Acta Pzdiutr Scund 65: 145-149, 1976
SERUM ISOAMYLASES I N CYSTIC FIBROSIS G . SKUDE and H . KOLLBERG From the Department of Clinical Chemistry, Unirzersiry of Lund, Malmo General Hospital, S-21401 Malmo and the Department of Pediatrics, University of Uppsala, Uppsala, Su'eden
ABSTRACT. Skude, G. and Kollberg, H. (Department of Clinical Chemistry, University of Lund, Malmo General Hospital, Malmo and Department of Pediatrics, University of Uppsala, Uppsala, Sweden). Serum isoamylases in cystic flbrosis. Acta Paediatr Scand, 65: 145, 1976.Salivary and pancreatic isoamylases were determined in the sera of 33 patients with cystic fibrosis (CF) and in 34 CF-parents. Pancreatic serum isoamylase activities were greatly decreased in patients with CF, and only two values from this group fell within the normal range. Salivary isoamylases, however, were markedly increased so that the total serum amylase activities were normal. We interpret the low pancreatic isoamylase levels in serum to reflect reduced exocrine masses in the pancreas of CF-children. In heterozygotes, the mean activity of the pancreatic isoamylase was significantly higher than in the reference group, while salivary isoamylases were within the normal range. Due to a genetic polymorphism pancreatic isoamylase may occur in two main fractions. This variant type of pancreatic isoamylase appeared more frequently in CF-heterozygotes than was expected from a reference group of blood donors. KEY WORDS: Amylase, cystic fibrosis, genetic polymorphism, pancreatic isoamylase, salivary isoamylase
Exocrine secretions from the pancreas are markedly reduced in patients with cystic fibrosis (CF) (10, 21, 22), while the amylase contents of the saliva are reported variously as low, normal, or even increased (3, 15, 18, 20). Newly developed techniques have made possible the separation of the pancreatic and salivary isoamylases of serum ( 5 , 17, 23, 26). Decreased exocrine function of the pancreas may result in reduced pancreatic isoamylases in serum (23, 27). Recently pancreatic isoamylases have been reported low in a few patients with C F ( 1 1 , 23, 24, 27) while salivary isoamylases have been reported high (24). The exocrine functions of the pancreas and the salivary glands develop successively during infancy and early childhood (7, 18, 24). Thus children with cystic fibrosis n u s t be compared for isoamylases to normal children of corre-
sponding age. This paper reports the activities and patterns of pancreatic and salivary isoamylases in the sera of patients with C F and of CF-parents, who are obliged to be heterozygous for the CF-gene, as compared to agematched controls who were healthy. MATERIAL AND METHODS The material comprised, 33 patients with C F ( 1 5 males and 18 females including 3 sib pairs) whose ages ranged from 3 months to 28 years, and averaged 10.5 years (for details according to age see Fig. 1). All CF-patients had one or more typical clinical symptoms (30 had chronic pulmonary disease, 32 had nutritional problems and several had nasal polyposis, chronic sinusitis, cirrhosis of the liver, etc.). All patients had abnormally high sweat electrolytes as studied by the pilocarpine-iontophoresis method (8). Only one of the CF-patients did not require supplemental pancreatic enzyme therapy. The 34 CF-heterozygote subjects studied were parents (10 fathers and 24 mothers) of CF-patients. Their ages vaned from 24 to 55 years and averaged 37 ycars. Acla PrPdiatr Scand 6S
146
u/ 1 2 50
G . Skude and H . Kollberg S A L I V A RY AMYLASE
.
