Symptomatic suspected gluten exposure is common among patients with coeliac disease on a gluten-free diet.

BACKGROUND: A gluten-free diet is the only recommended treatment for coeliac disease. AIM: To determine the prevalence and characteristics of reactions to gluten among persons with coeliac disease on a gluten-free diet. METHODS: Adults with biopsy proven, newly diagnosed coeliac disease were prospectively enrolled. A survey related to diet adherence and reactions to gluten was completed at study entry and 6 months. The Coeliac Symptom Index, Coeliac Diet Assessment Tool (CDAT) and Gluten-Free Eating Assessment Tool (GF-EAT) were used to measure coeliac disease symptoms and gluten-free diet adherence. RESULTS: Of the 105 participants, 91% reported gluten exposure <1 per month and median CDAT score was 9 (IQR 8-11), consistent with adequate adherence. A suspected symptomatic reaction to gluten was reported by 66%. Gluten consumption was unsuspected until a reaction occurred (63%) or resulted from problems ordering in a restaurant (29%). The amount of gluten consumed ranged from cross-contact (30%) to a major ingredient (10%). Median time to symptom onset was 1 h (range 10 min to 48 h), and median symptom duration was 24 h (range 1 h to 8 days). Common symptoms included abdominal pain (80%), diarrhoea (52%), fatigue (33%), headache (30%) and irritability (29%). CONCLUSIONS: Reactions to suspected gluten exposure are common among patients with coeliac disease on a gluten-free diet. Eating at restaurants and other peoples' homes remain a risk for unintentional gluten exposure. When following individuals with coeliac disease, clinicians should include questions regarding reactions to gluten as part of their assessment of gluten-free diet adherence.

Living gluten-free: adherence, knowledge, lifestyle adaptations and feelings towards a gluten-free diet.

BACKGROUND: A gluten-free diet (GFD) requires tremendous dedication, involving substantive changes to diet and lifestyle that may have a significant impact upon quality of life. The present study aimed io assess dietary adherence, knowledge of a GFD, and the emotional and lifestyle impact of a GFD. METHODS: Community dwelling adults following a GFD completed a questionnaire with items related to reasons for avoiding gluten, diagnostic testing, GFD adherence, knowledge and sources of information about a GFD, the Work and Social Adjustment Scale, and the effect of a GFD diet on lifestyle, feelings and behaviours. RESULTS: Strict GFD adherence among the 222 coeliac disease (CD) patients was 56%. Non-CD individuals (n = 38) were more likely to intentionally ingest gluten (odds ratio = 3.7; 95% confidence interval = 1.4-9.4). The adverse impact of a GFD was modest but most pronounced in the social domain. Eating shifted from the public to the domestic sphere and there were feelings of social isolation. Affective responses reflected resilience because acceptance and relief were experienced more commonly than anxiety or anger. Non-CD respondents were less knowledgeable and less likely to consult health professionals. They experienced less anger and depression and greater pleasure in eating than CD respondents. CONCLUSIONS: The findings obtained in the present suggest there is good potential for positive adaptation to the demands of a GFD; nevertheless, there is a measurable degree of social impairment that merits further study. The GFD may be a viable treatment option for conditions other than CD; however, education strategies regarding the need for diagnostic testing to exclude CD are required.

An inhibitor of poly (ADP-ribose) synthetase activity reduces contractile dysfunction and preserves high energy phosphate levels during reperfusion of the ischaemic rat heart.

The cardioprotective properties of inhibition of poly (ADP-ribose) synthetase (PARS) were investigated in the isolated perfused heart of the rat. Hearts were perfused in the Langendorff mode and subjected to 23 min total global ischaemia and reperfused for 60 min. Left ventricular function was assessed by means of an intra-ventricular balloon. High energy phosphates were measured by 31P-NMR spectroscopy. Intracellular levels of NAD were measured by capillary electrophoresis of perchloric acid extracts of hearts at the end of reperfusion. Reperfusion in the presence of the PARS inhibitor 1,5 didroxyisoquinoline (ISO, 100 microM) attenuated the mechanical dysfunction observed following 1 h of reperfusion; 27+/-13 and 65+/-8% recovery of preischaemic rate pressure product for control and 100 microM ISO, respectively. This cardioprotection was accompanied by a preservation of intracellular high-energy phosphates during reperfusion; 38+/-2 vs 58+/-4% (P<0.05) of preischaemic levels of phosphocreatine (PCr) for control and 100 microM ISO respectively and 23+/-1 vs 31+/-3% (P < 0.05) of preischaemic levels of ATP for control and 100 microM ISO respectively. Cellular levels of NAD were higher in ISO treated hearts at the end of reperfusion; 2.56+/-0.45 vs 4.76+/-1.12 micromoles g(-1) dry weight (P<0.05) for control and ISO treated. These results demonstrate that the cardioprotection afforded by inhibition of PARS activity with ISO is accompanied by a preservation of high-energy phosphates and cellular NAD levels and suggest that the mechanism responsible for this cardioprotection may involve prevention of intracellular ATP depletion.

