TOTAL COLOUR-BLINDNESS

640

ANNOTATIONS SHIPS AS HOUSES

DURING the lifetime of most of us, as Dr. J. Greenwood Wilson remarks on another page, the State has regarded the ship as a house for public health purposes, and the port sanitary authority at which the ship calls is responsible for hygiene at sea in the same way as the land sanitary authority is responsible for domestic hygiene. Nevertheless, while the standard of housing has steadily gone up, the standard of the forecastle is not much different from what it was 20 or 30 years ago, and Dr. W. F. Dearden is not alone in attributing the undue sickness among sailors to conditions mainly created by faulty situation and bad structural arrangement. Inspector Mackie, in Dr. C. F. White’s recent report for the Port of London, says that British tramp ships still compare badly with ships of other nations in having an old type of forecastle, devoid of the facilities which would encourage a sanitary standard of living. It is now generally admitted that accommodation in the bows of a cargo ship is unsatisfactory. The crew should be in the poop or amidships. And it is easy to think that, if the medical care of seamen had been in the hands of the Ministry of Health instead of the Board of Trade, the improvement of ships and houses would have gone along parallel. Dr. White himself believes that things are improving. The shipping industry has been very sick and the convalescent must not be called upon for effort beyond his strength. It is not true that all owners are hard, all officers slack, and all sailors dirty. But how easy it is for a vicious circle to be started : poor accommodation in which only men who are indifferent to comfort and cleanliness will sail; disheartened officers who cease to endeavour to maintain decent conditions ; owners who regard it as a waste of money to provide good quarters because they are not properly cared for by the occupants. If only one of the many recommendations made last year by the Association of Port Sanitary Authorities was accepted, things would soon be different. It is so modest a recommendation that it could be put into force at once. In plans for new ships let the accommodation to be provided for officers and crews be approved by a committee of which one or more members is a medical sanitarian with a special knowledge of marine hygiene. The recommendation was first made fourteen years ago, and its fulfilment must not tarry.

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meability of the vessel walls to plasma proteins, could be successfully treated with " vitapric" but not with pure ascorbic acid. Vitapric is an impure concentrate of ascorbic acid prepared from Hungarian red pepper. The inference seemed clear that the activity of this concentrate could not be due to ascorbic acid itself but must be due to an impurity. An attempt was made to concentrate an active fraction, and lemon juice was selected as starting material. After a series of chemical manipulations, including two precipitations with lead acetate and a final treatment with alcoholic baryta, a substance was obtained which appeared to be an almost pure flavon glucoside. It crystallised in pale yellow needles and was called citrin (citrus flavon), or, rather regrettably, vitamin P. It is not clear why it should be thought necessary to give a vitamin lettering to a substance whose position is known and to which a name can be given. Citrin proved able to decrease the permeability of the vascular wall, in cases of the type mentioned above, when injected in daily amounts of 40 mg., equivalent to 200 c.cm. of fresh lemon juice. Its action was not long maintained, and the permeability increased again quickly when the administration was discontinued ; but its effect on the general condition, when administered continuously for a long time, remains to be determined. Cases of the right type for study are scarce, and no satisfactory animal test has yet been devised, so that progress in the field may be slow. Experiments to ascertain whether citrin has a specific action or whether other flavons are also effective have not given a definite result, but two such substances, quercitrin and rhamnetin, which were also tested, differed from citrin in causing fever and collapse when injected, and the result was thus obscured. The flavon, citrin, should be clearly distinguished in name from the other group of yellow dyes called flavins, and in function from the fat-soluble substance called vitamin T 3, which is supposed to have a favourable action in Werlhof’s disease (thrombo-

cytopenic purpura) by promoting thrombocytosis. TOTAL COLOUR-BLINDNESS

CONGENITAL total colour-blindness is very rare; indeed Julia Bell, for her monograph on colourblindness,4 could find records of only 119 cases. In recording a further case in our present issue Dr. Macgillivray and Dr. Macleod point out that all colours are differentiated by their light and shade only, FLAVON AND CAPILLARY PERMEABILITY other typical symptoms being amblyopia, photophobia, nystagmus, shortening of the red end of THERE are a great many substances produced by the vegetable kingdom whose use to the plant we the visible spectrum, displacement of the brightest do not know, but which have been found indispensable part of the spectrum from the yellow towards the green, and the frequent presence of central scotomata to the discharge of some function, or the prevention of in the fields of vision. These cases therefore are some pathological state, in the animal which eats them. Flavon is now added to the substances of this kind, for essentially different from those of partial colour-blindin which most of the Szent-Gyorgyi and his colleagues at Szeged announce ness, which are common and are absent. The ordinary accompanying symptoms that fiavon from plant tissues has a specific action in the human body in influencing the permeability colour-blind person may pass through life without of the walls of the blood-vessels.122 Some of the knowing of his defect unless tested for certain special It would be almost impossible for the of Hungarian workers had found that cases of purposes. group " of total colour-blindness to do this. The subject non-thrombocytopenic " p-uxpura with increased of the condition is unknown, and it is pathology of the permeability capillary walls to whole blood, entirely a matter of speculation whether the abnorand cases of septic infection with increased permality is primarily an affection of the retina or of and A. : Szent-Györgyi, Nature, 1936, 1 Rusznyák, St., -

cxxxviii., 27. 2 Armentano, L., Bentsáth, A., Béres, T., Rusznyák, St., and Szent-Györgyi, A.: Deut. med. Woch., August 14th, 1936, p. 1325.

3 Schiff, E., and Hirschberger, C.: Jahrb. f. Kinderheilk., 1936, cxlvi., 181, 191, 293. 4 Eugenics Laboratory Memoirs, vol. ii., Part 2. London, 1926.