250
-
P A N C R EA T l C AMVLASE
150 -
2 00
200
... .. 1 so
100
100
50
50
0
0 CYSTIC F I B R O S I S
PARENTS
Fig. I . Activities of salivary isoamylase and of pancreatic
isoamylase in the sera of CF-patients and CF-parents. The solid line indicates the mean values for age-matched
AGE YEARS CYSTIC FIBROSIS
PARENTS
reference individuals while the hatched area indicates the range of normal values (mean plus and minus two standard deviations).
d.f.=91, pp>O.OOl]) (Fig. 1). The salivary isoamylase patterns in serum were entirely similar in all groups of patients studied. The pancreatic isoamylase patterns were not evident in most of the CF-patients because of low activities. Two children with C F exhibited clear patterns. One was homozygote for the most frequent genetic type of pancreatic isoamylase consisting of one main pancreatic fraction (23). The other was heterozygote at this locus and had two main pancreatic fractions (Fig. 2, sample c ) . Among the parents, 26 were homozygotes for the most frequent gene (Fig. 2. sampled), 7 were heterozygotes and one was homozygote for the variant gene (Fig. 2, sample e ) . In a series of 383 blood donors, the corresponding phenotype frequencies were 86.4, 12.3 and 1.3 %, respectively (25). Thus, the polymorphic variant gene appeared more frequently than expected in this small group of CF-parents (x2=3.16, d.f.= 1 ,p?O.O5).
DISCUSSION Finding total serum amylase activities normal in CF-patients accords with earlier reports ( 1 , 27). The distribution of isoamylases is markedly abnormal, however, because the pancreatic isoamylase is greatly reduced and the salivary isoamylase is markedly increased. These results agree with the results of Taussig and associates (27), who reported complete
a
b
C
d
e
Fig. 2. Serum isoamylase patterns (salivary, S , and pancreatic, P).Sample a: normal isoamylase pattern, activity 80+80 U/l. Sample b: typical pattern of C F activity 180+0 U/1. Sample c: CF, combined with heterozygosity for polymorphic pancreatic isoamylase gene, activity 150+50 U/I. Sampled: typical CF-heterozygosity, activity 7 0 f 140 U/1. Sample e: CF-heterozygosity and homozygosity for polymorphic pancreatic isoamylase gene, activity 85+50 U/I.
absence of the pancreatic isoamylases in 13 of 19 CF-patients studied, and found low activities in 4, and normal activities in 2. Our results conflict sharply with the report by v. Husen and associates ( 1 l ) , who found no salivary isoamylase in the sera of 13 CF-patients on study of 34 patients. This discrepancy might be explained by inadequate technique (starch-iodine staining). The marked decrease in pancreatic isoamylase activity in C F reflects the reduced mass of exocrine cells (6, 22, 23) in the pancreas. Supplemental pancreatic enzyme therapy does not affect serum amylase activity (25, 27). Abnormally high activities of pancreatic isoamylase in the sera of CF-heterozygotes have not been reported by others. The reason for this finding is unknown but it may reflect a disturbed exocrine function of the pancreas. An increased salivary isoamylase in the serum of CF-patients is confirmed in this study. We also report quantitative determinations of this isoamylase which have not previously been reported in these patients. The possibility, that this increase could be compensatory to the decreased pancreatic isoamylase seems unlikely. It may be that the Acta Pzdiatr Scand 65
148
G . Skude and H . Kollberg
salivary glands are also affected in CF, which would be in accordance with earlier observations (2, 14, 15) and in concert with the idea that CF is a generalized disease (4, 12, 19, 21 ). Observations that salivary isoamylases have ciliostatic properties (9, 16) could even suggest a central role for these enzymes in the pathogenesis of CF. The pancreatic isoamylase patterns in the CF-heterozygotes revealed an unusually high frequency of the gene associated with an additional slow migrating fraction. This gene was also present in one CF-patient, although pancreatic isoamylases were clearly visualized in only two. It is apparent that a larger number of CF-parents need to be studied. The present findings must be interpreted cautiously because of the small size of our group. The diagnosis of CF depends on the evaluation of clinical symptoms and of the interpretation of results from sweat electrolyte measurements by the pilocarpine iontophoresis method. There are, however, difficulties with the diagnosis in about one or two per cent of CF-children, who have sweat electrolytes within the normal limits. We propose the specific determination of serum isoamylases as a valuable diagnostic tool in CF. The characteristic pattern includes total serum amylase activities, which are normal or slightly increased, and pancreatic isoamylase activities which are markedly decreased. The activities of pancreatic isoarnylases do not develop normally during early childhood (24) so that decreased pancreatic isoamylase activities cannot be helpful diagnostically until after the age of three years. Even so, many children with CF remain undiagnosed beyond that age (13). The finding of high salivary isoamylase activity is suggestive of CF, but can never be considered diagnostic. ACKNOWLEDGEMENTS This investigation was supported by grants from the Medical Faculty, University of Lund, the Hierta-Retzius Foundation, the Swedish Society for Medical Research, Marcus Borgstroms Foundation, Sunnedahls Foundation, Acta Pediatr Scand 65
and the Swedish Medical Research Council (Project No. B76-13X-581-12B). We appreciate the help of Dr Tor Lindberg, Department of Pediatrics, Malmo General Hospital, who kindly referred some of the patients to us.
