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DANGERS OF NATURAL FOODSTUFFS
601 in the United States to which his staff member plans to come had not told him until relatively late in the negotiations that E.C.F.M.G. certification would be required. We are trying to keep all of our colleagues informed, but I am sure that physicians in the United States who do not have frequent dealings with foreign medical graduates occasionally forget to mention the requirement. We hope the situation will improve as time
obtain a positive cutaneous reaction, which was not shown by control children. Adolfo Lutz Institute, Y. LEVANON State Public Health Laboratory, S. M. O. ROSSETINI. São Paulo, Brazil.
soes on.
PANCREATIC DIABETES SIR,-In reply to the letter by Dr. Peters and his colleagues (Jan. 8) about my joint article on plasma-insulin levels in pancreatic diabetes,! I should like to make the following points. My colleagues and I actually submitted our paper as a preliminary communication, being fully aware of the fact that our studies were incomplete. We also intended to publish fuller details of methods in a later paper, together with the insulin response to a glucose load and other data. We are not quite in agreement with the hypothesis that the " fasting insulin level in pancreatic diabetes is the maximum in Our results indicate that at least these response " patients. some of our patients are capable of an increased insulin response to glucose loading. The question is under further investigation. The standards used by my colleagues and I were those of bovine insulin (Boots Pure Drugs Co. Ltd., Nottingham). The " antiserum " used was the " binding reagent " made by the Wellcome Research Foundation, and supplied by the Radiochemical Centre, Amersham. No special precautions were taken to separate serum-insulin from insulin antibodies. Only three of the patients of my colleagues and I were having insulin. We agree that the results on these may be invalid. We are also aware of the statements that in pancreatectomised dogs there is a persistence of insulin-like activity (I.L.A.). On the other hand in pancreatitis we certainly expected to find a mean fall rather than a mean rise. We are unclear on what grounds Dr. Peters and his colleagues consider that patients with chronic pancreatitis are " abnormally sensitive to insulin ". We certainly disagree with this
G. HALSEY HUNT Executive Director, Evanston,
Educational Council for
Illinois 60201, U.S.A.
Foreign Medical Graduates.
HYDROFLUORIC ACID IN WINDOW-CLEANING SIR,-The use of hydrofluoric acid for cleaning the exterior surface of roof-lights should be stopped, not only for the medical reasons so succinctly stated by Dr. MacBain and Dr. White (Feb. 5), but also for scientific and economic reasons. Most glass used in roof-lights is of the ordinary soda-lime variety. Application of only a 1 % hydrofluoric-acid solution removes a layer, 10-15 [t in depth, from the surface of the glass within three minutes. This is well within the time-interval between the application of the acid solution and its hosing off. That the removal of this layer of glass actually occurs has been shown in the following manner. Certain molten, high-temperature, salt baths effect the inward diffusion of potassium ions and the outward flow of sodium ions in soda-lime glass, with resultant exchange of potassium for sodium. The depth of potassium penetration can be measured by X-ray diffraction. Thus the effective depth of hydrofluoric acid etching upon glass can be determined from the decrease in potassium X-ray diffraction-counts and in the weight of the sample as one increases either the length of time of hydrofluoric-acid etching or the concentration of the acid. The strength of soda-lime-glass rods etched in hydrofluoric acid is considerably less than that of unetched glass when tested on a Tinius-Olsen glass-breakage apparatus. Further, the etched material shows a more random, and hence
dangerous, break-pattern. Consequently, there is not only an immediate health hazard to the workers who use hydrofluoric acid as a cleaning agent, but also a danger to others because of the weakened structure of the glass itself. more
ARNOLD G. PHILLIPS.
DANGERS OF NATURAL FOODSTUFFS SIR,-Dr. Krikler and Dr. Lewis1 have commented on sensitivity to cacao products. Work in this laboratory 2-5 has shown that unprocessed cacao beans contain at least two immunogenic factors,2which have been isolated and purified.5 Chocolate flavour results from deliberate farm-fermentation of cacao beans. If this fermentation is not complete antigens remain, and are contained in the resulting industrial product. These antigens are split during a full fermentation process.4 Drying of insufficiently fermented cacao beans does not denature the antigens because these are polysaccharides. The nature of sensitisation is unknown, and one might speculate whether consumers of insufficiently fermented cacao can become sensitised. It is important to remember that in the fermentation process of cacao, flies and microorganisms such as saccharomyces and acetobacteria are present. These microorganisms probably contain antigens that might stimulate production of cross-reacting antibodies against antigens from other microorganisms present normally in foods. Antigens from such sources might provoke allergic reactions. We therefore tested children sensitive to chocolate by using the antigens isolated from unfermented cacao. It was possible to 1. 2. 3. 4. 5.
