- Email: [email protected]
TRI-IODOTHYRONINE DETERMINATIONS IN URINE
101 contribution of the cation is
to
promote conformational
changes.2 It is postulated that under the conditions employed, preferential reversible A-T thermal denaturation occurs at the same time as caesium is complexing with G-c nucleoprotein. In the staining solution, the A-T instantly reassociates and takes up the Giemsa stain, while the G-c rich nucleoprotein is blocked from stain uptake by competitive inhibition with cassium. The absence of specific banding with similar treatments using 0’l-0-2Af KCI, NaCl, MgCl2, HgCI2, GaCI2, and AgN03, and the presence of banding with RbCl, RbI, CsCI, CsF, CsBr, and CS2S04’ suggests that the specificity of the cation in this system resides in the hydrated atomic size (Rb and Cl are both 2-28 A in diameter), while the role of the anion is non-
specific. It is probable
that the dark staining of secondary constrictions of chromosomes 1 and 16 is unrelated to the affinity of csesium to G-c, since similar enhancement of secondary constrictions was seen with CaCl2 and KCI, which did not produce specific banding. If secondary constrictions represent uncoiled D.N.A. regions,3 there must be some protein association which maintains this uncoiled configuration, and perhaps the heat plus anion associated with the CsCI treatment are precipitating these proteins so that prominent staining with Giemsa occurs. This work
was
supported by the Children’s Bureau, H.E.W.
Cytogenetics Unit, State Laboratory of Hygiene, University of Wisconsin, Madison, Wisconsin 53706, U.S.A.
F. MEISNER W. CHUPREVICH B. JOHNSON L. INHORN J. J. CARTER.
L. T. C. S.
NON-EMBOLIC AMPOULES interested by your comments entitled Glass SlR,-—I Embolisms (Dec. 16, p. 1300), particularly the suggestion that " perhaps the day of the glass ampoule is over.... A plastic container whose end could be snipped off might be less risky ". It has come to my notice that such ampoules are available in certain European countries and are marketed (or will shortly be marketed) in the United Kingdom by a company affiliated to Barclay Securities Ltd., 17 Curzon Street, London WI-e.g., water for injection 5 ml. and 10 ml., and normal saline (0-9%) 5 ml. and 10 ml. was
7/52 High Street, Wimbledon, London SW19.
ALAN DAVID.
metoclopromide five minutes the stomach was cleared by one injection of metoclopromide. In only a few instances were further doses (total 30 mg.) necessary. It is a satisfying sight to see the gastric contents funnelling out via the pylorus, leaving the field reasonably clear for examination. to
repeat the intravenous In most
later.
cases
Gastrointestinal Unit, King Edward VIII Hospital, Durban, Natal, South Africa.
ELLIOT BADER.
TRI-IODOTHYRONINE DETERMINATIONS IN URINE
SIR,-We have been working for some time on the detertri-iodothyronine (T3) in human plasma by radioimmunoassay. Specific antibodies against T3 of very mination of
titres have been developed in rabbitsand we have devised a method for measuring T3 in unextracted serum.22 We also investigated T3 excretion in the urine. We therefore wish to comment on the excellent paper by Chan and others.3 In our system 50 1. of native (unextracted) urine is tested directly by radioimmunoassay.2 1-0 ng. of T3 added to 1 ml. of urine was recovered to 102 ±8%. We found a normal excretion-rate in euthyroid patients of 0-4-2-4 g. per 24 hours (n= 40); this range is considerably lower than that mentioned by Chan et al. Whereas the individual excretion-rate seemed to be more or less constant, there is a considerable variation between different individuals (see accompanying figure). This seems to be at least partly due to different body-weight. We could not detect the diurnal rhythm observed with other hormones. Thyrotoxic patients had raised levels of 4-0-14-8 (J.g. per 24 hours. We also observed 9 patients with T3 thyrotoxicosis. Plasma-T3 levels lay in the range 2-1-6-1 ng. per ml. (normal 0-8-1-6), whereas urinary excretion varied from 0-6 to 3-0 (J.g. per 24 hours. Hypothyroid patients had values below 0-3 .g. per 24 hours; and patients with renal insufficiency usually had a T3 excretion in the hypothyroid range. What conclusions can be drawn by comparing the results of the two laboratories ?
high
(1) The normal excretion-rate of T3 in the urine is by no means 1. 2. 3.
