437

In two other patients with the same syndrome, the sustainedhigh osmolality of the urine was significantly lowered by theadministration of ethacrynic acid, a new diuretic affecting theconcentrating mechanism of the kidney.

R. C. DE SOUSA

J. DELAERE.

B. BERDE.

Clinique Universitaire de Thérapeutique,Hôpital Cantonal, Geneva, Switzerland.

Medizinisch-BiologischeForschungs-laboratorien, Sandoz, A.G.,

Basle, Switzerland.

TITLES OF ARTICLES IN MEDICAL PERIODICALS

C. E. D. TAYLOR.Diagnostic Reference Laboratory,Central Public Health Laboratory,Colindale Avenue, London, N.W.9.

SIR The titles of articles in medical periodicals arenot always as meaningful as they might be. Most readershave to be selective in what they read, and selection ispossible only when titles give some indication of what thearticles are about.

In The Lancet of Feb. 6 there appeared a leading articleentitled " Akufo and Ibarapa ". If the title of this hadbeen for example

" Health of African Communities ", notonly would it have been possible to decide whether thesubject was relevant to the individual reader, but subse-quent indexing and filing would have been much easier.The advice given by Bett 1 in this context is worth

quoting:" A good title means a lot to the success of your paper. It

should be short, yet sufficiently descriptive. Above all, itshould promise interest and thus be attractive, even catching.But don’t make it too paradoxical, obscure, or misleading."

Diagnostic Reference Laboratory,Central Public Health Laboratory, C. E. D TAYLOR.Colindale Avenue, London, N.W.9. C. E. D. TAYLOR.

Perhaps we should try to be as coldly descriptive asDr. Taylor suggests-but we promise to relapse fromtime to time. After all, Dr. Bett’s excellent advice neednot apply so strictly to the short editorial article, whosetheme can be picked out in a glance or two, howeverinscrutable the title. Our illusion is that Akufo and

Ibarapa does more than Health of African Communitiesto persuade people to look at (and even read) what we aresaying.-ED. L.

SEASON AND TERATOLOGY

SIR,-A preliminary review of the results of a terato-logical investigation on mice, carried out with small dosesof ionising radiation as the teratological agent, seems tosuggest a certain variation in the susceptibility to radiationas regards induction of resorption and litter-size. Thisfeature does not seem to have been observed previouslyin the analysis of the results where weak teratogens areconcerned.

On the eighth day of pregnancy, groups of pregnant femalemice of the HC strain were exposed to whole-body X-irradiationwith doses of 5r, 20r, and 100r. The number of foetal

anlages irradiated is indicated in the accompanying table. Thenumber of young and the number of resorptions were registeredimmediately before the anticipated delivery. Where thesummer group was concerned, conception occurred betweenApril 1 and Sept. 30, and for the winter group between Oct. 1and March 31.

It appears from the table that after irradiation, even with 5r,there is a higher percentage of resorptions, while as regardslitter-size a definite effect was only observed at a dosage of100r. As regards both the incidence of resorption and litter-size, however, there is a seasonal difference. This may suggestthat the teratogenic agent unmasks a latent seasonal variation,which becomes more apparent by a greater irradiation effect inwinter.

In the 5r group the difference between the incidences ofresorption is statistically significant at the 5% level. The

1. Bett, W. R. The Preparation and Writing of Medical Papers for Publi-cation; p.14. London, 1953.

TABLE I-INCIDENCE OF RESORPTION AND LITTER-SIZE, DISTRIBUTED INRELATION TO DOSE AND SEASON

seasonal variations in the other experimental groups all showthe same tendency but are not statistically significant. If allirradiated mice are combined, the difference between the

frequency of resorptions in the summer and the winter groupsis very highly significant (0002 > p > 0.001).

Further examination of a possible seasonal influence onpathoembryological processes is therefore desirable. Thepresent findings indicate that season of birth should beconsidered in teratological studies when experimental andcontrol groups are compared.

LARS JACOBSEN.

University Institute ofMedical Genetics,

14, Tagensvej, Copenhagen N,Denmark.

HAGEMAN FACTOR IN THE FIBRINOLYTIC

SYSTEM

SIR,—The role of Hageman factor (H.F.) (factor XII) infibrinolysis is not yet clear. Some workers 1—6 have

suggested that it has fibrinolytic activity, but others cannotconfirm this.’ 8 Iatridis and Ferguson 4 believe that H.F.activates intrinsic proactivator (" proplasminoplasmin

"

in their terminology). Aznar et al.2 9 confirm this, butsuggest that, in addition, H.F. directly activates plasmino-gen. Schoenmakers et al. initially could not demonstratea fibrinolytic activity of H.F., but later, using a purifiedfraction, they presented evidence which also suggested thatH.F. is an activator of plasminogen.1oWe report here further studies of the role of H.F. in the

generation of plasmin.Crude H.F. was prepared by shaking plasma obtained by the

" silicone technique ", with 30 mg. of celite powder per ml.plasma. H.F. was eluted from the powder with isotonic salinesolution at pH 10-5. The eluate contained no other clottingfactor activity except P.T.A. (factor XI),1 which is known to beinactive in fibrinolysis.11 The eluate contained 03-04 mg. ofprotein per ml.

In the first experiment, one drop of the H.F. eluate wasincubated for 24 hours at 37°C (986°F) on an unheated fibrinplate. 100 determinations performed in this way yielded areasof lysis with diameters of 7-15 mm. 50 determinations were

performed using the same H.F. eluate but a heated fibrin plate.No lysis was observed in 43 determinations. Slight areas oflysis, probably due to residual plasminogen in the plates, were1. Aznar, J., Lopez-Borrasca, A., Calatayud, R., Barata, J. J. Rev. clin.

esp. 1963, 89, 276.2. Aznar, J. Thesis, 1964.3. Iatridis, S. G., Ferguson, J. H. Thrombos. Diathes. hœmorrh., Stuttg.

1961, 6, 411.4. Iatridis, S. G., Ferguson, J. H. J. clin. Invest. 1962, 41, 1277.5. Niewiarowski, S., Prou-Wartelle, O. Thrombos. Diathes. hœmorrh., Stuttg.

1959, 3, 593.6. Niewiarowski, S., Stachurska, J., Wegrzynowicz, Z. ibid. 1962, 7, 514.7. Ratnoff, O. D., Crum, J. D. J. Lab. clin. Med. 1964, 63, 359.8. Schoenmakers, J. G. G., Kurstjens, R. M., Haanen, C., Zilliken, F.

Thrombos. Diathes. hœmorrh., Stuttg. 1963, 9, 546.9. Aznar, J., Santiago, E., Macarulla, J. M. Rev. esp. Fisiol. (in the press).

10. Haanen, C., Schoenmakers, J. G. G., Morselt, G. E. Xth CongressInternational Society of Hæmatology, Stockholm, August, 1964.

11. Aznar, J. Rev. esp. Fisiol. 1964, 20, 43.