Structural and functional correlations in the atrophic mucosa of self-emptying blind loops of rat jejunum

Abstract. Marked atrophy of the mucosa develops in self-emptying blind loops of rat jejunum. The application of microdissection techniques revealed a 74% reduction in the mucosal surface area of the blind loops, 3 weeks after their creation.
Kinetic studies of the influx of L-phenylalanine and β-methyI-D-glucoside into rings of blind loops showed that the K _m for both mechanisms was unchanged, but that there was a small reduction in the K_max, for both substrates, when expressed in terms of unit weight of incubated tissue; this attained 31% for phenylalanine and 12% for β-methyl-glucoside.
When the kinetic data were combined with the mor-phometric results, it could be shown that the V _max for both substrates, when expressed per unit area of mucosal surface, was more than twice as large in the blind loop epithelium as in normal tissue. Such findings indicate either that the individual cells of the blind loop epithelium possess more transport sites than normal. or that there is a greater proportion of absorptive cells within the blind loop mucosa.     

A STUDY OF BETA-CELL FUNCTION AFTER GLUCAGON STIMULATION IN THALASSAEMIA MAJOR TREATED BY HIGH TRANSFUSION PROGRAMME

An increased incidence of diabetes mellitus and glucose intolerance has been reported in thalassaemia major treated with a high transfusion programme (HTP). To investigate beta-cell function, serum immunoreactive insulin (IRI), C-peptide (CP) and glucose were measured fasting and at 3, 6 and 10 min after i.v. administration of 1 mg glucagon in 20 thalassaemia patients treated by many transfusions and in nine healthy control subjects. Fasting C-peptide concentrations (mean +/- SEM) were higher in the thalassaemic group (2.15 +/- 0.17 ng/ml) than in the controls (1.41 +/- 0.13 ng/ml). After stimulation with glucagon, C-peptide concentrations were consistently higher (P less than 0.01) by approximately 50% in the thalassaemic than in the control group (5.29 +/- 0.31 vs 3.36 +/- 0.21 ng/ml, at 3 min; 5.22 +/- 0.30 vs 3.53 +/- 0.21 ng/ml at 6 min and 4.69 +/- 0.27 vs 3.30 +/- 0.17 ng/ml after 10 min). Plasma IRI concentrations increased in both groups after glucagon stimulation but were not significantly different. The glucose values were approximately 15% higher at each sampling time in the thalassaemic group than those of the normal subjects. It is concluded that disturbances in carbohydrate metabolism in thalassaemia major treated with HTP are the consequence of hepatic cirrhosis which accompanies secondary haemosiderosis, and possibly iron deposition in the beta-cells of the pancreas.     

IgE to food allergens are highly prevalent in patients allergic to pollens, with and without symptoms of food allergy

Serum samples from 274 patients allergic to one or more of three pollens (birch, grass, mugwort), from 36 patients allergic to cat and/or Dermatophagoides pteronyssinus but not to pollen and from 55 non-allergic controls, as well as 20 cord blood samples, were examined for specific IgE to six ‘pollen-associated’ food allergens In uiing a new sensitive assay (CAP). A questionnaire asking for reactions to food was also sent to all patients. In the pollen group, 111 patients (47%) were positive (≥0.71 kU/l) fora food allergen (392 positive tests). Of these, 92 were sensitive to apple, 68 to potato, 64 to carrot, 63 to celery, 61 to peach and 44 to melon. In the non-allergic group, no IgE to any of the food allergens tested was found, whereas in the group allergic to non-pollen allergens, only one individual had such an IgE. The CAP assay was found to he more sensitive than RAST for the allergens studied. A history of clinical reactions (oral symptoms in 67, rhinoconjunctivitis in 65, asthma in 42 and urticaria in 39) to the corresponding food allergen was reported mainly by patients with positive CAP. In conclusion, we found a high prevalence of IgE to some food allergens in patients allergic to pollen and Ihe absence of such antibodies in the control groups. The new in vitro assay, being moresensitue than previous ones, indicated a high prevalence of food specific IgE in pollen allergic patients, which in many cases did not correspond to clinical symptoms of food allergy.