363 12 has been related to the level of inducibility ofA.H.H. in individuals, which is genetically controlled.13 Continuous exposure of a population to such a potent inducer of an enzyme known to catalyse these reactions carries evident risks. Whilst alarm should not be raised prematurely, in this country T.C.D.D. is produced as a contaminant in the commercial production of trichlorophenol, and it would be as well if these facts were known in the tragic and, we are assured, un-

comas"

likely event of an accident at the manufacturing plant. Cytogenetics Unit, Nuffield Wing, School of Medicine, P.O. Box 147, Liverpool L69 3BX

C. D. DEWSE

*,* An editorial on T.C.D.D. appeared 297).-ED. L.

in

our

issue of Aug. 7

(p.

CULTURE OF M. LEPRÆ WITH HELP OF DESICCATED THYROID i

Plasma-paracetamol estimation: correlation between kit and Glynn methods.

SIR,—Following Biswas’s suggestion14 we have tried to cultiMycobacterium leprce on medium supplemented with extract of desiccated thyroid gland. The material for culture was taken from a 16-year-old Zairian boy admitted to the Uni-

vate

versity in a fume cupboard. T.C.A. should not be used in a ward situation by untrained staff. Leakage of serum from the filter assembly also poses a health risk. The main hazard to the patient would appear to be that patients with mild overdoses mav be given treatment with cysteamine-which may be accompanied by severe side-effects. Prescott et al.5 have indicated that such treatment should only be used where a severe overdose has been demonstrated. We cannot recommend the use of the kit by nursing and medical staff in emergency units. Department of Biochemical Medicine, M. J. STEWART Ninewells Hospital and Medical School, Dundee DD2 1UD JOHN E. BARCLAY

ferably

,

Clinic

at

Lubumbashi

on

March

11, 1976.

A clinical

diagnosis of lepromatous leprosy was confirmed by direct microscopic examination of nasal smears (Ziehl-Nielsen) and by biopsy of a non-ulcerated nodule from the patient’s forearm (Prof. R. Parmentier, Brussels). Direct smears were also done on biopsy material from an ulcerated nodule and stained with Gram and Ziehl methods. Acid-fast organisms, morphologi-

DANGERS OF T.C.D.D.

SIR,—The full import of the accidental release of 2,3,7,8tetrachlorodibenzo-p-dioxin (T.C.D.D.) in the Seveso region of Italy has not been publicised in the press reports, possibly to avoid panic. Whereas early precautionary evacuation of women

and children

was

carried

out

and

a

strong

dation

recommen-

against procreation was circulated on grounds compound’s known teratogenic properties, surely an

of the imme-

diate full-scale evacuation of the area was warranted. T.C.D.D. has been shown to be some 30 000 times more potent an inducer of the enzyme aryl hydrocarbon hydroxylase ,.H.H.’ than 3-methylcholanthrene (M.c.) in rat liver,6 and is some 40-60 times more potent than M.c. as an inducer of .H.H. in cultured human lymphocytes.’ A.H.H. is strongly imphcated in chemical carcinogenesis8 in that many chemically non-reactive carcinogens--e.g., polycyclic hydrocarbonsbe metabolised by cellular enzymes to produce biological âfects such as carcinogenesis.9 Further, incidence of human bronchogenic carcinomas1o and of M.c.-induced mouse sarI

5 Prescott, L F., Swainson, C. P., Forrest, A. R. W., Newton, R. W., Whright, N, Matthew, H. ibid. 1974, i, 558. 6 Poland, A. P, Glover, E Mol. Pharmacol. 1974, 10, 349. 7 Kouri, R. E., Ratrie, H. III, Atlas, S. A., Niwa, A., Nebert, D. W. Life

Sciences, 1974, 15, 1585. 8 Heidelberg, C Ann. Rev. Biochem. 1975, 44, 79. 9 Marguardt, H., Sodergren, J. E., Sims, P., Grover,

P. L. Int. J. Cancer, 1974,13,304. 10 Kellermann, G., Shaw, C. R., Lutyen-Kellermann, M. New Engl. J. Med. 1973, 289, 934.

Culture of M. leprœ on medium enriched with desiccated showing also the Blastomyces.

Circles indicate M.

thyroid gland,

leprae in globi.

cally indistinguishable from M. leprce, blue-stained spores, and mycelia of Blastomyces and staphylococci were seen. The acidfast bacilli were grouped in clumps (globi) or separated, some of them adherent to the mycelium and terminal spores. Biopsy material was inoculated on two sorts of Sabouraud mediumone with penicillin and streptomycin only, the other with these antibiotics and desiccated thyroid. After 5 days colonies had grown on the two Sabouraud media and the staining with 11. Kouri, R. E.,

Salerno, R. A., Whitmire, C. E. J. natn. Cancer Inst. 1973, 50, 363. 12. Koun, R. E., Ratrie, H. III, Whitmire, C. E. Int. J. Cancer, 1975, 11, 714. 13. Kellermann, G., Lutyen-Kellermann, M., Shaw, C. R. Am. J. hum Genet. 1973, 25, 327. 14. Biswas, S.K. Lancet, 1975, ii, 716.

Letter: Dangers of T.C.D.D.

363 12 has been related to the level of inducibility ofA.H.H. in individuals, which is genetically controlled.13 Continuous exposure of a population t...
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