Simplified chromatographic method for isoamylase analysis.

A simplified and relatively rapidly performed chromatographic method for measuring the principal isoamylases in serum and urine has been developed. It is hoped that this method may help make isoamylase analysis more readily applicable in the ordinary clinical setting.

New dimensions in the laboratory diagnosis of pancreatic disease.

The laboratory diagnosis of pancreatic disease has been made more precise by certain modifications in older methods and by the introduction of a variety of new technical procedures. The principal human isoamylases may now be distinguished and their activities in serum and urine measured. A test has been devised which helps indicate the presence of acute pancreatitis by showing relatively increased excretion of amylase in the urine as compared with creatinine. The ratio of amylase to creatinine in the urine appears to be a good index of relative hyperamylasuria. A screening test for pancreatic-type hyperamylasuria has been formulated that allows increased urinary excretion of this isoamylase to be identified. These additions and developments have sharpened the interpretation of hyperamylasemia and hyperamylasuria and have added new dimensions to the laboratory diagnosis of pancreatic disease.

Constipation of prolonged duration.

A case is reported of a 19-year old man who went periods of four and a half and four months without a bowel movement and who experienced no distress throughout these periods except for late appearing abdominal cramps.

Clinical application of amylase isoenzyme analysis.

Amylase isoenzyme analysis of serum, urine and other bodily fluids using dextran gel and ion exchange chromatography provides a new dimension in the identification of pancreatic disease. Examples are described that illustrate the clinical application of such analysis and the usefulness of the information that may be derived.

Simulation of macroamylasaemia by salivary-type ('S type') hyperamylasaemia.

Hyperamylasaemia with low or normal urinary amylase excretion in the face of normal renal function has been noted to be indirect evidence for the existence of macroamylasaemia. A more refined indicator is a low ratio of renal amylase clearance to creatinine clearance. This report describes observations made in three patients, each of whom displayed the indirect features suggestive of macroamylasaemia. In none of these patients, however, could a serum macroamylase be demonstrated by chromatography. Ultracentrifugation was also done in one of the patients and likewise failed to disclose a macroamylase in the serum. When the isozyme nature of the serum amylase in each of these patients was examined, there was found to be a marked rise in activity of the salivary-type isoamylase (;S-type amylase'). The pancreatic-type isoamylase (;P-type amylase') was normal in one patient and perhaps slightly above normal in the other two. These data indicate that (1) S-type hyperamylasaemia may exhibit the indirect criteria taken to indicate macroamylasaemia and thereby simulate the latter disorder; and (2) unequivocal identification of macroamylasaemia requires the direct demonstration of the presence in the serum of a macromolecular amylase complex.

Unusual isomaylase in cancer-associated hyperamylasemia.

Hyperamylasemia and hyperamylasuria were found in two patients with carcinoma of the pancreas and in two other patients with carcinoma of the lung. Detailed isoamylase analyses were conducted on the serum amylase of three and the urine amylase of all four of these patients, using a modified chromatographic procedure. The studies demonstrated the existence, in one of the lung cancer patients and in one of the patients with pancreatic cancer, of an unusual component of amylase given the designation "Y." This component had also been noted in some human milk samples. In one of the lung cancer patients, an isoamylase was found in the serum and urine after radiation treatment that was close to but not identical to the Y isoamylase in chromatographic position. Although a relationship of isoamylase component Y to generating tissue is suggested by these findings, such a relationship of isoamylase component Y to generating tissue is suggested by these findings, such a relationship remains to be proven.

Tumor-associated hyperamylasemia.

Studies were made in eight patients with hyperamylasemia associated with cancer of the lung, pancreas or colon. Isoamylase analysis, conducted in seven of the eight patients revealed that the dominant isoamylase component was S-type in three and P-type in three; in one patient both isoamylases were elevated about equally. Examination of the serum or urine of the same seven patients for subcomponent isoamylase disclosed the presence in two of the seven of an unusual isoamylase designated "Y-type". This subcomponent isoamylase was also found in some samples of human milk, but not in normal persons or in patients with a variety of disorders other than cancer. The significance of hyperamylasemia occurring in association with cancers, the factors responsible for the variability in isoamylase pattern in those with hyperamylasemia, and the relationship, if any, of the "Y" isoamylase form to cellular growth and replication are all presently obscure and remain to be elucidated.

Serum amylase changes during pregnancy.

Study of the behavior of serum amylase activity in 200 preganant women in various stages of pregnancy indicated that: (1) serum amylase rises gradually during pregnancy until the twenty-fifth week and thereafter falls slightly; (2) serum amylase values may be found in normal pregnant women during the second and third trimesters that exceed those in normal men and nonpregnant women; (3) during the second trimester of pregnancy there may be an alteration in the relative distribution of the pancreatic and salivary-type isoamylases with the salivary type tending to dominate. Knowledge of these changes is of importance in the clinical assessment of serum amylase values in pregnant women complaining of abdominal pain and other symptoms suggestive of complicating acute pancreatitis. An explanation for the observed changes is not readily available and further study is required.