747

A COMPOUND WHICH LOWERS BLOOD-UREAIN URÆMIC DIABETES

M. J. PHILLIPS.R.A.F. Hospital,

Changi, Singapore.

SIR,-Professor Butterfield and his colleagues (Aug. 16,p. 381) raise many interesting points in their report on theblood-urea-lowering effect of y-guanidinobutyramide.Their initial observations do not suggest that an increase inthe renal clearance of urea is the cause of the fall in blood-urea. They intimate that the drug may exert its effect byinfluencing the Krebs-Henseleit cycle, presumably byblocking a specific step in the synthesis of urea or bygenerally inhibiting the metabolism of appropriate amino-acids. I should like to offer another possible explanation ofthe compound’s effect-namely, the diversion of urea fromthe plasma to other fluid spaces.The observations of Blackmore and Elder 1 and Shackman

et al.2 on urea distribution in renal failure may be relevantto the action of y-guanidinobutyramide in lowering blood-urea. These workers showed that urea is not always freelydiffusible throughout the total body water. They contendedthat urea might, under certain circumstances, exist indiffusible and non-diffusible (bound) forms. Blackmore andElder 1 demonstrated that erythrocyte water urea levels wereraised higher than plasma-urea levels in patients with renalfailure due to trauma and glomerulonephritis. The precisemechanisms where by urea may be preferentially boundwithin cells are not known. It has been shown to combinewith haem,3 hxmoglobin,4 and sodium desoxyribonucleate.5Blackmore and Elder 6have also suggested that the non-diffusible component of urea may be bound to protein orlipoprotein in the cell membrane. It is not beyond thebounds of possibility that a substance which can lowerblood-urea without increasing the renal clearance of ureacould exert this effect by altering the distribution of ureabetween the plasma and the intracellular space-i.e., byproducing a diffusible/non-diffusible urea gradient.Although it is more likely that y-guanidinobutyramide

will be found to influence the metabolism of aminoacids,Professor Butterfield and his coworkers may like to con-

sider, at this early stage of their investigations, measuring thecorresponding levels of plasma and erythrocyte water urea.

TOPICAL TREATMENT OF BURNS

P. A. P. POMPAMedical Adviser.

Pharmax Ltd.,Dartford, Kent.

SIR,-In your annotation on this subject (Sept. 20,p. 629) you state that " Before the introduction of genta-micin treatment the mortality for pseudomonas toxaemiaand septicaemia was 100% ". However, in 1963, Speirset al. were confronted with a case of pseudomonas septi-caemia in the presence of congenital hypogammaglobinaemia.The patient was successfully treated with colistin sul-phomethate sodium, with complete elimination of the

organism from the bloodstream. In 1964, Murdoch 8

successfully treated six out of eight patients with pseudo-monas septicaemia using colistin therapy. The two patientswho died were moribund at the time of treatment. And in

1966, Jones et al. 9 carried out a pilot study with colistin inthe treatment of ten patients with pseudomonas septicaemia

1. Blackmore, D. J., Elder, W. J. J. clin. Path. 1961, 14, 455.2. Shackman, R., Chisholm, G. D., Holden, A. J., Piggot, R. W.

Br. med. J. 1962, ii, 355.3. Burk, N. F., Greenburg, D. M. J. biol. Chem. 1930, 37, 197.4. Murdaugh, H. V., Doyle, E. M. J. Lab. clin. Med. 1961, 57, 759.5. Ruffo, A., Santamaria, R., Matlace-Raso, F. Boll. Soc. ital. Biol.

sper. 1955, 31, 1381.6. Blackmore, D. J., Elder, W. J. Proc. II int. Congr. Nephrol. p. 387.