Krikler, D. M., Lewis, B. Lancet, 1965, i, 1166. Levanon, Y., Martelli, H. L. Biochem. Biol. Sper. 1964, 3, 3. Levanon, Y., Rossetini, S. M. O. J. Food Sci. 1965, 30, 719. Levanon, Y. Biochem. Biol. Sper. 1965, 4, 131. Levanon, Y., Rossetini, S. M. O. J. Food Sci. (in the press).
assumption. In answer to Dr. Ravina’s letter (Feb. 19), we do hope and intend to consider patients more individually in a later, more definitive publication. Briefly, the majority of our patients were men under 45 years, usually without a family history of diabetes, in whom we hope to study synalbumin antagonists. Liver cirrhosis is remarkably uncommon in our patients with alcoholic pancreatitis. So far we have not studied the immunologically detectable insulin (I.D.I.) and serum-l.L.A. in a sufficient number of individuals to say whether patients with high I.D.I. values also have high serum-l.L.A. values. Endocrine Research Group, Department of Medicine, Medical School,
Observatory, Cape Town, South Africa.
P. KELLER.
ANTI-MONGOLISM the comments by Dr. Court Brown and his SIR,-Following on the article by Dr. Reisman and his colleagues (Feb. 26) colleagues on an infant with a partial monosomy of the 21 chromosome, I would agree that studies should be carried out on the parents to investigate the possibility of structural heterozygosity. The criticism of Dr. Court Brown and his colleagues is not justified, however, in view of the obvious similarity between their case and the one described by Lejeune et al. in which the parents were normal. What seems to be more important is the choice of the term to describe such infants. Clinically there is little justification in calling them " anti-mongols ", and presumably this name must therefore depend on the apparent partial monosomy for chromosome 21. 1. 2.
Keller, P., Bark, S., Jackson, W. P. U., Marks, I. N., O’Reilly, I. G. Lancet, 1965, ii, 1211. Lejeune, J., Berger, R., Rethore, M., Archambault, L., Jerome, H., Thieffry, S., Aicardi, J., Broyer, H., Lafourcade, J., Cruveiller, J., Turpin, R. C.r. hebd. Séanc. Acad. Sci., Paris, 1964, 259, 4187.
obtain a positive cutaneous reaction, which was not shown by control children. Adolfo Lutz Institute, Y. LEVANON State Public Health Laboratory, S. M. O. ROSSETINI. São Paulo, Brazil.
soes on.
PANCREATIC DIABETES SIR,-In reply to the letter by Dr. Peters and his colleagues (Jan. 8) about my joint article on plasma-insulin levels in pancreatic diabetes,! I should like to make the following points. My colleagues and I actually submitted our paper as a preliminary communication, being fully aware of the fact that our studies were incomplete. We also intended to publish fuller details of methods in a later paper, together with the insulin response to a glucose load and other data. We are not quite in agreement with the hypothesis that the " fasting insulin level in pancreatic diabetes is the maximum in Our results indicate that at least these response " patients. some of our patients are capable of an increased insulin response to glucose loading. The question is under further investigation. The standards used by my colleagues and I were those of bovine insulin (Boots Pure Drugs Co. Ltd., Nottingham). The " antiserum " used was the " binding reagent " made by the Wellcome Research Foundation, and supplied by the Radiochemical Centre, Amersham. No special precautions were taken to separate serum-insulin from insulin antibodies. Only three of the patients of my colleagues and I were having insulin. We agree that the results on these may be invalid. We are also aware of the statements that in pancreatectomised dogs there is a persistence of insulin-like activity (I.L.A.). On the other hand in pancreatitis we certainly expected to find a mean fall rather than a mean rise. We are unclear on what grounds Dr. Peters and his colleagues consider that patients with chronic pancreatitis are " abnormally sensitive to insulin ". We certainly disagree with this
G. HALSEY HUNT Executive Director, Evanston,
Educational Council for
Illinois 60201, U.S.A.
Foreign Medical Graduates.
