PubMed Health⌕ Search

Biomedical subjects

G Neale

Publications and source records attributed to G Neale.

At least 55 records · Page 3Linked to original sources
PubMed1981

Bile acid inhibition of vitamin B12 binding by intrinsic factor in vitro.

The effect of conjugated and unconjugated bile acids on the binding of vitamin B12 to intrinsic factor was investigated. The dihydroxy bile acids (deoxycholic, glycodeoxycholic, taurodeoxycholic, glycochenodeoxycholic, and taurochenodeoxycholic) inhibit the binding of intrinsic factor to vitamin B12 at physiological concentrations. On the other hand, the trihydroxy bile acids (cholic, glycocholic, and taurocholic) are not effective in this respect. The inhibition is dependent both on concentration and time, and its pattern is similar to that previously reported for duodenal juice. On column chromatography, there is a close correlation between the degree in intrinsic factor inhibition and the total acid concentration in the duodenal juice. The binding of vitamin B12 by R protein in saliva is not affected by bile acids. The results show that bile acids at concentrations found in duodenal juice inhibit intrinsic factor vitamin B12 binding. It is suggested that this observation may have physiological significance for vitamin B12 absorption.

Bile Acids and Salts↗
PubMed1980

Effect of bile on vitamin B12 absorption.

The standard double-isotope Schilling test was used to study vitamin B12 absorption in seven patients with obstructive jaundice and 10 with T-tube bile duct drainage after cholecystectomy and bile duct exploration. In three and five of these patients respectively absorption was impaired. In the second group six patients were restudied after removal of the T tube, and in each case absorption was improved. Similar results were obtained after bile duct ligation in rats. Bile exclusion produced a 50-60% reduction in renal and hepatic uptake of vitamin B12 from the intestinal lumen. The malabsorption was corrected by replacing bile. These studies suggest that bile plays a part in the normal absorption of vitamin B12.

Adult↗
PubMed1978

Diagnosis and management of obscure gastrointestinal bleeding.

Twelve consecutive patients presenting with unexplained recurrent gastrointestinal bleeding were investigated by selective visceral angiography. A cause for the bleeding was shown in all 12 cases, and in eight the lesion responsible was diagnosed radiologically as an area of angiodysplasia. Abnormal areas were pinpointed by fluoroscopy and examination of the resected bowel with a dissecting microscope after injecting the vessels with barium. Histologically these areas had various microvascular abnormalities. Angiodysplasia is a useful descriptive radiological term, but does not seem to represent a single pathological entity.

Adult↗
PubMed1978

Serum and faecal lysozyme in inflammatory bowel disease.

Lysozyme (EC 3.2.1.17) concentrations were measured in the serum and stools of patients with inflammatory bowel disease and compared with the concentrations in similar material from normal controls, patints with non-inflammatory gastrointestinal disease, and patients without gastrointestinal disease. By the turbidometric method, values of lysozyme (microgram/ml +/- SD) are considerably greater in the serum of patients with active Crohn's disease (9.2 +/- 2.7) than in the serum of healthy controls (4.4 +/- 2.0). They do not, however, distinguish individual patients with Crohn's disease from those with ulcerative colitis nor from those with a variety of other gastrointestinal conditions. The lysoplate method gives much higher values for serum lysozyme than the turbidometric method but there is a considerable overlap between the results for patients with Crohn's disease (60.1 +/- 30.7) and normal controls (27.4 +/- 17.5). There is only a moderate correlation between the results given by the two methods (r = 0.56) and it is suggested that factors other than enzyme activity and methodological variation are responsible for the observed differences. This is supported by the finding that, with Crohn's disease in remission, serum lysozyme values (lysoplate) return to normal values but with the turbidometric method remain raised. Mean faecal lysozyme levels, expressed either as a concentration or as total daily excretion, in patients with inflammatory bowel disease are very significantly greater than values in healthy controls and in diseased subjects without diarrhoea but are not significantly different from those subjects with other causes of diarrhoea.

Colitis, Ulcerative↗
PubMed1977

Lysosomal changes in liver tissue from patients with the Dubin-Johnson-Sprinz syndrome.

1. Clinical, morphological and biochemical data, including data obtained from the application of subcellular fractionation techniques to liver biopsy specimens, are presented for two patients with the Dubin-Johnson-Sprinz (DJS) syndrome. 2. Subcellular fractionation experiments demonstrate that the lysosomes, which have strikingly reduced equilibrium densities, accumulate melanin. Morphological studies confirm the presence of pigments within lysosomes. 3. Although there are increased activities of lysosomal acid hydrolases in the liver tissue from patients with the DJS syndrome, the integrity of these organelles is essentially normal and therefore the accumulation of pigment would not be expected to initiate liver damage. The DJS syndrome is thus a benign type of secondary lysosomal storage disease.

Adult↗
PubMed1976

Functional and biochemical evidence of damage to enterocytes induced by triparanol: role of lysosomes and the effect of gluten-free diet.

1. Functional and biochemical studies were performed on the small intestine of control rats, and the results were compared with similar studies on animals given triparanol at a dosage of 0.114 mmol/kg daily for 10 days. The animals given triparanol were fed with either standard rat food or a gluten-free diet. 2. By using a recirculating-perfusion technique in vivo, it was shown that absorption of galactose from an 8 mmol/l solution was impaired in the ileum but not in the jejunum of the triparanol-treated rats. 3. Assays of marker enzymes for the principal subcellular organelles were performed on isolated jejunal and ileal enterocytes. In the ileum there was a striking decrease in lysosomal enzyme activities and a smaller but significant decrease of lactate dehydrogenase, catalase and malate dehydrogenase activities. In the jejunum there was no significant change in the activities of these enzymes. 4. Measurements of lysosomal integrity indicated that ileal lysosomal fragility was markedly increased and that jejunal lysosomes were affected to a much smaller extent. 5. These effects of triparanol could not be ameliorated by feeding with a gluten-free diet.

Acetylglucosaminidase↗
PubMed1976

A familial abnormality of circulating vitamin B12 binding proteins: occurrence in a family of high serum concentrations of transcobalamin II.

A family is described in which two members (a father and a daughter), both with quiescent ulcerative colitis, had abnormally high serum concentrations of a vitamin B12 binding protein. This protein had the molecular weight of transcobalamin II on gel filtration, and behaved like transcobalamin II with respect to its elution from DE-23 cellulose, its inhibition at acid pH, its absorption by uncoated charcoal, its binding by anti-TC II antibodies, and its ability to transfer vitamin B12 to transformed lymphocytes. Its plasma clearance and tissue distribution when injected into rabbits was indistinguishable from that of transcobalamin II from normal subjects. It migrated on electrophoresis in the beta, gamma region. This is the first case report of related subjects in whom high serum concentrations of transcobalamin II have been observed.

Blood Proteins↗
PubMed1976

Studies of tryptophan and albumin metabolism in a patient with carcinoid syndrome, pellagra, and hypoproteinemia.

Detailed studies of protein metabolism were undertaken in a patient with pellagra and hypoproteinemia associated with the carcinoid syndrome both before and after treatment. The synthesis of albumin improved from 82 mg per kg per day to 135 mg per kg per day with little change in the daily excretion of 5-hydroxyindole acetic acid. After treatment with nicotinamide the patient made good progress with a complete resolution of the signs of pellagra and protein malnutrition. These results support the hypothesis that a reduced availability of the essential amino acid L-tryptophan may limit the synthesis of albumin and nicotinic acid in patients with the carcinoid syndrome who become anoretic.

Adult↗