Dr. Moynahan (May 17) might not admit this sample of

professional that such

men

as

statistically significant, but

we

feel

of 60% among even a single group is unlikely to be without cause. As one possible interpretation we would point out the emotional affect still apparently a

finding

engendered by the word " hypnotism "-much as it was by " mesmerism in the days of Lavoisier, recalled in Dr. Moynahan’s letter-and the suspicion, or even distortion, of the facts, which such affect can produce in an "

observer. Our object in carrying out the experiment was quite clearly stated in the opening paragraph: noting, with references, the value of hypnosis as a means of symptom relief (not cure) in allergic conditions, we then told how we " tested a patient’s skin reactions to known allergens during the relief of associated allergic symptoms by hypnosis "-and we recorded our results. While endorsing Dr. Moynahan’s views on the education of present-day medical students in statistics and probability theory, we do not, however, believe that all experimental results are necessarily dependent on statistical -analysis-although we admit, incidentally, it often seems that almost any result can be obtained (or refuted) by statistics. In our paper, therefore, we made no " therapeutic claims based on a solitary case " (Dr. Moynahan); " good evidence ... of the value of hypnosis " (Dr. Franklin, May 17) was not presented, since this was taken as read; and we never denied in any way that " individual case-histories can readily be matched ... from patients treated by either psychological or allergic methods." (Dr. Pepys, May 10). Dr. Pepys, in fact, was so busy submitting our report to critical analysis " that he wrote of the "... repeated vigorous skin testing. (10 pricks were made into each site compared with the one prick commonly used for diagnosis.) " From this he then proceeded to draw a whole series of conclusions. The method used, however, was not the " prick test " at all, but the less traumatic and less desensitising technique of " multiple pressure ", with which the other was carefully compared at the outset. Describing our actual tests we wrote: Multiple pressure through the drop was then exerted ten times, without scratching, with a sterile hypodermic needle." Dr. Pepys also suggested that " the inhibition by hypnotic suggestion of a single test on the left leg performed immediately on waking from a deep hypnotic trance, could be attributed to the well-known modification of peripheral circulation by hypnosis ". This, of course, is possible, but if Dr. Pepys consults table i of our paper, he will be able to count no less than 16 positive urticarial reactions recorded as a result of skin testing immediately " on waking from a deep hypnotic trance ". On the one occasion, however, when direct suggestion was made that all skin reactions should be inhibited, there was no reaction on the left leg after testing-and we took this to be "

"

significant.

,

The problem of possible local hyposensitisation raised by Dr. Pepys and subsequently by Dr. Blair Macaulay (May 17) is of more interest and presents one of the inherent difficulties in designing experiments in this field: as does the possible development of an anaphylactoid response when working with other materials. In general it will be found that different parts of the body give different degrees of allergic response to the same allergen when tested at the same time, but that the same part of the