Three methods compared for determination of pancreatic and salivary amylase activity in serum of cystic fibrosis patients.

We evaluated three methods for serum amylase (EC 3.2.1.1) isoenzymes to determine whether they are interchangeable and to test their ability to discriminate between cystic fibrosis patients with and without pancreatic insufficiency. One method involved salivary amylase inhibitor (O), and two were polyacrylamide gel electrophoresis separations differing in method of detection--either direct zymogram (G) or gel slicing followed by activity estimates per slice (W). Results for percentage pancreatic amylase differed significantly. Reproducibility for percentage pancreatic amylase was high, moderate, and low (r = 0.95, 0.53, and 0.02) for methods G, O, and W, respectively; moderate (r = 0.60) among the three methods; and moderate between pairs. Therefore, this result for a subject must be considered relative to the method used in its determination. The clinical diagnosis of pancreatic insufficiency was verified by 77.8%, 83.3%, and 94.4% correct classification rates for methods O, W, and G, respectively. Evidently, method G is the most efficient and may be the method of choice for measuring serum amylase isoenzymes in cystic fibrosis.

Diagnostic and therapeutic applications of bentiromide screening test for exocrine pancreatic insufficiency in patients with cystic fibrosis. Comparison with other tests of exocrine pancreatic disease.

The bentiromide test for exocrine pancreatic function was carried out in normal volunteers, patients with cystic fibrosis (CF) without clinical evidence of pancreatic dysfunction, and CF patients with clinically significant exocrine pancreatic insufficiency. The test was performed with and without the concomitant administration of a Lundh test meal. p-Aminobenzoic acid was given on a separate occasion to eliminate false positives due to factors unrelated to pancreatic disease. Correct classification of 25 CF patients with pancreatic insufficiency and 9 CF patients without clinical pancreatic dysfunction was possible by interpreting the results of the above three tests. Isoamylase determinations would have misclassified 20% of the CF patients with pancreatic insufficiency, but were able to detect the CF patients without clinical pancreatic dysfunction on the basis of an elevated pancreatic amylase isoenzyme. The bentiromide test results were normal in CF patients without clinical pancreatic dysfunction despite previous findings of decreased bicarbonate secretion in this group. However, the bentiromide test did appear to be useful in the evaluation of therapeutic intervention with exogenous pancreatic enzymes and other adjunctive therapy.

Lysozyme determination in parotid saliva from patients with Sjögren's syndrome.

Lysozyme and total protein concentrations in parotid saliva were measured in 17 patients with primary Sjögren's syndrome, in six patients with Sjögren's syndrome secondary to hyperlipoproteinemia and in 14 age- and sex-matched healthy control subjects. Increased lysozyme concentrations were found only in patients with primary Sjögren's syndrome and correlated well with the presence of parotid gland enlargement. The total protein concentration in the saliva of patients with Sjögren's syndrome was not different from that of the control subjects. Parotid saliva lysozyme determination may be useful as an early adjunctive diagnostic test of primary Sjögren's syndrome.

Correlative histologic and serologic findings of sicca syndrome in patients with systemic lupus erythematosus.

We prospectively evaluated 24 patients with systemic lupus erythematosus for clinical, histologic, and serologic evidence of sicca syndrome. Abnormalties suggestive of sicca syndrome in patients with systemic lupus were identified by parotid scan (58%), questionnaire (54%), labial biopsy (50%), Schirmer's test (21%), and parotid flow rate (13%). An increased frequency of autoantibodies to gamma globulin and cellular antigen SS-A was detected in lupus patients with histologic changes on labial biopsy. The serologic findings are similar to those of patients with sicca syndrome alone with the exception of the reduced incidence of anti-SS-B in patients with systemic lupus.

Elevated serum amylase activity in the absence of clinical pancreatic or salivary gland disease: possible role of acute hypoxemia.

