Alkaline phosphatase synthesis and properties of subcellular organelles during in vitro culture of jejunal biopsies from control subjects and patients with coeliac disease.

Portions of jejunal biopsies from control subjects and from patients with coeliac disease were cultured for 24 hours using an in vitro organ culture technique. Alkaline phosphatase activity was measured in the tissue and medium before and after culture; enzyme activities were expressed per microgram tissue DNA. The increase in enzyme activity during the culture period was taken to represent net enzyme synthesis. Alkaline phosphatase synthesis by mucosa from patients with untreated gluten-sensitive coeliac disease and by mucosa from patients with non-responsive coeliac disease was significantly less than that by normal mucosa. Alkaline phosphatase synthesis by mucosa from patients with treated gluten-sensitive coeliac disease was greater than that by untreated coeliac mucosa but was less than normal mucosa. Sequential studies of alkaline phosphatase synthesis by jejunal mucosa from seven patients with coeliac disease, before and after successful treatment by gluten withdrawal, showed an increase in synthesis in all patients. Study, by analytical subcellular fractionation with sucrose density gradient centrifugation, of the properties of the organelles of cultured control tissue showed good preservation of their integrity. A striking finding, however, was the decrease in malate dehydrogenase with a corresponding marked increase in lactate dehydrogenase. This would be expected to be followed by a shift from aerobic to anaerobic metabolism. Analytical subcellular fractionation of cultured mucosa from patients with coeliac disease gave similar conclusions. There was, however, a marked improvement of the brush border abnormalities, characteristic of coeliac disease, during culture with increased enzyme activities and membrane equilibrium density in the sucrose gradients.

Intestinal clearance of alpha 1-antitrypsin. A sensitive method for the detection of protein-losing enteropathy.

Gastrointestinal loss of plasma is usually measured with radiolabeled macromolecules. These methods are expensive and cumbersome. The use of alpha 1-antitrypsin as an endogenous marker and the determination of alpha 1-antitrypsin fecal clearance enable the diagnosis of protein-losing enteropathy. alpha 1-Antitrypsin is measured in feces and blood by radial immunodiffusion, and the results are expressed as clearance. There is a significant correlation between alpha 1-antitrypsin fecal clearance and 51Cr-plasma protein clearance (r = 0.96, p less than 0.001). The sensibility of alpha 1-antitrypsin test compared to [51Cr] is 93.3%, the specificity is 90%. The positive predictive value is 97.7%, the negative predictive value 75%. We found no alpha 1-antitrypsin in gastric juice of pH below 3. In vitro studies confirmed the destruction of alpha 1-antitrypsin in gastric juice of pH below 3. There is a slight decrease of alpha 1-antitrypsin concentration when stools are incubated at 37 degrees C. In duodenal juice there is a small lessening of alpha 1-antitrypsin concentration after an incubation at 37 degrees C for 1 h. In conclusion, the fecal clearance of alpha 1-antitrypsin seems to be an inexpensive and quite reliable test of protein-losing enteropathy.

Protein synthesis by cultured jejunal mucosa from control subjects and patients with coeliac disease.

Jejunal biopsies from patients with coeliac disease and from controls were cultured in vitro for 24 hours with 14C-labelled leucine. The net rate of protein synthesis was found to be linear over 24 hours for mucosa from control subjects and patients with coeliac disease. Protein synthesis by mucosa from untreated coeliac patients was significantly greater than by control mucosa. Protein synthesis by treated gluten-sensitive coeliac mucosa was significantly less than that by untreated coeliac mucosa and did not differ from control mucosa. Protein synthesis by treated non-responsive coeliac mucosa was significantly less than untreated coeliac mucosa but greater than control mucosa. The differences in protein synthesis could not be accounted for by differences in the size of the enterocyte leucine pool. Analytical subcellular fractionation of cultured jejunal mucosa showed that most of the protein synthesised in vitro was found in the cytosol and endoplasmic reticulum-brush border fractions of the enterocyte.