Prague, 1963.7. Speirs, C. F., Selwyn, S., Nicholson, D. N. Lancet, 1963, ii, 710.8. Murdoch, J. McC. Proc. III int. Congr. Chemother. p. 319. Stuttgart,

1963.9. Jones, R. J., Jackson, D. McG., Lowbury, E. J. L. Br. J. plast. Surg.

1966, 19, 43.

associated with infected burns. Three patients receivedvery high doses of colistin sulphomethate sodium (up to25 megaunits daily). Of the four patients who survivedall had received a course of colistin, while only two of thesix who died had received such a course. Five of thosewho died were, however, moribund when the diagnosis ofsepticxmia was made.These three references alone illustrate that colistin was

effective in reducing the mortality from pseudomonassepticaemia as early as 1963-before the emergence ofgentamicin.

THE EFFECT OF NEURAMINIDASE ONLYMPHOCYTE CULTURES

H. KIRCHNER.

Hämatologische Abteilung,Klinikum Steglitz der Freien Universitat,

Berlin.

SIR,-Caron has shown that the spontaneous trans-

formation-rate of human peripheral-blood lymphocytes inculture is 0-08% on the sixth day of culture. We ourselveshave never found a higher blastic index in untreatedcultures; and this prompts us to report some preliminaryfindings on the influence of neuraminidase on normal

peripheral lymphocytes in vitro.Our technique was as follows. Heparinised blood from

healthy volunteers was allowed to settle for 60 minutes, andthe leucocyte-rich supernatant was then withdrawn. Thecultures were composed of 1 ml. of cell suspension(containing 2-4 million cells), 1 ml. of autologous plasma,and 4 ml. of 1’c 199 medium with added penicillin (100 l.u.per ml.) and streptomycin (100 ug. per ml.). After 144 hoursthe cultures were centrifuged, and the cells stained withPappenheim stain and with acridine-orange. 2 By thesemethods the blastic lymphocytes could easily be distin-guished from macrophages.3Using this technique we have investigated the effect of

neuraminidase (0’1 ml. a-neuraminidase prepared fromVibrio cholerae in 0-05M acetate buffer), which was addedwhen the cultures were set up. 10 cultures from 5 differentdonors were treated with neuraminidase, and these werecompared with untreated control cultures. The blastic

response was always less than 1 per 2000 in the controls, butin 7 of the treated cultures it ranged from 1-2 to 3’1%.The remaining 3 cultures seemed to be unaffected.

Several agents cause blastic transformation in lympho-cytes,4-13 but the reasons for the stimulation are far fromclear. Neuraminidase, an enzyme which has formerly beenused in the investigation of cell surfaces,14,15 may throwsome light on this phenomenon. We are now trying to findout why some of the cultures were not affected by theenzyme. There is some evidence that the culture con-ditions, rather than the properties of the cells, were

responsible.The neuraminidase was supplied bv Serva, Heidelberg.

1. Caron, G. A. Br. J. Hœmat. 1969, 16, 313.2. Schiffer, L. L. Blood, 1962, 19, 200.3. Brücher, H., Dill, A., Gräber, M. Acta hœmat. 1969, 41, 76.4. Nowell, P. C. Cancer Res. 1960, 20, 462.5. Barker, B. E., Fames, P., Fanger, H. Lancet, 1965, i, 170.6. Pearmain, G., Lycette, R. R., Fitzgerald, P. H. ibid. 1963, i, 637.7. Schreck, R. Am. Rev. resp. Dis. 1963, 87, 734.8. Gräsbeck, R., Nordman, C., de la Chapelle, A. Lancet, 1963, ii, 385.9. Oppenheim, J. J., Rogentine, G. N., Terry, W. D. Immunology,

1969, 16, 123.10. Bain, B., Vas, M. R. Lowenstein, L. Blood, 1964, 23, 108.11. Mazzei, D., Novi, C., Bazzi, C. Lancet, 1966, ii, 232.12. Mazzei, D., Novi, C., Bazzi, C. ibid. p. 802.13. Turk, A., Glade, P. R., Chessin, L. N. Blood, 1969, 33, 329.14. Langley, O. K., Ambrose, E. J. Biochem. J. 1967, 102, 367.15. Woodruff, J. D., Gesner, B. M. J. exp. Med. 1969, 129, 551.