Elevated serum amylase activity, in the absence of clinically apparent pancreatic or salivary gland disease, has been observed in many seemingly unrelated conditions. In a search for common etiological factors to account for hyperamylasemia in these conditions, a retrospective analysis was performed. Eighty-four episodes of hyperamylasemia (greater than 300 I.U./l. Phadebas method) occurring in 75 patients over a one-year period ending in June, 1975 were assigned to one of two groups. Group 1 consisted of 56 (67%) episodes of hyperamylasemia with clinical pancreatitis. Group 2 consisted of 28 (33%) episodes of hyperamylasemia in the absence of clinical pancreatitis. Hypoxemia (pO2 less than 75 mm. Hg.) was found in 9/15 patients in Group 2 who had arterial blood gases measured. To assess the possible relationship between acute hypoxemia and amylase activity, a prospective study was initiated. Patients with known causes of pancreatitis or renal failure were eliminated. Hyperamylasemia was found in 3/8 hypoxemic patients. This raises the possibility that acute hypoxemia alone or in combination with other factors may raise serum amylase activity, possibly through ischemic injury to the pancreas or salivary glands or other amylase containing tissues.

Fractionation of human parotid saliva proteins.

A chromatographic procedure for purification of the proteins in human parotid saliva has been developed. The eluates of a Sephadex G-150 and two ion exchange columns have been analyzed simultaneously by several physical and chemical tests; these include three optical properties of proteins, assays for neutral sugars, sialic acid and zinc, and disc gel electrophoresis. The ratios of the different variables have been used to determine the homogeneity and complexity of the protein distribution in the various peaks of the chromatographic eluates. By chromatographic methods, it has been possible to purify a glycoprotein with unusual staining characteristics and amino acid composition. Glycoproteins with similar properties comprise a major portion of the proteins in parotid saliva and appear to constitute a family of related proteins which differ in molecular size, carbohydrate and sialic acid content, and electrophoretic mobility. The fractionation of several enzymes in parotid saliva is also reported.

Sjögren-type syndrome after allogeneic bone-marrow transplantation.

Four patients, treated for hematologic disorders with bone-marrow transplants from HLA-identical siblings, spontaneously complained of dry eyes 8 to 12 months after transplantation. Four allograft recipients and two recipients of autologous bone-marrow transplants were evaluated for xerophthalmia and xerostomia. Three allogeneic marrow recipients had evidence of keratoconjunctivitis sicca, and two had decreased parotid gland function. All four allograft recipients had minor salivary gland histopathology identical to that of Sjögren's syndrome. The severity of symptoms and histologic lesions corresponded with the severity of chronic graft-versus-host disease. In addition, one patient developed sclerodermatous skin changes, another had discoid lupus erythematosus, and two patients had laboratory evidence of cholestasis. None of the patients had autoantibodies but all had hypergammaglobulinemia. In contrast, none of the recipients of autologous bone marrow had clinical, laboratory, or histologic findings resembling Sjögren's syndrome.

Possible mechanisms of normal amylase activity in hyperlipemic pancreatitis.

Lipemic serum from three patients with acute pancreatitis and type IV hyperlipemia was fractionated into very-low-density lipoproteins and clear serum. Amylase activity (determined by the Phadebas method) in the component fractions did not exceed that in the original lipemic serum. Addition of these fractions or VLDL and chylomicrons from asymptomatic patients with hyperlipemia to nonlipemic serum from patients with "routine acute pancreatitis" did not inhibit amylase activity or alter the electrophoretic mobility of amylase isoenzymes. Therefore the normal amylase activity often observed in hyperlipemic pancreatitis does not result from an inhibition of amylase activity by serum lipoproteins.

Changes in serum salivary isoamylases in Sjögren's Syndrome.

Quantitative polyacrylamide disk gel electrophoresis of sera from 27 patients with Sjögren's syndrome (SS) and 12 comparable normal subjects revealed that serum amylase activity in patients with SS varies due to changes in the salivary isoenzyme, while pancreatic isoamylase remains normal. The SS group can be divided into those patients with markedly increased salivary isoamylase and those with normal or low salivary isoamylase. At this time we cannot be certain whether this reflects different stages in a progressive disorder, or differences in the underlying pathologic processes. Analysis of amylase isoenzymes in serum previously has been shown to be of value in pancreatic disorders, and we have now demonstrated that changes in the salivary glands may also be relected in serum amylase isoenzymes. Study of patients with other salivary and pancreatic disorders will be needed to define the clinical utility of amylase isoenzyme analysis.