Increased cell loss in the human jejunum induced by laxatives (ricinoleic acid, dioctyl sodium sulphosuccinate, magnesium sulphate, bile salts).

Two conjugated bile salts (10 mmol/l sodium glycocholate, 10 mmol/l sodium taurodeoxycholate) and three laxatives (30 mmol/l magnesium sulphate, 10 mmol/l ricinoleic acid, 2 mmol/l dioctyl sodium sulphosuccinate) were tested on seven subjects with no intestinal lesions in 14 experiments by intestinal perfusion of the jejunum. A 25 cm segment was studied. Each solution was perfused at the rate of 10 ml/min. Water and electrolyte fluxes, losses of deoxyribonucleic acid (DNA), and intestinal cell enzyme activity were measured in the fluids collected. All the laxatives and bile salts tested (except sodium glycocholate) induced water and electrolyte secretion, a rise in intraluminal DNA loss, and enzyme activity. It was possible to establish a significant correlation (p less than 0.001) between the amounts of water fluxes and DNA loss under the effect of dioctyl sodium sulphosuccinate and ricinoleic acid.

[Intestinal clearance of alpha 1 anti-trypsin: a simple technique for diagnosis of protein losing enteropathy (author's transl)]. / Clairance intestinale de l'alpha 1. anti-trypsine: une technique simple de diagnostic des entéropathies exsudatives.

Until recently, to diagnose exsudative enteropathy required the use of radio-isotopes and a stay of several days in hospital. Alpha-1-antitrypsin can now be used as endogenous plasma marker and assayed in the serum and faeces by a simple immunochemical method, thus measuring its intestinal clearance. Fifteen healthy subjects and 13 patients with organic digestive diseases were investigated by this method. The mean clearance values were inferior to 10 ml/24 h in the control group and significantly higher in the patients' group. Digestive protein loss can therefore be diagnosed by the new method, which offers the additional advantages of being reliable, easy, relatively inexpensive and applicable to out-patients.

Diagnosis of protein-losing enteropathy by gastrointestinal clearance of alpha1-antitrypsin.

Alpha1-antitrypsin was assessed, in 10 patients with protein-losing enteropathy and 13 control subjects, as an endogenous marker of plasma-protein loss into the gastrointestinal tract. Both faecal alpha1-A.T. concentrations and faecal alpha1-A.T. clearance were significantly higher in patients than in controls. Wtih clearance there was no overlap between the groups. Over 10 days the normal gastrointestinal clearance of alpha1-A.T. was 3.07 +/- 2.25 (S.D.) ml/day. Measurement of alpha1-A.T. clearance is easy and requires no radioisotopes.

Metiamide treatment in five patients with Zollinger-Ellison syndrome.

Five patients with Zollinger-Ellison syndrome received metiamide per os in doses ranging from 600 to 1,200 mg/day for a minimum period of 2 weeks. Drug produced an inhibition of basal gastric acid secretion ranging from 5 to 100% with relief of symptoms. Survey of patients during and after metiamide course showed sometimes a prolonged antisecretory effect up to 26 days after the end of treatment or, on the contrary, a reduced drug activity in spite of increasing doses.

Biochemical and morphological studies on human jejunal mucosa maintained in culture.

1. The combination of a wire-mesh support with the roller-tube technique is described as a procedure for the culture of human jejunal mucosa in vitro. 2. The technique has been applied to fragments (approximately 10 mg) of jejunal biopsies from both normal subjects and patients with coeliac disease. 3. The cultured tissue has been shown by radio-autography to incorporate [3H]leucine into proteins of the villus epithelial cells and [3H]thymidine into nucleic acid, predominantly by the enteroblasts. 4. Although the tissue protein DNA contents fall during culture, it was found that the combined tissue and medium DNA content remained constant during culture and may be used as a reference for enzyme and biochemical studies on cultured intestinal biopsies.