Hesch, R. D., Hüfner, M. Acta biol. med. germ. 1972, 28, 861. Hüfner, M., Hesch, R. D. Acta endocr. (in the press). Chan, V., Landon, J., Besser, G. M., Ekins, R. P. Lancet, 1972, ii, 253.
METOCLOPROMIDE AND EMERGENCY ENDOSCOPY FOR UPPER GASTROINTESTINAL BLEEDING
SIR,-The value of emergency endoscopy in the assessand diagnosis of upper gastrointestinal haemorrhage is rapidly becoming established. One of the objections has always been that the view of the stomach may be obscured by fluid and clotted blood and by fluid debris. It is the practice in this unit to attempt endoscopy on all patients with upper gastrointestinal bleeding, and this difficulty has been overcome. Intravenous diazepam is given as premedication. Simultaneously 10 mg. of metoclopromide is given intravenously. If endoscopy shows the stomach still full of blood and debris a further 10 mg. of metoclopromide is given. The patient is then made to lie on his right side for about five minutes before the endoscopy is resumed. The stomach is usually empty at this stage. It may, however, be necessary
ment
2. Fasman, G, D., Adler, A. J. J. 3. Ohnuki, Y. Chromosoma, 1968,
phys. Chem. 1971, 75, 25, 402.
1516.
day
night
day
night
T3 excretion-rate of 2 individuals during five collection periods.
Body-weights 63 kg. (M.H.) and 45 kg. (A.H.). started
at
8 A.M.
day
subsequent 12-hour Urine collection
102 established. Several metabolic products of T3 and T4 in the urine which have not yet been identified might crossreact with the antibody. (2) The increase of apparent T3 in thyrotoxic patients could be due partly to an increase in T4 breakdown products. It is remarkable that the T3 excretion-rate in patients with T3 thyrotoxicosis had a considerable overlap with the normal range, whereas plasma-T3 levels were significantly raised in all cases. (3) T3 excretion is decreased in renal insufficiency, probably because of reduced glomerular filtration, though the contribution of the kidneys itself to T3 excretion is not yet clear. Considering all these points, we do not see any diagnostic advantage in measuring T3 excretion instead of plasma-T3
levels. Rather, there are several additional sources of error and several as yet unclarified factors. We are not convinced that measurement of T3 excretion-rate will be of special benefit in cases of uncertain thyroid hyperfunction. In our opinion plasma-T4, thyroxine-binding index, and T3, the thyrotrophin-releasing-hormone test, and a 99mTcscintigram are sufficient to clarify nearly all thyroid disorders. Medizinische Univ.-poliklinik, 69 Heidelberg, West Germany. Medizinische Klinik, 34 Göttingen, West Germany.
M. HÜFNER.
equivalent of red-cell lysis by IgM antibody for the cells in the presence of complement. Even the release of histamine, &c., from basophils triggered off by the interaction of allergens with IgE antibodies fixed to them turns out to be an active secretory process and not lysis.10,11 If IgE antibodies played any part in tumour rejection it would have to be via an anaphylactic expelling mechanism as contemplated in nematode infestations 1.1-14 and not via tumour-cell lysis. (3) Lastly, the numbers along the ordinate of the figure published by Jacobs et al. should read 1, 2, 3, 4, and 5 in place of 10, 100, and 100,000. ...
The discrepant results given by their two methods in half their cancer patients, and interpreted by them as being due to a tumour-derived factor interfering with IgE/anti-IgE interaction, are highly intriguing; it is, however, difficult to see how an inhibitory factor could have evolved for a completely artificial in-vitro system which has no equivalent in the contemplated in-vivo system; or is it suggested that an inhibitor for IgE/anti-IgE interactions would also inhibit the fundamentally rather different interaction of (hypothetical) IgE antibodies with the corresponding (hypo-
thetical) cancer allergens ? The apparently so high IgE levels have so far been demonstrable only by an inhibition assay-i.e., in what may be called a negative " way. Confirmation in some positive "
R. D. HESCH.
way
is urgently required.
Immunology Cancer Research Unit, Liverpool University, P.O. Box 147, L69 3BX.