Quantitative evaluation of serum pancreatic isoamylases in cystic fibrosis.

The amylase in sera of 20 patients with cystic fibrosis of the pancreas (CFP), 17 of whom had pancreatic insufficiency (PI), and of 34 normal control subjects was separated into its pancreatic and salivary components and quantitated. Electrophoretic separation was achieved on polyacrylamide disc gels with subsequent sectioning of the gel columns. The amylase content in international units per liter (IU/L.) was obtained for each section by the insoluble blue starch substrate method. The mean total serum amylase of the CFP patients with PI was significantly lower than the control group. A highly significant decrease was found when the pancreatic isoamylase was considered alone. The salivary isoamylase level remained essentially the same. Three patients with CFP but without PI demonstrated higher than normal pancreatic amylase values in the serum. These patients may be in an early stage of a progressive involvement of the pancreas in which there is an increased release of amylase. This method of electrophoretic separation and quantitation of the serum amylase is sensitive and efficient and allows the simultaneous processing of multiple specimens. The results obtained agree with previously published ratios of serum isoamylases. Our method should be valuable in the study of other diseases of the exocrine pancreas and salivary glands.

Estimation of zinc concentration of parotid saliva by flameless atomic absorption spectrophotometry in normal subjects and in patients with idiopathic hypogeusia.

The concentraiton of zinc in parotid saliva was estimated by flameless atomic absorption spectrophotometry. As small a sample as 5 to 10 mul of whole paratid saliva can be analyzed quickly and reliably, without special sample handling and with littleinterference from other ions normally found in saliva. Parotid salivary zinc concentration in 34 subjects with normal taste acuity was 51 plus or minus 14 ppb(parts per billion)(mean plus or minus 1 S.D.); parotid salivary zinc concentration in 47 subjectswith idiopathic hypogeusia was 10 plus or minus 6 ppb (mean plus or minus 1 S.D.) which is significantly lower than that in normal subjects (p lessthan 0.001). This technique is a usual method by which to evaluate parotid salivary zinc, particulary inrelationship to problems of taste, appetite, and nutrition.

Pharyngeal lipase and digestion of dietary triglyceride in man.

Lipolytic activity was studied in esophageal and gastric aspirates obtained with a nasogastric tube from 14 healthy adult subjects. Samples were collected from esophagus, first at 30-35 cm and then at 40-45 cm from the nose, as the subject, after drinking 15-30 ml of a cream-milk mixture, swallowed small amounts of water. The samples from stomach were taken last and usually contained a small amount of cream-milk mixture. Lipolytic activity was assayed using chylomicron, milk, and corn oil triglyceride as substrate. Esophageal and gastric samples both contained lipolytic activity which hydrolyzed long-chain triglyceride to diglyceride, monoglyceride, and FFTA, had a pH optimum of 5.4, and was not affected by either had a pH optimum of 5.4, and was not affected by either 0.5 M NaCl or 4 mM sodium taurodexycholate. The activity, expressed as nanomoles of chylomicron triglyceride hydrolyzed per milliter per minute, ranged from 0 to 145 in upper esophageal, 5 to 303 in lower esophageal, and 50 to 357 in gastric samples. Only a trace of lipolytic activity was found at pH 5.4 in saliva collected from the parotid, submandibular, and sublingual glands, thus excluding those tissues as a source of the activity found in esophageal and gastric aspirates. The findings suggest that in man glands in or near the pharynx secrete a lipase that acts in the stomach to hydrolyze long-chain triglyceride to partial glycerides and FFA. It is proposed this reaction is the first step in the digestion of dietary fat and that the amphiphilic lipids formed by lipolysis facilitate the emulsification of triglyceride in the stomach.