PubMed Health⌕ Search

Biomedical subjects

B Hadorn

Publications and source records attributed to B Hadorn.

At least 37 records · Page 2Linked to original sources
PubMed1977

Biosynthesis of brush border glycoproteins by human small intestinal mucosa in organ culture.

The incorporation of [14C]glucosamine into brush border glycoproteins by human small intestinal mucosa in organ culture has been investigated. The experiments were based on the observations that (1) isolated brush border membrane fragments from cultured explants showed an unchanged pattern of protein bands and brush border enzyme activities on sodium dodecyl sulfate/polyacrylamide gels after electrophoresis and (2) the rate of overall [14C]glucosamine incorporation measured in the tissue homogenate remained constant up to 48 h. After 24 h of culture, the radioactivity peaks on gels due to incorporation of [14C]glucosamine were found exclusively in the high molecular weight region and corresponded to protein bands identified as maltase-glucoamylase, lactase, sucrase-isomaltase, enterokinase and alkaline phosphatase. Enzymatic activity could not be assigned to the three remaining labelled bands. Most of these glycoproteins were already labelled after 5 h. Newly glycosylated brush border enzymes remained predominantly associated with the brush border membrane of intact cells with little release into the medium up to 24 h.

Cell Membrane↗
PubMed1977

Glycosidases of the guinea pig brush border membrane.

The separation by polyacrylamide gel electrophoresis and subsequent enzymatic analysis of the components of the guinea pig intestinal brush border membrane revealed the presence of three enzyme complexes: maltase-glucoamylase, maltase-sucrase-glucoamylase and maltase-sucrase. Additional bands possessing lactase, trehalase and alkaline phosphatase activity were identified but no phlorizin hydrolase or palatinase was detectable. After exposure to strong dissociating conditions the bands possessing enzymatic activity were either absent or greatly reduced in intensity.

Alkaline Phosphatase↗
PubMed1977

The brush border membrane in hereditary sucrase-isomaltase deficiency: abnormal protein pattern and presence of immunoreactive enzyme.

In a child with hereditary sucrase-isomaltase deficiency immunoreactive enzyme was present in the intact duodenal mucosa. Polyacrylamide gel electrophoresis carried out with membrane fragments of an intestinal biopsy showed an abnormal protein band without enzyme activity. The mucosa had a relatively high residual isomaltase activity which was recovered from the gel in a position suggesting higher than normal molecular weight. The results indicated that in this patient the primary structural defect was in the sucrase moiety which was enzymatically inactive. The isomaltase subunits may have aggregated into a large molecular weight complex because of unavailability of their partners. The observation also provided evidence for separate biosynthesis of the two moieties of the sucrase-isomaltase complex.

Cell Membrane↗
PubMed1977

Classification at time of diagnosis and subsequent survival in children with cystic fibrosis.

The survival rates in 204 patients suffering from cystic fibrosis observed between January 1956 and June 1976 were recorded. The patients were divided into five groups according to the symptoms present at the time of diagnosis and survival rates were recorded separately for each group. Survival was less good in the group of patients presenting initially with pulmonary symptoms compared to the group presenting with gastrointestinal symptoms. In the group presenting with meconium ileus survival was poor initially, but later in the course of the disease it became similar to that observed in the other groups. The differences in survival between the different categories occurred during the first two years after diagnosis. The study shows that, on clinical grounds, a severe form of the disease which is characterized by early manifestation of pulmonary symptoms and poor survival can be distinguished from a more protracted form with a better survival. Because of the great inter-individual variability large numbers of patients will have to be evaluated in order to achieve statistically significant results in studies which attempt to compare different therapeutic approaches. If such numbers cannot be reached, it may be necessary to compare only patients who belong to the same symptomatic category.

Child, Preschool↗
PubMed1976

Protein patterns of brush-border fragments in congenital lactose malabsorption and in specific hypolactasia of the adult.

Brush-border membrane proteins of the small-bowel mucosa were separated on polyacrylamide gels from intestinal biopsy specimens obtained from four children with congenital lactose malabsorption and from two adults with specific hypolactasia. In three patients with the congenital type of lactase deficiency the protein band corresponding to brush-border lactase was reduced in intensity, but was never completely absent. No difference in gel patterns was detected when this pattern in congenital deficiency was compared to that obtained from the two patients with adult-type selective hypolactasia. In one patient with congenital lactose malabsorption the protein band corresponding to lactase activity was not detectable. The findings suggest that the mechanisms leading to low lactase activity in the congenital and adult forms of lactose intolerance are similar.

