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T A Robb

Publications and source records attributed to T A Robb.

26 records · Page 2Linked to original sources
PubMed1983

Detection of primary and secondary sucrose malabsorption in children by means of the breath hydrogen technique.

Eighty-one breath hydrogen tests were performed in 72 children who were investigated either because of chronic diarrhoea or recurrent abdominal pain, or because they were relatives of patients with congenital sucrase-isomaltase deficiency. The results of tests on 16 patients were positive (sucrase-isomaltase deficiency, seven patients; secondary sucrose malabsorption, nine patients). Hydrogen production was higher in patients with sucrase-isomaltase deficiency (mean, 96 ppm; range, 20 ppm to 432ppm) than in those with secondary sucrose malabsorption (mean, 21 ppm; range, 12ppm to 51ppm). All patients with positive test results responded to sucrose restriction, and those with secondary malabsorption subsequently became well. The breath hydrogen test is a sensitive, non-invasive method for detecting sucrose malabsorption, whether due to a primary deficiency or secondary to other bowel disorders. Guidelines for improving the accuracy and reproducibility of the breath hydrogen test are discussed.

Breath Tests↗
PubMed1983

Reproducibility of expired breath hydrogen levels in the neonate: a comparison of two methods for sample collection.

We have compared a nasopharyngeal catheter method for breath sampling and a valved collection device. Sample quality was assessed by simultaneous oxygen measurement and reproducibility was checked by the analysis of 50 pairs of samples from four premature neonates. Both collection methods produced samples of highly variable quality suggesting a variable mixture of alveolar and non-alveolar air as well as differences in expired oxygen levels between babies. The mean oxygen levels were similar for both sampling techniques. Linear regression analysis of paired hydrogen results showed a highly significant correlation coefficient r = 0.73. This was improved markedly to r = 0.94 by normalization of hydrogen values based on observed oxygen levels, and so supports the earlier article by Robb and Davidson [1]. All breath hydrogen analyses require a measure of sample quality. Reproducible results and meaningful changes in hydrogen concentration in breath samples can only be achieved by correction according to sample quality. Correction to a common oxygen value should allow quantitative comparisons between patients. Samples were best collected from neonates by the nasopharyngeal catheter method, which least disturbed the patient, allowed multiple sample collection and gave lower oxygen and higher hydrogen values where large differences between pairs occurred.

Autoanalysis↗
PubMedDate not supplied

Recovery of the small intestine in coeliac disease on a gluten-free diet: changes in intestinal permeability, small bowel morphology and T-cell activity.

Intestinal permeability was assessed before and 1, 2, 4, 8 and 12 weeks after commencing a gluten-free diet (GFD) in eight coeliac subjects. Intestinal morphology was quantified in six coeliac subjects on a normal diet, six coeliac subjects on a GFD, and 21 normal subjects. T-cell activity was measured in the eight coeliac subjects by soluble interleukin-2 receptor (sIL-2R) concentration (normal less than 477 U/mL). Intestinal permeability was increased 10-fold with a geometric mean value of 0.72 on a normal diet, and decreased to 0.17 at 4 weeks (P = 0.04), to 0.07 at 8 weeks (P = 0.010), and to 0.20 at 12 weeks (P = 0.015) of a GFD. Two of the eight subjects showed a poor response to gluten withdrawal. Quantitative intestinal morphology showed no significant improvement after 3 to 6 months of a GFD. Mean +/- s.d. sIL-2R concentrations in the eight subjects were increased 5-fold higher than control values at 1400 +/- 530 U/mL on a normal diet and decreased to 750 +/- 200 U/mL after 12 weeks of a GFD (P = 0.004). We conclude that intestinal permeability improves rapidly in the majority of coeliac subjects after commencing a GFD, although some abnormal permeability and increased T-cell activity persists. This may be due to varying degrees of gluten ingestion resulting in continued immune activation.

Adult↗