Masatoshi Ueda

Hyperamylasemia with Carcinoma of the Lung

Abstract Two patients with pronounced hyperamylasemia and hyperamylasuria, associated with metastatic carcinoma of the lung, are described. The primary lung tumor in the one patient with tissue ava...

Histological pancreatitis in end-stage renal disease

SummaryTo clarify a possible cause of hyperainylasemia in end-stage renal disease (ESRD), histological studies were performed on the pancreatic glands of twenty-seven autopsied patients with ESRD who had received long-term hemodialysis. The findings were compared with those in a similar number of age-matched control subiects. Histological evidence of pancreatitis was found in 51.9% of the ESRD patients as compared with 14.8% in the controls (p < 0.005). The pancreatitis was chronic in nature in 85.7% of the ESRD patients showing changes of pancreatitis. Secretin administration to an additional group of twelve patients with ESRD induced an elevation in the activities of both total and P-type serum amylase in only one patient. These findings suggest that although histological pancreatic alterations are common in patients with ESRD, they are probably not responsible for the P-type hyperamylasemia frequently found in such patients.

Ultracentrifugal characteristics of macroamylasemic serum

Abstract Sedimentation coefficients of the amylases present in the sera of 22 patients with macroamylasemia were measured by means of sucrose density gradient ultracentrifugation using beef liver catalase (11.3 S) and the 7 S serum proteins as markers. The sedimentation coefficients of the macroamylases in 18 of the cases ranged from 7.7 S to 10.7 S; in four cases the activity peaks were too broad to assign a definite sedimentation coefficient. One exceptional case (Case 6) exhibited two peaks of amylase activity: one had a sedimentation coefficient greater than the 19 S serum proteins and the other a coefficient of 10.7 S. The normal-size amylase component seen on dextran gel filtration was no longer discernible after ultracentrifugation in eight of the cases. These observations, in contrast to those on the paper electrophoretic pattern of those sera, suggest that the macroamylase complexes in patients with macroamylasemia are not homogeneous. The observations also indicate that dextran gel filtration may lead to erroneous concepts regarding the component fractions of serum amylase and their molecular sizes because of interaction between amylase and dextran.

Pancreatic-type hyperamylasemia in end-stage renal disease.

Pancreatic-type isoamylase (P-type) and salivary-type isoamylase (S-type) activities were determined by the wheat protein inhibitor method in 29 patients with end-stage renal disease and in 38 healthy volunteers. Serum levels of total amylase (322±43 units/liter) and P-type (212±39 units/liter) in ESRD were significantly higher than those of controls (total: 142±7 units/liter,P<0.01; P-type: 52±4 units/liter,P<0.01). There was no significant difference between S-type activities in ESRD (110±16 units/liter) and in controls (90±6 units/liter). The ratios of amylase clearance to creatinine clearance (Cam/Ccr) and S-type clearance to creatinine clearance (Cs-amy/Ccr) rose significantly in ESRD(Cam/Ccr: 5.7±0.6%; Cs-amy/Ccr: 4.3±0.55%) compared to controls (Cam/Ccr: 3.2±0.24%,P<0.01; Cs-amy/Ccr: 2.1±0.17%,P<0.01). The ratio of P-type clearance to creatinine clearance (Cp-amy/Ccr) revealed no significant difference between ESRD (5.5±0.54%) and controls (5.6±0.42%). The renal excretion of P-type appeared to be more impaired than that of S-type in ESRD.

Age and sex-dependent alterations of serum amylase and isoamylase levels in normal human adults

Total amylase and salivary-and pancreatic-type isoamylase levels were assayed in sera from 606 apparently healthy adults of different sex and age groups. There were significant differences in both total amylase and isoamylase levels, depending on age and sex, one of the characteristics being that levels of these three enzymes were significantly higher in the elderly group in both men and women than in other age groups. Another feature was that all of these enzyme levels were significantly greater in women in the third and fourth decade than in men. Age and sex differences should be taken into consideration in the evaluation of mild hyperamylasemia.

Macroamylasemia: Variation in the Response of the Macroamylase Complex to Acidification

Summary Acidification had a variable effect on the integrity of the large amylase component in the sera of 21 patients with macro-amylasemia. Reduction of pH to 3.4 resulted in complete dissociation of the macroamylase in 13 cases; partial dissociation occurred in six while two remained unchanged. The response to acidification could be correlated with the sedimentation coefficients of the complexes: macroamylases with the highest coefficients tended not to be affected by acidification; those with the lowest values tended to be completely dissociated, while those with intermediate values tended to be partially dissociated. The variable response to lowering of the pH provides further evidence pointing to heterogeneity of the macroamylase complexes.