641 the brain. Miss Bell could find records of only two cases in which it was confined to one eye and these If they are excluded the theory that were doubtful. the primary fault lies in the structure of the foveal cones seems highly improbable. On the other hand, there is nothing but conjecture to support the theory that the fault lies in the visual centres in the brain. In some respects the total colour-blindness is analogous to albinism in which defects of the retinal structure have also been held responsible. In four cases of albinism in which a microscopical search has been made the fovea has been found to be structurally

defective. The occurrence of multiple cases in the same families places the hereditary nature of total colourblindness beyond a doubt, but the mode of inheritance is unknown. Direct inheritance has not been noted ; on the other hand, consanguinity in the parents of affected stocks has. Ordinary (partial) colour-blindness is evident in some of the pedigrees, but this condition is so common in the population at large that the connexion may be merely accidental. AIR-BORNE THREADWORM INFECTION

IN discussing whether ascaris infection may be air-borne we have pointed outthat the question needs an answer not only because of its importance in ascaris infection, but because its bearing on infection with Cysticercus cellulosce and possibly with other parasites. Confirmation of the last suggestion has come from F. A. Lentze2 working with Enterobius vermicula7is, the common threadworm of£ man. As is well known, the female worm ofthis species creeps out of the anus for oviposition, and seems never to get back. While it is outside the anus its wrigglings cause irritation ; the parts are scratched and in this way, it is generally believed, the eggs get under the finger nails, are carried by them to the mouth, and are swallowed. Prevention will then depend on keeping the hands away from the anus, particularly by making children wear closed combinations at night and by many scrupulous washings. But Lentze has been dissatisfied with this explanation, because when all these precautions were taken infection still went on. He noted too that for the worm’s development from the egg it was necessary that it should pass six hours in an acid medium. That being so there is no room for the suggestion of G. Penso3 that there is a stage in the worm’s life in which it makes use of the mucosa of the large intestine as a sort of intermediate host, and Lentze Either the female was left with the two possibilities. worm at some time alters its instinct for passage down the bowel to one for passage up it to a level near the stomach where the reaction is acid and that after oviposition eggs stay there for six hours ; or infection may be air-borne. The first alternative being biologically unlikely he tested the second. His earlier work had shown that threadworm eggs are able to pass through any material which is not so he smeared a piece of nightshirt it put in the upper 10 cm. ofa wide cardboard cylinder 80 cm. long with open ends, shook this at the level of his head and then set it vertically on a glass plate, at the same time covering the upper end after taking away the cloth. The glass plates were replaced by fresh ones at frequent intervals, and eggs were first found on them two minutes after the infected cloth had been taken away; in addition

closely

woven,

with eggs,

1 THE LANCET, 1935, ii., 313. Zent. f. Bakt. (Abt. i.). 1935, cxxxv., 156. 3 Policlinico (Sez. Prat.), 1935, xlii., 1943, 1949. 2

Lentze found two eggs in the washings from his nose. Eggs had been carried by air for a distance of at least 70 cm. in conditions which had a physical likeness to those present when air currents are caused by restless movements under bedclothes. Lentze’s suggestion is that eggs reaching the nose in this way are caught up there and pass to the stomach by being swallowed, or that the larva hatches out and passes actively down the oesophagus to the stomach. There is, however, a third possibility when a larva has hatched out in the air-passages-namely, that it, like other nematode larve, bores into the mucosa, enters a blood-vessel and gets carried by the circulatory and respiratory escalators to the oesophagus, to be then swallowed. Whether there is a passage of infected material from the respiratory mucosa to the stomach, and if so in what manner it takes place, is at present only reasonable conjecture ; but what Lentze has shown is that threadworm eggs have in fact been carried to man by air. It becomes increasingly clear that the air is the vehicle concerned in the spread of certain worm infections, and even the helminthologist will be wise to become air-minded. As a practical point in treatment Lentze is satisfied that the usual anal ointments are soothing because they keep the wriggling worms from touching and tickling the skin, but that they actually make easier their escape from the bowel and the start of fresh infection. PROGESTIN AND UTERINE CONTRACTIONS

THE efficacy of corpus luteum extracts in cases of habitual abortion for whichno organic cause can be found was discussed in these columns not long ago.l There seems little doubt that this condition is often due to abnormal irritability of the uterine muscle during the early months of pregnancy before the foetus is securely anchored by a fully developed placenta. For purposes of treatment the natural product prepared from the corpora lutea of sows has been chiefly used, but Kane2 now claims a higher proportion of successes with a synthetic preparation, possibly because this contains no oestrogenic material. He also reports abortions in subsequent pregnancies in which no corpus luteum was given-an observation showing the necessity for treatment in each succeeding pregnancy. But this, of course, is only what might be expected, since the administration of corpus luteum extract is merely a form of replacement therapy, and-apart from the possible influence of maternity in improving sexual function-has no permanent effect on the inherent defect, which is a relative lack or premature withdrawal of progestin during the early months of In his series of 36 successful cases pregnancy. 3 of the infants were born with some congenital abnormality, such as a spina bifida or an imperforate It is improbable that such congenital defects anus. are due to the influence of the artificially administered progestin, and they may rather be attributed to the fact that abortion is sometimes nature’s method of eliminating the unfit. Several investigators have shown that a relatively high proportion of aborted foetuses have anatomical abnormalities. The tonic contraction and retraction of the involuting uterus is a mechanism that tends to disappear in multiparse and give place to spasmodic, imbalanced, and painful uterine contractions known as after-pains. Lubin and Clarke,3 in a series of 2 Kane,

1 THE LANCET, 1936, i., 728. H. F.: Amer. Jour. Obst. and Gyn., July, 1936, 3 Lubin, S., and Clarke, F. J. : Ibid., p. 134.

p. 110.