HYDROFLUORIC ACID IN WINDOW-CLEANING SIR,-The use of hydrofluoric acid for cleaning the exterior surface of roof-lights should be stopped, not only for the medical reasons so succinctly stated by Dr. MacBain and Dr. White (Feb. 5), but also for scientific and economic reasons. Most glass used in roof-lights is of the ordinary soda-lime variety. Application of only a 1 % hydrofluoric-acid solution removes a layer, 10-15 [t in depth, from the surface of the glass within three minutes. This is well within the time-interval between the application of the acid solution and its hosing off. That the removal of this layer of glass actually occurs has been shown in the following manner. Certain molten, high-temperature, salt baths effect the inward diffusion of potassium ions and the outward flow of sodium ions in soda-lime glass, with resultant exchange of potassium for sodium. The depth of potassium penetration can be measured by X-ray diffraction. Thus the effective depth of hydrofluoric acid etching upon glass can be determined from the decrease in potassium X-ray diffraction-counts and in the weight of the sample as one increases either the length of time of hydrofluoric-acid etching or the concentration of the acid. The strength of soda-lime-glass rods etched in hydrofluoric acid is considerably less than that of unetched glass when tested on a Tinius-Olsen glass-breakage apparatus. Further, the etched material shows a more random, and hence
dangerous, break-pattern. Consequently, there is not only an immediate health hazard to the workers who use hydrofluoric acid as a cleaning agent, but also a danger to others because of the weakened structure of the glass itself. more
ARNOLD G. PHILLIPS.
DANGERS OF NATURAL FOODSTUFFS SIR,-Dr. Krikler and Dr. Lewis1 have commented on sensitivity to cacao products. Work in this laboratory 2-5 has shown that unprocessed cacao beans contain at least two immunogenic factors,2which have been isolated and purified.5 Chocolate flavour results from deliberate farm-fermentation of cacao beans. If this fermentation is not complete antigens remain, and are contained in the resulting industrial product. These antigens are split during a full fermentation process.4 Drying of insufficiently fermented cacao beans does not denature the antigens because these are polysaccharides. The nature of sensitisation is unknown, and one might speculate whether consumers of insufficiently fermented cacao can become sensitised. It is important to remember that in the fermentation process of cacao, flies and microorganisms such as saccharomyces and acetobacteria are present. These microorganisms probably contain antigens that might stimulate production of cross-reacting antibodies against antigens from other microorganisms present normally in foods. Antigens from such sources might provoke allergic reactions. We therefore tested children sensitive to chocolate by using the antigens isolated from unfermented cacao. It was possible to 1. 2. 3. 4. 5.
Krikler, D. M., Lewis, B. Lancet, 1965, i, 1166. Levanon, Y., Martelli, H. L. Biochem. Biol. Sper. 1964, 3, 3. Levanon, Y., Rossetini, S. M. O. J. Food Sci. 1965, 30, 719. Levanon, Y. Biochem. Biol. Sper. 1965, 4, 131. Levanon, Y., Rossetini, S. M. O. J. Food Sci. (in the press).
assumption. In answer to Dr. Ravina’s letter (Feb. 19), we do hope and intend to consider patients more individually in a later, more definitive publication. Briefly, the majority of our patients were men under 45 years, usually without a family history of diabetes, in whom we hope to study synalbumin antagonists. Liver cirrhosis is remarkably uncommon in our patients with alcoholic pancreatitis. So far we have not studied the immunologically detectable insulin (I.D.I.) and serum-l.L.A. in a sufficient number of individuals to say whether patients with high I.D.I. values also have high serum-l.L.A. values. Endocrine Research Group, Department of Medicine, Medical School,
Observatory, Cape Town, South Africa.
P. KELLER.
ANTI-MONGOLISM the comments by Dr. Court Brown and his SIR,-Following on the article by Dr. Reisman and his colleagues (Feb. 26) colleagues on an infant with a partial monosomy of the 21 chromosome, I would agree that studies should be carried out on the parents to investigate the possibility of structural heterozygosity. The criticism of Dr. Court Brown and his colleagues is not justified, however, in view of the obvious similarity between their case and the one described by Lejeune et al. in which the parents were normal. What seems to be more important is the choice of the term to describe such infants. Clinically there is little justification in calling them " anti-mongols ", and presumably this name must therefore depend on the apparent partial monosomy for chromosome 21. 1. 2.
Keller, P., Bark, S., Jackson, W. P. U., Marks, I. N., O’Reilly, I. G. Lancet, 1965, ii, 1211. Lejeune, J., Berger, R., Rethore, M., Archambault, L., Jerome, H., Thieffry, S., Aicardi, J., Broyer, H., Lafourcade, J., Cruveiller, J., Turpin, R. C.r. hebd. Séanc. Acad. Sci., Paris, 1964, 259, 4187.