REFERENCES 1. Bumechy, Z . , Laxova, R. & Kamaryt, J.: Bemerkungen zur Mucoviscidosis im Kindesalter. Piidiatrie 8:99, 1969. 2 . Chernick, W. S.. Barbero, G. J. & Parkins, F. M.: Studies o n submaxillary saliva in cystic fibrosis. J Pediatr 59: 890, I96 l . 3. Chernick, W. S . , Eichel, H . J. & Barbero, G. J.: Submaxillary salivary enzymes as a measure of glandular activity in cystic fibrosis. J Pediatr 65: 694, 1964. 4. Danes, B. & Flensborg, E. W.: Cystic fibrosis: Cell culture studies on a Danish population. Am J Hum Genet23: 297. 1971. 5 . Davies, T . J.: A fast technique for the separation and detection of amylase isoenzyme using a chromogenic substrate. J Clin Pathof 25: 266, 1972. 6. Fanconi, G., Uehlinger, E. & Knauer, C . : Das Coeliakiesyndrom bei angeborener zystischer Pankreasfibromatose und Bronchiectasien. Wien Med Wochenschr, 86: 753, 1936. 7. Farber, S., Schwachmann, H . & Maddock, C.: Pancreatic function and disease in early life. J Clin Invest, 22: 827, 1943. 8. Gibson, L. E. & Cooke, R. E.: Test for concentration of electrolytes in sweat in cystic fibrosis of pancreas utilizing pilocarpine by iontophoresis. Pediatrics, 23: 545, 1959. 9. Gillard, B. K.: The influence of hydroxyamines on aamylase activity relative to their effect on ciliostasis in cystic fibrosis. National Cystic Fibrosis Research Foundation, Research Grant 197475. Cystic Fibrosis, quarterly annotated references, 12: 42, 1973. 0. Hadorn, B . , Johansen, P. G. & Anderson, C. M.: Exocrine pancreatic function in cystic fibrosis. In Lawson, D. (ed.): Proceedings of the 5th International Cystic Fibrosis Conference. Cystic Fibrosis Research Trust, London 1969, p. 56. 1. van Husen, N., Dominick, H.-Chr., Gerlach, U. & Kamanabroo, D.: lsoenzyme der a-Amylase im Serum von Patienten mit Cystischer Fibrose. Z KIin Chem Klin Biochem, 12: 214, 1974. 12. Johanson, P. G., Anderson, C. M. & Hadorn, B.: Cystic fibrosis of the pancreas, a generalized disturbance of water and electrolyte movement in exocrine tissues. Lancet, II: 455, 1968. 13. Kollberg, H.: Cyszisk fibros i Sverige. Abstracts of Uppsala Dissertations from the faculty of Medicine 197, 1974. 14. Mangos, J. A,, McSherry, N. R. & Benke, I. J.: A sodium transport inhibitory factor in the saliva of patients with cystic fibrosis of the pancreas. Pediatr Res, 1:436, 1967. 15. Mandel, I . D . , Kuscher, A . , Denning, C. F . , Thompson, R. H. & Zegarelli, E. V.: Salivary studies in cysticfibrosis. Am J D i s Child, 113:431, 1967.