Liverpool
CIRCULATING LEVELS OF IgE IN PATIENTS WITH CANCER
SIR,-Jacobs et al. (Nov. 18, p. 1059) claim to be the first to study IgE levels in cancer. May we therefore draw your attention to our own study on precisely this subject, where we investigated in addition to IgE levels also skin reactions to grass-pollen antigens, which are prevalent allergens in this country. We found that 65 cancer patients had rather lower IgE levels and fewer positive skin reactions than 50 unselected normal controlsi.e., our IgE results are similar to those obtained by Jacobs et al. by the same method (radial immunodiffusion 2,3) while our skin-test results appear to be in agreement with the results of Gabriel et al. However, 48 age-matched noncancer surgical patients in the same wards as the cancer patients gave results almost identical to the cancer patients, both in IgE levels and in skin-prick tests. None of our subjects had been treated with cytotoxic drugs. The data given by Jacobs et al. do not include an age-matched control. The paper contains some further superficially plausible but erroneous statements. (1) IgE is certainly not absorbed to " tissue cells sensitised allergen ", but to mast cells and basophils which have special receptors for IgE,5,6 quite unrelated to allergens-a moreover most heterogeneous lot.7 Allergens themselves are in fact most mobile substances spreading rapidly throughout the body, quite in contrast to IgE.B IgE antibodies are of course Dale’s " sessile anaphylactic antibodies.’ (2) There is no shred of evidence that interaction with IgE antibodies ever leads to cell lysis and there is certainly no with
"
1. Augustin, R., Chandradasa, K. D. Int. Archs Allergy, 1971, 41, 141. 2. Rowe, D. S. Bull. Wld Hlth Org. 1969, 40, 613. 3. Augustin, R. in Handbook of Experimental Immunology (edited by D. M. Weir); p. 42·1. Edinburgh (in the press). 4. Gabriel, R., Dudley, B. M., Alexander W. D. Br. J. clin. Pract. 1972, 26, 202 (cited by Jacobs et al.). 5. Ishizaka, T., DeBernardo, R., Tomioka, H., Lichtenstein, L. M., Ishizaka, K. J. Immun. 1972, 108, 1000. 6. Sullivan, A. L., Grimley, P. M., Metzger, H. J. exp. Med. 1971, 134, 1403. 7. Augustin, R. Excerpta med. 1972, International Congress Series 235-II, 9. 8. Spies, J. R., Bernton, H. S., Chambers, D. C. J. Allergy, 1960,
31, 175. 9. Dale, H. H. J. Pharmac. exp. Ther. 1913, 4, 167, 517.
R. AUGUSTIN K. D. CHANDRADASA.
**We showed this letter to Mr Jacobs and his colleagues, and their reply follows.-ED. L. SIR,-We are very grateful to Dr Augustin and Mr Chandradasa for bringing to our attention their excellent communication." We apologise for not having referred to this work, which we missed despite an extensive survey and contact with organisations and specialists in the IgE field. The statement that " the present study is the first, of which we are aware, involving the assay of circulating IgE levels in a large number of patients with cancer " is still true to the extent that we studied a much larger number of subjects using an analytical technique capable of detecting values below the normal range. The failure of Dr Augustin to find significantly low IgE levels in their cancer patients, in contrast to our findings, I may relate to the lack of sensitivity of radial immunodiffusion as compared with radioimmunoassay, or to a difference in the severity of the disease in their subjects. Our paper also remains, as far as we are aware, the first study in which it has been postulated that neoplasms secrete an inhibitory material. However, attention should certainly be drawn to their important preliminary data on lymphocyte transformations and the effect of B. pertussis in inhibiting tumour formation in mice. Certainly IgE is not absorbed to tissue cells sensitised with allergen, an error mistakenly left in the text by one of the authors (J. L.). However, IgE is found free in the circulation and on the surface of basophilic granulocytes,17,18 10. 11. 12. 13. 14. 15. 16. 17. 18.
Lichtenstein, L. M., Osler, A. G. Proc. Soc. exp. Biol. Med. 1966, 121, 808. Lichtenstein, L. M. J. Immun. 1971, 107, 1122. Augustin, R., Ridges, A. P. in Immunity to Protozoa (edited by P. C. C. Garnham, A. E. Pierce, and I. Roitt); p. 296. Oxford, 1963. Ogilvie, B. M. Nature, 1964, 204, 91. Ogilvie, B. M. Immunology, 1967, 12, 113. Augustin, R., Chandradasa, K. D. Int. Archs Allergy, 1971, 41, 141. Jacobs, D., Houri, M., Landon, J., Merrett, T. G. Lancet, 1972, ii, 1059. Tada, T., Ishizaka, K. J. Immun. 1970, 104, 377. Ishizaka, T., Debernardo, R., Tomioka, H., Lichtenstein, L. M., Ishizaka, K. ibid. 1972, 108, 1000.
