610

We thank Prof. J. E. Banatvala and members of his staff at StThomas’ Hospital and Medical School, London, who kindly demon-strated their technique to us.

Department of Microbiology,Bedford General Hospital, (North Wing)Bedford MK40 2NU

L. M. DE SILVA

J. MARSHALL

HLA-B27 IN BLACK PATIENTS WITH ANKYLOSINGSPONDYLITIS

SIR,—The strong association between ankylosing spondy-litis (A.s.) and HLA-B27’-3 is commonly used in clinical diag-nosis and family counselling,4 but its usefulness in AmericanBlacks has been questioned.’ To evaluate this issue, we testedsera from 89 patients with "rheumatoid-type" complaints forHLA-B27. Diagnostic categories were assigned in accordance

INCIDENCE OF HLA-B27 ANTIGEN IN BLACK AND WHITE PATIENTSWITH POSSIBLE A.S.

with standard criteria and independently of HLA typing.HLA antigens were determined by a standard microcytotoxi-city technique.?The data are presented in the table. All Whites, both male

and female, with A.S. were B27 positive, but only half theBlack patients with A.S. were B27 positive (P<0.001). No otherHLA/A or B antigen was common to the B27-negative pa-tients.

These data confirm the findings of Khan et al. Cautionmust be exercised in utilising HLA typing as a diagnostic aidin Black patients, particularly when counselling B27-negativerelatives.

Divisions of Orthopedic Surgeryand Immunology,

Duke University Medical Center,Durham, North Carolina 27710, U.S.A.

ROBERT J. RUDERMANFRANCES E. WARD

NUCLEAR TUBULOFDLAMENTOUS INCLUSIONS INVIPOMAS

SIR,&mdash;We have studied by electron microscopy three cases ofVerner-Morrison syndrome with vasoactive intestinal peptide(v.i.p.) secreting tumours of the pancreatic islets. The hormonewas identified by extraction or immunofluorescence methods.

At the ultrastructural level, the cellular proliferation couldbe classified as Dl-cells. The small (150-250 nm) secretorygranules appeared round with a dense core and a tightly fittinglimiting membrane. Some nuclei lodged tubulofilamentous in-clusions, formed by parallel microfilaments crossed by regu-

1. Brewerton, D. A., Caffrey, M., Hart, F. D., Nicholls, A., Sturrock, R. D.Lancet, 1973, i, 904.

2. Schlosstein, L., Terasaki, P. I., Bluestone, R., Pearson, C. M. New Engl. J.Med. 1973, 288, 704.

3. Ryder, L. P., Svejgaard, A. Associations Between HLA and Disease: reportfrom the HLA and Disease Registry. Copenhagen, 1976.

4. Ritzmann, S. E. J. Am. med. Ass. 1976, 236, 2305.5. Khan, M. A., Braun, W. D., Kushner, I., Steinberg, A. G. in HLA and

Disease; abstr. p. 40. INSERM, Paris, 1976.6. Bennett, P. H., Wood, P. H. N. (editors). Population Studies of the Rheu-

matic Diseases (Excerpta med. int. Congr. Ser. 1976, no. 148).7. Amos, B., Cabrera, G., Bias, W. B., MacQueen, J. M., Lancaster, S. L.,

Southworth, J. G., Ward, F. E. in Histocompatibility Testing 1970

(edited by P. I. Terasaki); p. 259. Copenhagen, 1970.

Intranuclear rod in Dl-like tumour cell.

(Reduced to about half of x 13 500.)

larly spaced electron-dense material. Their maximum lengthwas 5900 nm.The same nuclear rods have been seen in sympathetic

neurons of cats,’ and Bryant et al. have demonstrated v.Lp.secretion by sympathetic tumours (ganglioneuroblastomas).

Our findings accord with a neural origin for endocrine pan-creatic cells.

Department of Pathology,H&ocirc;pital Lariboisi&egrave;re,Paris 75010, France

U. 56 INSERM, Bic&ecirc;tre

J. P. LECLERC

J. M. SCOTTO

1. Seite, R., Escaig, J., Couineau, S. J. ultrastruct. Res. 1971, 37, 449.2. Bryant, M. G., Bloom, S. R., Polak, J. M., Albuquerque, R. M., Modlin, I.,

Pearse, A. G. E. Lancet, 1976, i, 991.

Commentary from Westminster

FROM A CORRESPONDENT

Clause 49 of the Patent Bill

RELATIONS between the Government and the phama-ceutical industry seem a little strained at the momentbecause of a fierce tussle which has been going onbehind the scenes over price control. The Government isseeking to re-enact the controversial provision allowinglicences for new drugs to be made available to competingfirms who took no part in the original research. The aimis to stimulate price competition and restrain highprices. But it is a provision which has been universallyhated by the industry since it first became law in the Pa-tent Act 1949.

Last week Conservative peers rode to the industry’srescue when they removed from the new Patent Billclause 49 re-enacting section 41 of the old legislation.Against the advice of the Lord Chancellor the Housedecided by 78 votes to 45 to throw out the clause. LordElwyn Jones had warned peers that by deleting this pro-vision they could be prejudicing talks going on betweenthe Government and the industry to try and reach avoluntary agreement. The Government now has to

decide whether to try and put clause 49 back into theBill when the legislation comes to the Commons. With-out an overall majority this could be difficult. Much willdepend on whether the industry agrees to the voluntaryarrangements which have been put to it.