Adult↗
PubMed1976

[The blood-xylose test in childhood: correlation between 1 hour blood-xylose levels and numbers of intraepithelial lymphocytes in intestinal mucosa in celiac disease].

In 59 children who underwent diagnostic small-intestinal biopsies the correlation between the intraepithelial lymphocyte infilration of the distal duodenal mucosa and the blood-xylose concentration 1 h after ingestion of 5 g D-xylose was investigated. 16 patients with active coeliac disease had blood-xylose values below 20 mg%, and the correlation between blood-xylose levels and the numbers of intraepithelial lymphocytes in this same group of patients was found to be highly significant. Provided that the methodology is meticulously followed, it is our experience that the one-hour blood-xylose test, in addition to the clinical investigation, facilitates the decision whether or not to perform a small-intestinal biopsy in the diagnosis and follow-up of coeliac disease in childhood. The test however cannot replace the intestinal biopsy which remains the only acceptable criterion for the diagnosis of this disease.

Adolescent↗
PubMed1975

Biliary lipid composition in early childhood.

The biliary lipid composition was studied in 11 children without hepatic or gastrointestinal disease who ranged in age from 15 to 54 months. The molar percentages of cholesterol, bile acids and phospholipids in the biliary lipid mixture averaged 5.0 +/- 1.1; 80 +/- 6.1 and 15 +/- 6.2%, respectively. Cholic, chenodeoxycholic, deoxycholic and ursodeoxycholic acid comprised 48; 45; 4 and 3% of total bile acids, respectively. A comparison of the lipid composition with data reported in the literature for the adult reveals that the molar percentage of cholesterol is relatively low in early childhood. This could be one of the factors which is responsible for the low incidence of cholesterol gallstones in this age group.

Adult↗
PubMed1975

Intestinal enterokinase deficiency. Occurrence in two sibs and age dependency of clinical expression.

Intestinal enterokinase deficiency in 2 sibs in described. A boy failed to gain weight and had vomiting, diarrhoea, oedema, hypoproteinaemia, and anaemia in early infancy. His duodenal juice contained very low or absent proteolytic enzyme activity, which increased markedly after addition of enterokinase. He was treated with pancreatic extract and gained weight rapidly. At 44 months of age he is normal, apart from some development delay, and no longer needs pancreatic extract. His older sister, who had had similar symptoms in early infancy but then grew normally, had the same abnormality in her duodenal juice when seen at 4 years of age. Enterokinase activity was virtually absent in the duodenal mucosa of both patients. Mucosal morphology was normal. The findings suggest that enterokinase deficiency is an inherited congenital defect and not the result of mucosal damage. Affected patients may show spontaneous improvement and normal growth after the age of 6 to 12 months. This phenomenon may be related to the decreasing growth volocity during the first 2 years of life and the concimitant decrease in protein requirements per unit bodyweight.

Amylases↗
PubMed1975

Secretin snuff: evaluation of the action on pentagastrin-stimulated gastric acid secretion and on pancreatic bicarbonate production.

In an informative qualitative study 75 U (near the range of 1 U/kg) secretin given as a snuff resulted in a weak but significant stimulation of pancreatic bicarbonate output in 8 volunteers studied. The result further indicated that this dose would slightly inhibit pentagastrin-stimulated gastric acid secretion. This was confirmed in a quantitative study at the dose of 150 U (similar to 2 U/kg), and the mean amount of inhibition of MAO was 30% in the 10 subjects studied. A supramaximal dose of 1 mg (approximatively 54 U/kg) of synthetic secretin given to one volunteer resulted in a transient block of near maximally pentagastrin-stimulated gastric acid secretion. The amount of acid inhibition as compared to a control experiment was 45% in the first and 52% in the two post-secretin hours. These results indicate that secretin given as a snuff at dose levels that would induce maximal pancreatic secretion when given as an i.v. injection results only in a weak inhibition of stimulated gastric acid secretion and evokes only a little stimulation of pancreatic bicarbonate secretion. Supramaximal secretin snuff doses have, however, a potent effect on both gastric and pancreatic secretion that is of similar order to that achieved by intravenous secretin. Owing to the obviously incomplete absorption of secretin through the nasal mucosa, secretin snuff is unlikely to solve the therapeutic problem of duodenal ulcer disease. If, however, an active fragment of the peptide could be synthetized at a reasonable price, the greater convenience of pernasal application might compensate for the partial loss of action.

Adult↗