to
promote conformational
changes.2 It is postulated that under the conditions employed, preferential reversible A-T thermal denaturation occurs at the same time as caesium is complexing with G-c nucleoprotein. In the staining solution, the A-T instantly reassociates and takes up the Giemsa stain, while the G-c rich nucleoprotein is blocked from stain uptake by competitive inhibition with cassium. The absence of specific banding with similar treatments using 0’l-0-2Af KCI, NaCl, MgCl2, HgCI2, GaCI2, and AgN03, and the presence of banding with RbCl, RbI, CsCI, CsF, CsBr, and CS2S04’ suggests that the specificity of the cation in this system resides in the hydrated atomic size (Rb and Cl are both 2-28 A in diameter), while the role of the anion is non-
specific. It is probable
that the dark staining of secondary constrictions of chromosomes 1 and 16 is unrelated to the affinity of csesium to G-c, since similar enhancement of secondary constrictions was seen with CaCl2 and KCI, which did not produce specific banding. If secondary constrictions represent uncoiled D.N.A. regions,3 there must be some protein association which maintains this uncoiled configuration, and perhaps the heat plus anion associated with the CsCI treatment are precipitating these proteins so that prominent staining with Giemsa occurs. This work
was
supported by the Children’s Bureau, H.E.W.
Cytogenetics Unit, State Laboratory of Hygiene, University of Wisconsin, Madison, Wisconsin 53706, U.S.A.
F. MEISNER W. CHUPREVICH B. JOHNSON L. INHORN J. J. CARTER.
L. T. C. S.
NON-EMBOLIC AMPOULES interested by your comments entitled Glass SlR,-—I Embolisms (Dec. 16, p. 1300), particularly the suggestion that " perhaps the day of the glass ampoule is over.... A plastic container whose end could be snipped off might be less risky ". It has come to my notice that such ampoules are available in certain European countries and are marketed (or will shortly be marketed) in the United Kingdom by a company affiliated to Barclay Securities Ltd., 17 Curzon Street, London WI-e.g., water for injection 5 ml. and 10 ml., and normal saline (0-9%) 5 ml. and 10 ml. was
7/52 High Street, Wimbledon, London SW19.
ALAN DAVID.
metoclopromide five minutes the stomach was cleared by one injection of metoclopromide. In only a few instances were further doses (total 30 mg.) necessary. It is a satisfying sight to see the gastric contents funnelling out via the pylorus, leaving the field reasonably clear for examination. to
repeat the intravenous In most
later.
cases
Gastrointestinal Unit, King Edward VIII Hospital, Durban, Natal, South Africa.
ELLIOT BADER.
TRI-IODOTHYRONINE DETERMINATIONS IN URINE
SIR,-We have been working for some time on the detertri-iodothyronine (T3) in human plasma by radioimmunoassay. Specific antibodies against T3 of very mination of
titres have been developed in rabbitsand we have devised a method for measuring T3 in unextracted serum.22 We also investigated T3 excretion in the urine. We therefore wish to comment on the excellent paper by Chan and others.3 In our system 50 1. of native (unextracted) urine is tested directly by radioimmunoassay.2 1-0 ng. of T3 added to 1 ml. of urine was recovered to 102 ±8%. We found a normal excretion-rate in euthyroid patients of 0-4-2-4 g. per 24 hours (n= 40); this range is considerably lower than that mentioned by Chan et al. Whereas the individual excretion-rate seemed to be more or less constant, there is a considerable variation between different individuals (see accompanying figure). This seems to be at least partly due to different body-weight. We could not detect the diurnal rhythm observed with other hormones. Thyrotoxic patients had raised levels of 4-0-14-8 (J.g. per 24 hours. We also observed 9 patients with T3 thyrotoxicosis. Plasma-T3 levels lay in the range 2-1-6-1 ng. per ml. (normal 0-8-1-6), whereas urinary excretion varied from 0-6 to 3-0 (J.g. per 24 hours. Hypothyroid patients had values below 0-3 .g. per 24 hours; and patients with renal insufficiency usually had a T3 excretion in the hypothyroid range. What conclusions can be drawn by comparing the results of the two laboratories ?
high
(1) The normal excretion-rate of T3 in the urine is by no means 1. 2. 3.
