449 in calves given insufficient colostrum their normal growth. The hormone control of milk secretion naturally It received considerable attention at the institute. seems clear that l-thyroxine is as effective as iodinated casein as a stimulant of milk secretion. In the declining stage of lactation its administration gave increased yields up to an extra half-gallon of milk per cow per day, with increases in heart-rates up to 20 beats per minute. The main effect on composition of the milk was to increase the fat and lactose and diminish the protein, but the changes were not great. Experiments have shown that pure anterior-pituitary growth hormone has galactopoietic properties in lactating cows. The previous report from the institute that A.C.T.H. had similar properties has not been confirmed. The bacteriology of milk, cheese, and butter has also been thoroughly studied. Progress reports of herds kept free from Streptococcus agalactiœ illustrate both the difficulties and the possibilities of reducing bovine mastitis in this way. The antibiotic nisin appears to be of considerable value in the treatment of this
diminish or
scouring whey to ensure
infection.
Naturally the institute has many collaborators, a satisfactory number of whom are also engaged in medical research. Indeed, this report might well be quoted as evidence that the distinction between medical and agricultural research is administrative rather than operational. TOUGH TUMOUR CELLS encouraging feature of experimental cancer research is that the control experiments sometimes prove unexpectedly instructive. There is an example of this in the annual report of the Yorkshire Council of the British Empire Cancer Campaign for 1949-50. Prof. R. D. Passey and Dr. L. Dmochowski, of Leeds, describe the control experiments they undertook to repair what in their view was an omission in the work reported by Gye and his colleagues 1 last year, when they showed that mouse sarcomas and carcinomas could still transmit the same type of tumour after being frozen to-79°C and desiccated to powder and subsequently thawed and reconstituted. Passey and Dmochowski confirmed these findings but could not accept the conclusion that, without controls, they necessarily indicated the presence of a virus. Gye et al. held that, judged by appearances, the dryish cells were no longer viable, despite the seemingly intact nuclei in their string-like cytoplasm. At the January meeting of the Pathological Society of Great Britain and Ireland, the Leeds critics recounted how they had dried similar mouse sarcoma tissue under the same conditions and resuspended the cells in diluent, and had now found nothing in the appearances of the cells to suggest that they were not viable. In support of their interpretation-that the cells were the source of transmission of the tumoursPassey and Dmochowski spun the resuspended cells for 3 minutes at 2600-7000 g, which would precipitate cells but not any of the known animal viruses. Thus they brought about a physical separation between diluent, which might contain virus, and cells which might be viable. Deposit and supernatant fluid were next separated and injected into mice. Tumours grew from the cell-containing fraction only. In the discussion at this meeting, R. J. Ludford suggested that any remaining doubt about the viability of the cells might be removed by observing their behaviour in tissue culture. This test, promised in the present report, was subsequently performed with the assistance of I. Glucksmann of the Strangeways Laboratory, Cambridge. At the joint meeting of the pathological societies of this country AN
1.
Gye, W. E. Brit. med. J. 1949, i, 511. Mann, I. Ibid, ii, 251, 253. Gye, W. E., Begg, A. M., Craigie, J., Mann, I. Brit. J. Cancer, 1949, 3, 259.
and Holland, held in Amsterdam in April, photomicroof outgrowing and dividing cells were shown which convinced those who saw them that some of the harshly treated cells had indeed survived and reproduced themselves even in the unfavourable conditions of tissue culture. The original experiments contained their own warning of probable disproof, for dried mammary tumours grew at the point of inoculation in connective tissues of male as well as female mice iri a time interval consonant with cell-grafting rather than with the action of a virus. Four other research centres2 have since reported disagreement with the interpretation of Gye et- al., and it has been shown that when the drying period is slightly prolonged the transmission of tumours fails. Rabbits are proving suitable for testing chemicals that induce bladder cancer. From Sheffield Prof. H. N. Green reports the induction of one ureteric tumour in a rabbit within about 2 years of feeding with acetylaminofluorene. Dr. G. Bonser, in Leeds, has induced one bladder tumour and one ureteric papilloma, besides other changes suggestive of malignancy, within 5 years with the same chemical. She has promising experiments If rabbits respond on hand with betanaphthylamine. to both carcinogens by developing tumours of the urinary tract, this animal will have advantages over the dog in ease of handling and cheapness, though none in point of time. Mice respond only to the first compound and many develop hepatomas as well. The rabbit tumours are limited to the urinary tract.
graphs
-
Statistical inquiries into the inheritance of mammary in this country have yielded no evidence that the incidence was any greater among 584 mothers of patients with this disease than among the same number of unselected women in the general population. This result, checked by the evidence of breast tumours in living daughters and by the death certificates of the mothers, conflicts with observations reported from the Continent which suggest that there is some familial association. Examination of human milk by electron microscopy for evidence of an infective milk agent analogous with Bittner’s agent in mice is proceeding but has not yet reached a reportable stage. cancer
GENERAL PRACTICE IN NORTHERN IRELAND
THE Northern Ireland committee of the Nuffield Hospitals Trust has decided to make an independent survey of the conditions of general practice in the region. The main objects are to improve the status of the general practitioner and to find, if possible, how he can obtain reasonable time for leisure, contact with his colleagues, and postgraduate study. The assumption is that any improvement which can be made on these lines will be reflected in improved service to the patient. Dr. J. A. Fisher, formerly of the Nuffield Department of Clinical Medicine, Oxford, has been appointed to make the survey, which will be based on sample surveys, questionaries, and direct interviews with the practitioners. Although the Nuffield survey is independent, it is being made with the approval and encouragement of the North Ireland Ministry of Health, the Health Services Board, and other interested authorities in the region.
Provincial
THE INDEX and title-page to Vol. I, 1950, which was completed with THE LANCET of June 24, is now in preparation. A copy will be sent gratis to subscribers on receipt of a postcard addressed to the Manager of
THE LANCET, 7, Adam Street, Adelphi, W.C.2. Subscribers who have not already indicated their desire to receive indexes regularly as published should do so now.
2. British
Empire Cancer Campaign, Annual Report for 1949-50.