Serum isoamylases in cysticfibrosis 16. Nelson, T. E., Gillard, B. K. & Bishop, S. H.: Salivary a-amylase and the role of pol yamine binding to carbohydrases in cystic fibrosis ciliostasis. Cystic Fibrosis Club Abstracts, Fifteenth Annual Meeting, Washington, D.C. 1974, p. 7. 17. Rosalki, S.: A direct staining technique for amylase isoenzyme determination. J Clin Pathol, 23: 373, 1970. 18. Rossiter, M., Barrowman, J. A., Daud, A. & Wharton, B. A.: Amylase content of mixed saliva in children. Acta Paediatr Scand, 63: 389, 1974. 19. di Sant'Agnese, P. A,: Clinical findings and research in cystic fibrosis. Mod Probl Pediatr, 10: 10, 1967. 20. di Sant'Agnese, P. A,, Grossman, H., Darling, R. & Denning, C. R.: Saliva, tears and duodenal contents in cystic fibrosis of the pancreas. Pediatrics, 22: 507, 1958. 21. di Sant'Agnese, P. A. & Talamo. R. C.: Pathogenesis and physiopathology of cystic fibrosis of the pancreas. N Engl J Med, 277: 1287, 1967. 22. di Sant'Agnese, P. A. & Vidaurretta, A. M.: Cystic fibrosis of the pancreas. JAMA, 172: 2065, 1960.
149
23. Skude, G.: Electrophoretic separation detection and variation of amylase isoenzymes. Scand J Clin Lab Invest, 35:41, 1975. 24. Skude, G.: Sources of the serum isoamylases and their normal range of variation with age. Scand J Gastroenterol, 10: 577, 1975. 25. Skude, G.: Unpublished data. 26. Skude, G. & Rothman, U.: Amylase isoenzymes in serum after maxillo-facial surgery. Scand J Plast Reconstr Surg, 7: 105, 1973. 27. Taussig, L., W-olf, R., Woods, R . & Deckelbaum, R.: Use of serum amylase isoenzymes in evaluation of pancreatic function. Pediatrics, 54: 229, 1974.
Submitted June 19, 1975 Accepted Nov. 10, 1975
(G. S.) Department of Clinical Chemistry Malmo General Hospital 21401 Malmo Sweden
Acta Pediatr Scand 65
SERUM ISOAMYLASES I N CYSTIC FIBROSIS G . SKUDE and H . KOLLBERG From the Department of Clinical Chemistry, Unirzersiry of Lund, Malmo General Hospital, S-21401 Malmo and the Department of Pediatrics, University of Uppsala, Uppsala, Su'eden
ABSTRACT. Skude, G. and Kollberg, H. (Department of Clinical Chemistry, University of Lund, Malmo General Hospital, Malmo and Department of Pediatrics, University of Uppsala, Uppsala, Sweden). Serum isoamylases in cystic flbrosis. Acta Paediatr Scand, 65: 145, 1976.Salivary and pancreatic isoamylases were determined in the sera of 33 patients with cystic fibrosis (CF) and in 34 CF-parents. Pancreatic serum isoamylase activities were greatly decreased in patients with CF, and only two values from this group fell within the normal range. Salivary isoamylases, however, were markedly increased so that the total serum amylase activities were normal. We interpret the low pancreatic isoamylase levels in serum to reflect reduced exocrine masses in the pancreas of CF-children. In heterozygotes, the mean activity of the pancreatic isoamylase was significantly higher than in the reference group, while salivary isoamylases were within the normal range. Due to a genetic polymorphism pancreatic isoamylase may occur in two main fractions. This variant type of pancreatic isoamylase appeared more frequently in CF-heterozygotes than was expected from a reference group of blood donors. KEY WORDS: Amylase, cystic fibrosis, genetic polymorphism, pancreatic isoamylase, salivary isoamylase
Exocrine secretions from the pancreas are markedly reduced in patients with cystic fibrosis (CF) (10, 21, 22), while the amylase contents of the saliva are reported variously as low, normal, or even increased (3, 15, 18, 20). Newly developed techniques have made possible the separation of the pancreatic and salivary isoamylases of serum ( 5 , 17, 23, 26). Decreased exocrine function of the pancreas may result in reduced pancreatic isoamylases in serum (23, 27). Recently pancreatic isoamylases have been reported low in a few patients with C F ( 1 1 , 23, 24, 27) while salivary isoamylases have been reported high (24). The exocrine functions of the pancreas and the salivary glands develop successively during infancy and early childhood (7, 18, 24). Thus children with cystic fibrosis n u s t be compared for isoamylases to normal children of corre-
