- Email: [email protected]
EFFECT OF ALCOHOL ON GLUCOSE TOLERANCE
47 little below 1000 W.L.M., although the few cases make this conclusion very uncertain. Finally, we think Dr. Archer is quite right in pointing out radiation as the most essential w-tiological factor causing lung cancer in different groups of miners, and his dose/ response relationship will probably be valuable for the recognition of other possible additional carcinogenic factors in mines. a
Department of Occupational Medicine, Regional Hospital, 701 85
Örebro,
OLAV AXELSON MAGNUS REHN.
Sweden.
N.B.T. TESTS IN DOG NEUTROPHILS reports of raised nitroblue-tetrazolium in the neutrophils of human beings with (N.B.T.) parasitic diseases prompt us to communicate our preliminary observations on N.B.T. reactions in canine neutrophils and the effects of Dirofilaria immitis (dog heartworm) on that reaction. A standardised N.B.T. method was developed for testing of dog neutrophils. The concentration of heparin was a critical factor determining the ranges of " normal " scores obtained, and will be the subject of a detailed report. In a series of experiments using 10 units heparin per ml., fourteen normal dogs showed neutrophil scores of 6-24%. Cells from three dogs infested with D. immitis (chronic infections of unknown duration) showed a significant rise in neutrophil N.B.T. scores (33%, 54%, and 63%). Plasma from the high-scoring dog-in which comprehensive investigations for bacterial infection were negative-was capable of invoking a raised N.B.T. response when incubated with normal-dog neutrophils (control with normal plasma 18%, D. immitis plasma 68%). Dog heartworm was obtained from another dog at necropsy, and frozen. Pieces of the thawed worm, incubated with normal canine neutrophils, resulted in a significant rise in N.B.T. scores (control 5%, frozen heartworm 61%). These observations suggest that some component of D. immitis present in the plasma of infested dogs (and in the parasite) can act directly on neutrophils to alter N.B.T. response, probably through effects on membrane properties of the leucocytes.
SIR,-The
test scores
Department of Pathology, Rhode Island Hospital, and Brown University, Providence, Rhode Island, U.S.A.
of metabolism virtually unaffected by other compounds), and a disposition to diabetes would understandably prolong the intolerance as found in some of the cases quoted by Dr. Phillips. JOHN G. BENJAFIELD Harley Street Laboratories, L. F. RUTTER. 6 Harley Street, London W1N 1AA. rate
PATRICIA FARNES MORRIS L. POVAR
JULIE FIESCHKO BARBARA E. BARKER.
EFFECT OF ALCOHOL ON GLUCOSE
TOLERANCE
SIR,-Reconciliation of some of Dr. Phillips’ findings (Dec. 11, p. 1317) and those of Miss Dornhorst and Miss Ouyang (Oct. 30, p. 957) on effects of alcohol on glucose tolerance is possible if it is accepted that preferential utilisation of alcohol by the tissues occurs as suggested in our letter (Nov. 20, p. 1145). For example, such a mechanism could account for the more pronounced glucose intolerance and augmented insulin response found by Dr. Phillips after administration of larger amounts of alcohol than those given by Miss Dornhorst and Miss Ouyang. This would also account for the persistence of these effects " when alcohol should no longer have been present in the blood ", as conversion of the alcohol to compounds capable of being utilised by the Krebs cycle would have occurred, and these would be expected to have a temporary suppressive effect on further glucose metabolism by the " feed-back " principle. On this basis, duration of effects observed may be proportional to total calories available from the test doses of glucose and alcohol (particularly as alcohol shows a steady
A MORE SENSITIVE TEST FOR ALPHA-FETOPROTEIN
SiR,—Your correspondence columns have been a valuable forum for information concerning alpha-fetoprotein (A.F.P.) in primary liver cancer-a disease important in many developing countries. We are currently using a radioimmunoassay (R.I.A.) to detect low concentrations of A.F.P. The procedure is based on the method of Hunter, using purified A.F.P.2 The accompanying figure demonstrates a current batch of our results and highlights many of the problems in
Serum-A.F.P. levels in four
categories of Bantu miners. Median results are given in the upper two categories. The X-axis had two scales; the A.F.P. level in ng./ml. and the percentage of the total radioactivity precipitated in the R.I.A. The broken X-axes in the lower two categories indicate results beyond the range of the graph. cancer (P.L.c.) in susceptible These results have now been repeatedly confirmed over two years. With regard to the R.I.A. technique, no claims are made for the accuracy below 10 ng. per ml. Bantu miners were bled at the beginning of their contracts and again after a year on the mines. The median results are very close (11and 13 ng. per ml.), but more cases with considerably higher results (e.g., 60 ng. per ml.) were consistently found on arrival at the mines. These men were all clinically well and remained so. The men with higher A.F.P. results most often came from high-risk P.L.c. areas of southern Africa. In fact, Bantu from highrisk areas showed a bimodal distribution of A.F.P. levels with the one mode 3-4 times higher than the normal.3 We would like to be able to conclude that the change from a diet possibly containing a hepatotoxin with carcinogenic potential to the balanced diet on the mines reversed the A.F.P.-producing process, but this must at present remain
dealing with primary liver
populations.
speculation. Immunodiffusional A.F.P. assay without autoradiography4 has a limit of sensitivity in routine estimations of about Hunter, W. M. in Handbook of Experimental Immunology; p. 608. Oxford, 1967. 2. Purves, L. R., van der Merwe, E., Bersohn, I. S. Afr. med. J. 1970, 44, 1264. 3. Purves, L. R. in Proceedings of Symposium on Mycotoxins in Human Health. London, 1971. 4. Rowe, D. S. Bull. Wld Hlth Org. 1969, 40, 613. 1.