Hesch, R. D., Hüfner, M. Acta biol. med. germ. 1972, 28, 861. Hüfner, M., Hesch, R. D. Acta endocr. (in the press). Chan, V., Landon, J., Besser, G. M., Ekins, R. P. Lancet, 1972, ii, 253.
METOCLOPROMIDE AND EMERGENCY ENDOSCOPY FOR UPPER GASTROINTESTINAL BLEEDING
SIR,-The value of emergency endoscopy in the assessand diagnosis of upper gastrointestinal haemorrhage is rapidly becoming established. One of the objections has always been that the view of the stomach may be obscured by fluid and clotted blood and by fluid debris. It is the practice in this unit to attempt endoscopy on all patients with upper gastrointestinal bleeding, and this difficulty has been overcome. Intravenous diazepam is given as premedication. Simultaneously 10 mg. of metoclopromide is given intravenously. If endoscopy shows the stomach still full of blood and debris a further 10 mg. of metoclopromide is given. The patient is then made to lie on his right side for about five minutes before the endoscopy is resumed. The stomach is usually empty at this stage. It may, however, be necessary
ment
2. Fasman, G, D., Adler, A. J. J. 3. Ohnuki, Y. Chromosoma, 1968,
phys. Chem. 1971, 75, 25, 402.
1516.
day
night
day
night
T3 excretion-rate of 2 individuals during five collection periods.
Body-weights 63 kg. (M.H.) and 45 kg. (A.H.). started
at
8 A.M.
day
subsequent 12-hour Urine collection
102 established. Several metabolic products of T3 and T4 in the urine which have not yet been identified might crossreact with the antibody. (2) The increase of apparent T3 in thyrotoxic patients could be due partly to an increase in T4 breakdown products. It is remarkable that the T3 excretion-rate in patients with T3 thyrotoxicosis had a considerable overlap with the normal range, whereas plasma-T3 levels were significantly raised in all cases. (3) T3 excretion is decreased in renal insufficiency, probably because of reduced glomerular filtration, though the contribution of the kidneys itself to T3 excretion is not yet clear. Considering all these points, we do not see any diagnostic advantage in measuring T3 excretion instead of plasma-T3
levels. Rather, there are several additional sources of error and several as yet unclarified factors. We are not convinced that measurement of T3 excretion-rate will be of special benefit in cases of uncertain thyroid hyperfunction. In our opinion plasma-T4, thyroxine-binding index, and T3, the thyrotrophin-releasing-hormone test, and a 99mTcscintigram are sufficient to clarify nearly all thyroid disorders. Medizinische Univ.-poliklinik, 69 Heidelberg, West Germany. Medizinische Klinik, 34 Göttingen, West Germany.
M. HÜFNER.
equivalent of red-cell lysis by IgM antibody for the cells in the presence of complement. Even the release of histamine, &c., from basophils triggered off by the interaction of allergens with IgE antibodies fixed to them turns out to be an active secretory process and not lysis.10,11 If IgE antibodies played any part in tumour rejection it would have to be via an anaphylactic expelling mechanism as contemplated in nematode infestations 1.1-14 and not via tumour-cell lysis. (3) Lastly, the numbers along the ordinate of the figure published by Jacobs et al. should read 1, 2, 3, 4, and 5 in place of 10, 100, and 100,000. ...
The discrepant results given by their two methods in half their cancer patients, and interpreted by them as being due to a tumour-derived factor interfering with IgE/anti-IgE interaction, are highly intriguing; it is, however, difficult to see how an inhibitory factor could have evolved for a completely artificial in-vitro system which has no equivalent in the contemplated in-vivo system; or is it suggested that an inhibitor for IgE/anti-IgE interactions would also inhibit the fundamentally rather different interaction of (hypothetical) IgE antibodies with the corresponding (hypo-
thetical) cancer allergens ? The apparently so high IgE levels have so far been demonstrable only by an inhibition assay-i.e., in what may be called a negative " way. Confirmation in some positive "
R. D. HESCH.
way
is urgently required.
Immunology Cancer Research Unit, Liverpool University, P.O. Box 147, L69 3BX.