sponding age. This paper reports the activities and patterns of pancreatic and salivary isoamylases in the sera of patients with C F and of CF-parents, who are obliged to be heterozygous for the CF-gene, as compared to agematched controls who were healthy. MATERIAL AND METHODS The material comprised, 33 patients with C F ( 1 5 males and 18 females including 3 sib pairs) whose ages ranged from 3 months to 28 years, and averaged 10.5 years (for details according to age see Fig. 1). All CF-patients had one or more typical clinical symptoms (30 had chronic pulmonary disease, 32 had nutritional problems and several had nasal polyposis, chronic sinusitis, cirrhosis of the liver, etc.). All patients had abnormally high sweat electrolytes as studied by the pilocarpine-iontophoresis method (8). Only one of the CF-patients did not require supplemental pancreatic enzyme therapy. The 34 CF-heterozygote subjects studied were parents (10 fathers and 24 mothers) of CF-patients. Their ages vaned from 24 to 55 years and averaged 37 ycars. Acla PrPdiatr Scand 6S
146
u/ 1 2 50
G . Skude and H . Kollberg S A L I V A RY AMYLASE
.
250
-
P A N C R EA T l C AMVLASE
150 -
2 00
200
... .. 1 so
100
100
50
50
0
0 CYSTIC F I B R O S I S
PARENTS
Fig. I . Activities of salivary isoamylase and of pancreatic
isoamylase in the sera of CF-patients and CF-parents. The solid line indicates the mean values for age-matched
AGE YEARS CYSTIC FIBROSIS
PARENTS
reference individuals while the hatched area indicates the range of normal values (mean plus and minus two standard deviations).
d.f.=91, pp>O.OOl]) (Fig. 1). The salivary isoamylase patterns in serum were entirely similar in all groups of patients studied. The pancreatic isoamylase patterns were not evident in most of the CF-patients because of low activities. Two children with C F exhibited clear patterns. One was homozygote for the most frequent genetic type of pancreatic isoamylase consisting of one main pancreatic fraction (23). The other was heterozygote at this locus and had two main pancreatic fractions (Fig. 2, sample c ) . Among the parents, 26 were homozygotes for the most frequent gene (Fig. 2. sampled), 7 were heterozygotes and one was homozygote for the variant gene (Fig. 2, sample e ) . In a series of 383 blood donors, the corresponding phenotype frequencies were 86.4, 12.3 and 1.3 %, respectively (25). Thus, the polymorphic variant gene appeared more frequently than expected in this small group of CF-parents (x2=3.16, d.f.= 1 ,p?O.O5).
DISCUSSION Finding total serum amylase activities normal in CF-patients accords with earlier reports ( 1 , 27). The distribution of isoamylases is markedly abnormal, however, because the pancreatic isoamylase is greatly reduced and the salivary isoamylase is markedly increased. These results agree with the results of Taussig and associates (27), who reported complete
a
b
C
d
e
Fig. 2. Serum isoamylase patterns (salivary, S , and pancreatic, P).Sample a: normal isoamylase pattern, activity 80+80 U/l. Sample b: typical pattern of C F activity 180+0 U/1. Sample c: CF, combined with heterozygosity for polymorphic pancreatic isoamylase gene, activity 150+50 U/I. Sampled: typical CF-heterozygosity, activity 7 0 f 140 U/1. Sample e: CF-heterozygosity and homozygosity for polymorphic pancreatic isoamylase gene, activity 85+50 U/I.