Department of Occupational Medicine, Regional Hospital, 701 85
Örebro,
OLAV AXELSON MAGNUS REHN.
Sweden.
N.B.T. TESTS IN DOG NEUTROPHILS reports of raised nitroblue-tetrazolium in the neutrophils of human beings with (N.B.T.) parasitic diseases prompt us to communicate our preliminary observations on N.B.T. reactions in canine neutrophils and the effects of Dirofilaria immitis (dog heartworm) on that reaction. A standardised N.B.T. method was developed for testing of dog neutrophils. The concentration of heparin was a critical factor determining the ranges of " normal " scores obtained, and will be the subject of a detailed report. In a series of experiments using 10 units heparin per ml., fourteen normal dogs showed neutrophil scores of 6-24%. Cells from three dogs infested with D. immitis (chronic infections of unknown duration) showed a significant rise in neutrophil N.B.T. scores (33%, 54%, and 63%). Plasma from the high-scoring dog-in which comprehensive investigations for bacterial infection were negative-was capable of invoking a raised N.B.T. response when incubated with normal-dog neutrophils (control with normal plasma 18%, D. immitis plasma 68%). Dog heartworm was obtained from another dog at necropsy, and frozen. Pieces of the thawed worm, incubated with normal canine neutrophils, resulted in a significant rise in N.B.T. scores (control 5%, frozen heartworm 61%). These observations suggest that some component of D. immitis present in the plasma of infested dogs (and in the parasite) can act directly on neutrophils to alter N.B.T. response, probably through effects on membrane properties of the leucocytes.
SIR,-The
test scores
Department of Pathology, Rhode Island Hospital, and Brown University, Providence, Rhode Island, U.S.A.
of metabolism virtually unaffected by other compounds), and a disposition to diabetes would understandably prolong the intolerance as found in some of the cases quoted by Dr. Phillips. JOHN G. BENJAFIELD Harley Street Laboratories, L. F. RUTTER. 6 Harley Street, London W1N 1AA. rate
PATRICIA FARNES MORRIS L. POVAR
JULIE FIESCHKO BARBARA E. BARKER.
EFFECT OF ALCOHOL ON GLUCOSE
TOLERANCE
SIR,-Reconciliation of some of Dr. Phillips’ findings (Dec. 11, p. 1317) and those of Miss Dornhorst and Miss Ouyang (Oct. 30, p. 957) on effects of alcohol on glucose tolerance is possible if it is accepted that preferential utilisation of alcohol by the tissues occurs as suggested in our letter (Nov. 20, p. 1145). For example, such a mechanism could account for the more pronounced glucose intolerance and augmented insulin response found by Dr. Phillips after administration of larger amounts of alcohol than those given by Miss Dornhorst and Miss Ouyang. This would also account for the persistence of these effects " when alcohol should no longer have been present in the blood ", as conversion of the alcohol to compounds capable of being utilised by the Krebs cycle would have occurred, and these would be expected to have a temporary suppressive effect on further glucose metabolism by the " feed-back " principle. On this basis, duration of effects observed may be proportional to total calories available from the test doses of glucose and alcohol (particularly as alcohol shows a steady
A MORE SENSITIVE TEST FOR ALPHA-FETOPROTEIN
SiR,—Your correspondence columns have been a valuable forum for information concerning alpha-fetoprotein (A.F.P.) in primary liver cancer-a disease important in many developing countries. We are currently using a radioimmunoassay (R.I.A.) to detect low concentrations of A.F.P. The procedure is based on the method of Hunter, using purified A.F.P.2 The accompanying figure demonstrates a current batch of our results and highlights many of the problems in
Serum-A.F.P. levels in four
categories of Bantu miners. Median results are given in the upper two categories. The X-axis had two scales; the A.F.P. level in ng./ml. and the percentage of the total radioactivity precipitated in the R.I.A. The broken X-axes in the lower two categories indicate results beyond the range of the graph. cancer (P.L.c.) in susceptible These results have now been repeatedly confirmed over two years. With regard to the R.I.A. technique, no claims are made for the accuracy below 10 ng. per ml. Bantu miners were bled at the beginning of their contracts and again after a year on the mines. The median results are very close (11and 13 ng. per ml.), but more cases with considerably higher results (e.g., 60 ng. per ml.) were consistently found on arrival at the mines. These men were all clinically well and remained so. The men with higher A.F.P. results most often came from high-risk P.L.c. areas of southern Africa. In fact, Bantu from highrisk areas showed a bimodal distribution of A.F.P. levels with the one mode 3-4 times higher than the normal.3 We would like to be able to conclude that the change from a diet possibly containing a hepatotoxin with carcinogenic potential to the balanced diet on the mines reversed the A.F.P.-producing process, but this must at present remain
dealing with primary liver
populations.
speculation. Immunodiffusional A.F.P. assay without autoradiography4 has a limit of sensitivity in routine estimations of about Hunter, W. M. in Handbook of Experimental Immunology; p. 608. Oxford, 1967. 2. Purves, L. R., van der Merwe, E., Bersohn, I. S. Afr. med. J. 1970, 44, 1264. 3. Purves, L. R. in Proceedings of Symposium on Mycotoxins in Human Health. London, 1971. 4. Rowe, D. S. Bull. Wld Hlth Org. 1969, 40, 613. 1.