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We studied the effect of intravenous lipid infusion on lipid peroxidation as measured by breath pentane. Pentane, plasma alpha-tocopherol (alpha-tox) and plasma gamma-tocopherol (gamma-toc), selenium, and Se-dependent glutathione peroxidase (Se-GSHPx) were measured in 10 normal control subjects and in 10 home parenteral nutrition (HPN) patients before and after infusion of 100 mL Nutralipid 10% over 30 min. Before infusion, breath pentane was significantly higher and alpha-toc was significantly lower in the HPN group than in the control subjects. These two measurements were significantly negatively correlated (r = -0.54, p less than 0.05). Pentane, alpha-toc, and Se-GSHPx were significantly increased in both groups after lipid was infused but were still significantly higher in HPN patients than in control subjects. Thus, infusion of a small amount of lipid rich in linoleic acid induced a significant increase in breath pentane, reflective of increased lipid peroxidation.

Because both vitamin E and selenium protect against lipid peroxidation, we evaluated the relationship between breath pentane, evolved from the peroxidation of linoleic acid, and plasma levels of alpha-tocopherol (vitamin E), Se, and Se-dependent glutathione peroxidase (Se-GSHPx). Nine home parenteral-nutrition (HPN) patients received added Se in intravenous solutions and were compared with 10 normal control subjects. The excretion of pentane (pmol.kg-1.min-1, means +/- SEM) in control subjects (6.34 +/- 0.96) was significantly lower than in HPN patients (15.02 +/- 1.12, p less than 0.001). alpha-Tocopherol (mumol/L), Se (mumol/L), and Se-GSHPx (U) values were, respectively, 18.13 +/- 1.70, 1.70 +/- 0.05, and 5.34 +/- 0.27 in control subjects and 10.21 +/- 1.66, 1.35 +/- 0.14, and 7.01 +/- 0.31 in HPN patients. All differences were statistically significant. Significant negative correlations were observed between plasma alpha-tocopherol levels and HPN duration and between pentane output and plasma alpha-tocopherol levels (r = -0.58, p less than 0.01). In HPN patients with reduced plasma alpha-tocopherol levels associated with increased pentane output, there is, inferentially, increased lipid peroxidation despite normal plasma Se and Se-GSHPx levels.

Increased awareness of non-classical presentations and more reliable screening tests have led to higher detection rates for coeliac disease in elderly adults. Clinical presentations are influenced largely by the long-standing course of the subclinical disease before diagnosis. In the majority of elderly patients, weight loss, diarrhoea and iron deficiency anaemia are present. With a delay in diagnosis, there are increased risks of associated autoimmune diseases, of neoplasms (mostly small bowel lymphoma) and of metabolic bone diseases. Thyroid disease is the most common autoimmune disease. Lymphoma may be the initial presentation or may complicate the clinical course of well established coeliac disease. Osteopenia is very common at presentation, can be clinically severe and require specific therapy in addition to the gluten-free diet. The high risk of complications in elderly patients with coeliac disease warrants a systematic approach in their investigation and management.

Pentane, which evolves from the reaction involving omega-6 fatty acids, is a good index of lipid peroxidation. We describe a method for measuring breath pentane excretion in adult humans. After a 4-minute washout period, expired air was analyzed by gas chromatography. Breath was passed through a cooled loop of alumina to adsorb, concentrate, and release, on heating, pentane. Pentane was analyzed by a Porasil-D column with a derived calibration curve. The mean excretion of pentane in 10 normal adults was 6.34 +/- 0.96 pmol X kg-1 X min-1 (mean +/- SEM) and was significantly higher in five patients with plasma vitamin E deficiency (15.39 +/- 1.84 pmol X kg-1 X min-1). There was a significant negative correlation between pentane output and plasma vitamin E levels (r = -0.66, p less than 0.01). Moreover, breath pentane excretion was significantly decreased after a 10-d supplementation with vitamin E in five normal subjects. We conclude that breath pentane output is a sensitive, noninvasive, functional test for assessing vitamin E status.

Only half of patients with IBD are aware of the risks of smoking associated with their disease, whereas their intent to quit smoking is directly related to their awareness. In the scope of IBD's treatment, management of smoking cessation should be undertaken in all smokers.

The aim of this work was to determine the influence of the vagus on the circulating levels of immunoreactive (IR) motilin. Five mongrel dogs were equipped with chronically implanted electrodes in the small intestine to record the myoelectrical activity. The release of IR motilin during fasting, after a meal, and during an infusion of insulin was studied before and after truncal vagotomy at the diaphragmatic level. When tested at least two weeks after the operation, the motility pattern of the small intestine and the secretion of IR motilin remained unaltered by vagal section. Cyclic increases in IR motilin associated with phase III's of the interdigestive myoelectric complexes were still observed after vagotomy (maximum levels of IR motilin: 250 +/- 37 versus 239 +/- 19 fmol X mL-1, not significant), and they were still abolished by feeding or by insulin. However, an inhibitory influence can probably be mediated by the vagus since, in normal animals, vagal stimulation by a "modified sham feeding" (tease feeding or presentation of food) at the beginning of a period of phase III activity promptly interrupted this part of the complex and decreased significantly the release of IR motilin by about 20%. The release of motilin is not chronically altered by distal vagotomy in dogs.