absence of the pancreatic isoamylases in 13 of 19 CF-patients studied, and found low activities in 4, and normal activities in 2. Our results conflict sharply with the report by v. Husen and associates ( 1 l ) , who found no salivary isoamylase in the sera of 13 CF-patients on study of 34 patients. This discrepancy might be explained by inadequate technique (starch-iodine staining). The marked decrease in pancreatic isoamylase activity in C F reflects the reduced mass of exocrine cells (6, 22, 23) in the pancreas. Supplemental pancreatic enzyme therapy does not affect serum amylase activity (25, 27). Abnormally high activities of pancreatic isoamylase in the sera of CF-heterozygotes have not been reported by others. The reason for this finding is unknown but it may reflect a disturbed exocrine function of the pancreas. An increased salivary isoamylase in the serum of CF-patients is confirmed in this study. We also report quantitative determinations of this isoamylase which have not previously been reported in these patients. The possibility, that this increase could be compensatory to the decreased pancreatic isoamylase seems unlikely. It may be that the Acta Pzdiatr Scand 65
148
G . Skude and H . Kollberg
salivary glands are also affected in CF, which would be in accordance with earlier observations (2, 14, 15) and in concert with the idea that CF is a generalized disease (4, 12, 19, 21 ). Observations that salivary isoamylases have ciliostatic properties (9, 16) could even suggest a central role for these enzymes in the pathogenesis of CF. The pancreatic isoamylase patterns in the CF-heterozygotes revealed an unusually high frequency of the gene associated with an additional slow migrating fraction. This gene was also present in one CF-patient, although pancreatic isoamylases were clearly visualized in only two. It is apparent that a larger number of CF-parents need to be studied. The present findings must be interpreted cautiously because of the small size of our group. The diagnosis of CF depends on the evaluation of clinical symptoms and of the interpretation of results from sweat electrolyte measurements by the pilocarpine iontophoresis method. There are, however, difficulties with the diagnosis in about one or two per cent of CF-children, who have sweat electrolytes within the normal limits. We propose the specific determination of serum isoamylases as a valuable diagnostic tool in CF. The characteristic pattern includes total serum amylase activities, which are normal or slightly increased, and pancreatic isoamylase activities which are markedly decreased. The activities of pancreatic isoarnylases do not develop normally during early childhood (24) so that decreased pancreatic isoamylase activities cannot be helpful diagnostically until after the age of three years. Even so, many children with CF remain undiagnosed beyond that age (13). The finding of high salivary isoamylase activity is suggestive of CF, but can never be considered diagnostic. ACKNOWLEDGEMENTS This investigation was supported by grants from the Medical Faculty, University of Lund, the Hierta-Retzius Foundation, the Swedish Society for Medical Research, Marcus Borgstroms Foundation, Sunnedahls Foundation, Acta Pediatr Scand 65
and the Swedish Medical Research Council (Project No. B76-13X-581-12B). We appreciate the help of Dr Tor Lindberg, Department of Pediatrics, Malmo General Hospital, who kindly referred some of the patients to us.