Liverpool
CIRCULATING LEVELS OF IgE IN PATIENTS WITH CANCER
SIR,-Jacobs et al. (Nov. 18, p. 1059) claim to be the first to study IgE levels in cancer. May we therefore draw your attention to our own study on precisely this subject, where we investigated in addition to IgE levels also skin reactions to grass-pollen antigens, which are prevalent allergens in this country. We found that 65 cancer patients had rather lower IgE levels and fewer positive skin reactions than 50 unselected normal controlsi.e., our IgE results are similar to those obtained by Jacobs et al. by the same method (radial immunodiffusion 2,3) while our skin-test results appear to be in agreement with the results of Gabriel et al. However, 48 age-matched noncancer surgical patients in the same wards as the cancer patients gave results almost identical to the cancer patients, both in IgE levels and in skin-prick tests. None of our subjects had been treated with cytotoxic drugs. The data given by Jacobs et al. do not include an age-matched control. The paper contains some further superficially plausible but erroneous statements. (1) IgE is certainly not absorbed to " tissue cells sensitised allergen ", but to mast cells and basophils which have special receptors for IgE,5,6 quite unrelated to allergens-a moreover most heterogeneous lot.7 Allergens themselves are in fact most mobile substances spreading rapidly throughout the body, quite in contrast to IgE.B IgE antibodies are of course Dale’s " sessile anaphylactic antibodies.’ (2) There is no shred of evidence that interaction with IgE antibodies ever leads to cell lysis and there is certainly no with
"
1. Augustin, R., Chandradasa, K. D. Int. Archs Allergy, 1971, 41, 141. 2. Rowe, D. S. Bull. Wld Hlth Org. 1969, 40, 613. 3. Augustin, R. in Handbook of Experimental Immunology (edited by D. M. Weir); p. 42·1. Edinburgh (in the press). 4. Gabriel, R., Dudley, B. M., Alexander W. D. Br. J. clin. Pract. 1972, 26, 202 (cited by Jacobs et al.). 5. Ishizaka, T., DeBernardo, R., Tomioka, H., Lichtenstein, L. M., Ishizaka, K. J. Immun. 1972, 108, 1000. 6. Sullivan, A. L., Grimley, P. M., Metzger, H. J. exp. Med. 1971, 134, 1403. 7. Augustin, R. Excerpta med. 1972, International Congress Series 235-II, 9. 8. Spies, J. R., Bernton, H. S., Chambers, D. C. J. Allergy, 1960,
31, 175. 9. Dale, H. H. J. Pharmac. exp. Ther. 1913, 4, 167, 517.
R. AUGUSTIN K. D. CHANDRADASA.
**We showed this letter to Mr Jacobs and his colleagues, and their reply follows.-ED. L. SIR,-We are very grateful to Dr Augustin and Mr Chandradasa for bringing to our attention their excellent communication." We apologise for not having referred to this work, which we missed despite an extensive survey and contact with organisations and specialists in the IgE field. The statement that " the present study is the first, of which we are aware, involving the assay of circulating IgE levels in a large number of patients with cancer " is still true to the extent that we studied a much larger number of subjects using an analytical technique capable of detecting values below the normal range. The failure of Dr Augustin to find significantly low IgE levels in their cancer patients, in contrast to our findings, I may relate to the lack of sensitivity of radial immunodiffusion as compared with radioimmunoassay, or to a difference in the severity of the disease in their subjects. Our paper also remains, as far as we are aware, the first study in which it has been postulated that neoplasms secrete an inhibitory material. However, attention should certainly be drawn to their important preliminary data on lymphocyte transformations and the effect of B. pertussis in inhibiting tumour formation in mice. Certainly IgE is not absorbed to tissue cells sensitised with allergen, an error mistakenly left in the text by one of the authors (J. L.). However, IgE is found free in the circulation and on the surface of basophilic granulocytes,17,18 10. 11. 12. 13. 14. 15. 16. 17. 18.
Lichtenstein, L. M., Osler, A. G. Proc. Soc. exp. Biol. Med. 1966, 121, 808. Lichtenstein, L. M. J. Immun. 1971, 107, 1122. Augustin, R., Ridges, A. P. in Immunity to Protozoa (edited by P. C. C. Garnham, A. E. Pierce, and I. Roitt); p. 296. Oxford, 1963. Ogilvie, B. M. Nature, 1964, 204, 91. Ogilvie, B. M. Immunology, 1967, 12, 113. Augustin, R., Chandradasa, K. D. Int. Archs Allergy, 1971, 41, 141. Jacobs, D., Houri, M., Landon, J., Merrett, T. G. Lancet, 1972, ii, 1059. Tada, T., Ishizaka, K. J. Immun. 1970, 104, 377. Ishizaka, T., Debernardo, R., Tomioka, H., Lichtenstein, L. M., Ishizaka, K. ibid. 1972, 108, 1000.