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Biomedical subjects

P Fric

Publications and source records attributed to P Fric.

At least 91 records · Page 5Linked to original sources
PubMed1982

[Pancreatic maldigestion and malabsorption].

Pancreatic maldigestion is due to decreased intraluminal hydrolysis of foodstuffs which is the consequence of lowered concentration of pancreatic enzymes. This if caused by insufficient secretion, absent activation or increased inactivation so pancreatic enzymes in the intestinal lumen. In most cases maldigestion is a late syndrome in diseases of the pancreas because of its extensive functional reserve. The diagnosis of pancreatic maldigestion is relatively simple. The replacement therapy with pancreatic enzymes gives satisfactory results in most subjects. The substitution of other substances (vitamins, calcium) is carried out according to similar lines as in malabsorption of other etiology. In addition to foodstuffs digestion some other assimilation functions of the pancreas have been recognized recently. These may be of considerable importance for the integrated course of the digestive-absorptive processes.

Absorption↗
PubMed1980

Endopeptidase of the brush border membrane of rat enterocyte. Separation from aminopeptidase and partial characterization.

The brush border of the enterocytes of the rat was isolated by the method of differential centrifugation with CaCl2 according to Schmitz. This material was solubilized with papain, trypsin and Triton X-100. The greatest amount of membrane enzymes was released to the supernatant (105 000 X g) with the use of Triton X-100. The tritonized supernatant was treated in the next step by papain, bromelain, ficin and trypsin (individually or in combinations). After simultaneous proteolysis with papain and bromelain a partial separation of the aminopeptidase from the endopeptidase by Sephadex G-200 chromatography was observed. These two enzyme activities were distinctly separated by isoelectric focusing at pH 4--6. Two enzymatically active bands (RF 0.13 and 0.24) in the aminopeptidase fraction and one single active band (RF 0.16) in the endopeptidase fraction using polyacrylamide gel electrophoresis were found. Co-migrating proteins to all of these activities were detected. Endopeptidase activity splits 3-carboxypropionyltrialanin-4-nitroanilide (SucAla3NAp) in the position P2-P1. Liberated aminoacyl-NAP may be further split to generate chromogenic 4-nitroaniline through aminopeptidase activity. Endopeptidase of the brush border of the rat enterocytes is characterized by the following properties: 1) molecular mass 130000 +/- 15 000 dalton; 2) Km value (substrate: SucAla3NAp) 1.1 X 10(-3) M; 3) pI 5.23; 4) ph optimum 8.5; 5) 50% activity remains after 15 min of preincubation at 50 degrees C; 6) activity is strongly inhibited by EDTA, p-chloromercuribenzoate, Mn2 and Co2.

Aminopeptidases↗
PubMed1980

A new method of testing pancreatin therapy in vivo by the use of a peroral chymotrypsin substrate 4-(N-acetyl-L-tyrosyl)aminobenzoic acid.

The efficacy of pancreatin in vivo was determined in 14 patients with advanced pancreatic insufficiency using a peroral test with 2 g of chymotrypsin substrate, 4-(N-acetyl-L-tyrosyl)aminobenzoic acid, the Lundh test meal and 1000 ml tea. Chymotrypsin hydrolysis was quantified by 4-aminobenzoic acid excreted in 6-hr or 8-hr urine samples. After a control test without pancreatin, one or two tablets of Panpur (Nordmark-700 mg of pancreatin and 50 mg of bile per tablet) were applied simultaneously with the Lundh meal on repeated examinations. The urinary excretion of 4-aminobenzoic acid was restored to normal values in 5 subjects during both sampling periods. With this method, stimulated and substituted chymotrypsin is measured at the same time. The conditions of the tests, both with and without pancreatin replacement, are fully comparable and thus the significance of factors modifying the activity of enzymic components in the digestive tube is limited. The method appears appropriate for the institution of an effect pancreatin therapy and its control in vivo.

4-Aminobenzoic Acid↗
PubMed1980

[Developments in the laboratory diagnosis of diseases of the exocrine pancreas (author's transl)].

Laboratory tests are the object of continuous interest in acute as well as chronic pancreatic disease. Enzymic assays play an important role, particularly in screening for pancreatic disease. The diagnostic contribution of amylase, isoamylases, immunoreactive trypsin and lactoferrin, ribonuclease and galactosyltransferase, as well as the problem of chronic nonpancreatic hyperamylasemia is reviewed. Functional methods detect a normal or abnormal function and in this sense the results should be interpreted. Present evaluation of the pancreozymin-secretin test, the Lundh test, fecal chymotrypsin, determination of stimulated chymotrypsin secretion by peroral synthetic substrates marked with 4-aminobenzoic acid, duodenal excretion of 75Se-methionine and plasma pancreatic polypeptide is given. Up to now, immunologic methods have not fulfilled the expectations in spite of considerable attention paid to them in recent years.

Humans↗
PubMed1978

Functional examination of the pancreatic secretion with 4-(n-acetyl-l-tyrosyl)aminobenzoic acid.

The oral dose of 2g 4-(N-acetyl-L-tyrosyl) aminobenzoic acid was used to establish the secretion of pancreatic chymotrypsin after stimulation with Lundh's test-meal in 45 persons. By action of chymotrypsin 4-aminobenzoic acid is split in the small intestine. The extent of its excretion in the urine serves as an indicator of exocrine pancreatic secretion. The 4-aminobenzoic acid in the urine is estimated after acid hydrolysis by the diazotation reaction. The average value (x +/- SE) of 4-aminobenzoic acid excreted in an 8-hr urine sample amounts to 69.4 +/- 3.0% with the lower limit of the normal values (x - 2 SD) 49.6%. The corresponding values in patients with pancreatic maldigestion were significantly decreased (25.1 +/- 3.6%). Reduction of the collection period of urine to 6 hrs is sufficient for the demonstration of more advanced forms of pancreatic insufficiency. In cases of disturbances of absorption in the small intestine an extension of the urine collection period to 8 hrs is recommended. We consider this oral test to be a suitable screening method which can be conveniently used in out-patient practice.

4-Aminobenzoic Acid↗