REFERENCES 1. Bumechy, Z . , Laxova, R. & Kamaryt, J.: Bemerkungen zur Mucoviscidosis im Kindesalter. Piidiatrie 8:99, 1969. 2 . Chernick, W. S.. Barbero, G. J. & Parkins, F. M.: Studies o n submaxillary saliva in cystic fibrosis. J Pediatr 59: 890, I96 l . 3. Chernick, W. S . , Eichel, H . J. & Barbero, G. J.: Submaxillary salivary enzymes as a measure of glandular activity in cystic fibrosis. J Pediatr 65: 694, 1964. 4. Danes, B. & Flensborg, E. W.: Cystic fibrosis: Cell culture studies on a Danish population. Am J Hum Genet23: 297. 1971. 5 . Davies, T . J.: A fast technique for the separation and detection of amylase isoenzyme using a chromogenic substrate. J Clin Pathof 25: 266, 1972. 6. Fanconi, G., Uehlinger, E. & Knauer, C . : Das Coeliakiesyndrom bei angeborener zystischer Pankreasfibromatose und Bronchiectasien. Wien Med Wochenschr, 86: 753, 1936. 7. Farber, S., Schwachmann, H . & Maddock, C.: Pancreatic function and disease in early life. J Clin Invest, 22: 827, 1943. 8. Gibson, L. E. & Cooke, R. E.: Test for concentration of electrolytes in sweat in cystic fibrosis of pancreas utilizing pilocarpine by iontophoresis. Pediatrics, 23: 545, 1959. 9. Gillard, B. K.: The influence of hydroxyamines on aamylase activity relative to their effect on ciliostasis in cystic fibrosis. National Cystic Fibrosis Research Foundation, Research Grant 197475. Cystic Fibrosis, quarterly annotated references, 12: 42, 1973. 0. Hadorn, B . , Johansen, P. G. & Anderson, C. M.: Exocrine pancreatic function in cystic fibrosis. In Lawson, D. (ed.): Proceedings of the 5th International Cystic Fibrosis Conference. Cystic Fibrosis Research Trust, London 1969, p. 56. 1. van Husen, N., Dominick, H.-Chr., Gerlach, U. & Kamanabroo, D.: lsoenzyme der a-Amylase im Serum von Patienten mit Cystischer Fibrose. Z KIin Chem Klin Biochem, 12: 214, 1974. 12. Johanson, P. G., Anderson, C. M. & Hadorn, B.: Cystic fibrosis of the pancreas, a generalized disturbance of water and electrolyte movement in exocrine tissues. Lancet, II: 455, 1968. 13. Kollberg, H.: Cyszisk fibros i Sverige. Abstracts of Uppsala Dissertations from the faculty of Medicine 197, 1974. 14. Mangos, J. A,, McSherry, N. R. & Benke, I. J.: A sodium transport inhibitory factor in the saliva of patients with cystic fibrosis of the pancreas. Pediatr Res, 1:436, 1967. 15. Mandel, I . D . , Kuscher, A . , Denning, C. F . , Thompson, R. H. & Zegarelli, E. V.: Salivary studies in cysticfibrosis. Am J D i s Child, 113:431, 1967.
Serum isoamylases in cysticfibrosis 16. Nelson, T. E., Gillard, B. K. & Bishop, S. H.: Salivary a-amylase and the role of pol yamine binding to carbohydrases in cystic fibrosis ciliostasis. Cystic Fibrosis Club Abstracts, Fifteenth Annual Meeting, Washington, D.C. 1974, p. 7. 17. Rosalki, S.: A direct staining technique for amylase isoenzyme determination. J Clin Pathol, 23: 373, 1970. 18. Rossiter, M., Barrowman, J. A., Daud, A. & Wharton, B. A.: Amylase content of mixed saliva in children. Acta Paediatr Scand, 63: 389, 1974. 19. di Sant'Agnese, P. A,: Clinical findings and research in cystic fibrosis. Mod Probl Pediatr, 10: 10, 1967. 20. di Sant'Agnese, P. A,, Grossman, H., Darling, R. & Denning, C. R.: Saliva, tears and duodenal contents in cystic fibrosis of the pancreas. Pediatrics, 22: 507, 1958. 21. di Sant'Agnese, P. A. & Talamo. R. C.: Pathogenesis and physiopathology of cystic fibrosis of the pancreas. N Engl J Med, 277: 1287, 1967. 22. di Sant'Agnese, P. A. & Vidaurretta, A. M.: Cystic fibrosis of the pancreas. JAMA, 172: 2065, 1960.
149
23. Skude, G.: Electrophoretic separation detection and variation of amylase isoenzymes. Scand J Clin Lab Invest, 35:41, 1975. 24. Skude, G.: Sources of the serum isoamylases and their normal range of variation with age. Scand J Gastroenterol, 10: 577, 1975. 25. Skude, G.: Unpublished data. 26. Skude, G. & Rothman, U.: Amylase isoenzymes in serum after maxillo-facial surgery. Scand J Plast Reconstr Surg, 7: 105, 1973. 27. Taussig, L., W-olf, R., Woods, R . & Deckelbaum, R.: Use of serum amylase isoenzymes in evaluation of pancreatic function. Pediatrics, 54: 229, 1974.
Submitted June 19, 1975 Accepted Nov. 10, 1975
(G. S.) Department of Clinical Chemistry Malmo General Hospital 21401 Malmo Sweden
Acta Pediatr Scand 65