Photodynamically generated bovine serum albumin radicals: evidence for damage transfer and oxidation at cysteine and tryptophan residues.

Porphyrin-sensitized photoxidation of bovine serum albumin (BSA) results in oxidation of the protein at (at least) two different, specific sites: the Cys-34 residue giving rise to a thiyl radical (RS.); and one or both of the tryptophan residues (Trp-134 and Trp-214) resulting in the formation of tertiary carbon-centred radicals and disruption of the tryptophan ring system. In the case of porphyrins such as hematoporphyrin, which bind at specific sites on BSA, these species appear to arise via long-range transfer of damage within the protein structure, as the binding site is some distance from the ultimate site of radical formation. This transfer of damage is shown to depend on a number of factors including the conformation of the protein, the presence of blocking groups and pH. Alteration of the protein conformation results in radical formation at additional (or alternative) sites, as does blocking of the preferred loci of radical formation. The formation of these thiyl and tryptophan-derived radicals does not lead to significant aggregation or fragmentation of the protein, though it does result in a dramatic enhancement in the susceptibility of the oxidised protein to proteolytic degradation by a range of proteases. The generation of protein-derived radicals also results in an enhancement of photobleaching of the porphyrin, suggesting that protein radical generation is linked to porphyrin photooxidation.

Protein hydroperoxides and carbonyl groups generated by porphyrin-induced photo-oxidation of bovine serum albumin.

Porphyrin-sensitized photo-oxidation of bovine serum albumin results in oxidation at specific sites to produce protein radical species: at the Cys-34 residue (to give a thiyl radical) and at one or both tryptophan residues (Trp-134 and Trp-214) to give tertiary carbon-centered radicals and cause disruption of the indole ring system. This study shows that these photo-oxidation processes also consume oxygen and give rise to hydrogen peroxide, protein hydroperoxides, and carbonyl functions. The yield of hydrogen peroxide, protein hydroperoxides, and carbonyl functions is shown to be dependent on illumination time, the nature of the sensitizer, and the concentration of oxygen; the yield of hydroperoxides can also be markedly diminished by the presence of a spin trap which reacts with the initial protein radicals. The mechanism of formation of the protein hydroperoxides is suggested to be primarily through type I processes (i.e., independent of singlet oxygen), while type II (singlet oxygen) mechanisms may play a significant role in protein carbonyl formation. Reaction of the protein hydroperoxide species with metal ion complexes is shown to produce further protein-derived radicals which are predominantly present on amino acid side chains.

Use of isotopically labelled spin-traps to determine definitively the presence or absence of non-radical addition artefacts in EPR spin-trapping systems.

EPR spin-trapping, although a powerful, sensitive technique for the study of free radicals, can be susceptible to artefacts; one of the most intractable to determine has been the non-radical addition of a substrate to a spin-trap followed by oxidation of the product to an EPR-detectable nitroxide. This work details how differentially isotopically labelled spin-traps (either nitroso or nitrone) may be used to determine the presence (or absence) of such artefacts, and provide a semi-quantitative measure of the extent of their contribution to the total EPR spectra in spin-trapping reactions. Artefactual 'ene' addition of the nitroso spin-trap 3,5-dibromo-4-nitroso-benzenesulphonic acid (DBNBS) to tryptophan followed by oxidation to EPR-detectable products has been confirmed, as has its nucleophilic addition to the thiol of glutathione to give non-EPR detectable products. The nitrone α-phenyl-N-tert-butylnitrone (PBN) exhibited no such reactivity.

A study of photochemically-generated protein radical spin adducts on bovine serum albumin: the detection of genuine spin-trapping and artefactual, non-radical addition in the same molecule.

Photo-oxidation of bovine serum albumin (BSA) by porphyrins produces protein-centred radicals that can be spin trapped by 3, 5-dibromo-4-nitrosobenzenesulphonic acid (DBNBS) and 5, 5-dimethyl-1-pyrroline-N-oxide (DMPO). In the case of DMPO, a thiyl radical from the Cys-34 residue is trapped, whereas with DBNBS signals from both this thiyl and tertiary carbon-centred species are observed. However, specific chemical modification of the Cys-34 residue, in combination with dual-isotope spin-trapping techniques, shows that the signal assigned to the Cys-34 thiyl adduct with DBNBS is a nitroxide artefact resulting from sequential (non-radical) nucleophilic addition and oxidation. In contrast, both the Cys-34 thiyl DMPO adduct and the tertiary carbon-centred DBNBS adducts result from genuine spintrapping. This study shows that such artefacts can be detected-even with anisotropic EPR spectra-through the use of appropriately substituted spin-traps, and that nitroso spin-traps need to be employed with great care in systems containing free thiol groups.

Alternative types of duodenal ulcer induced in mice by partial X irradiation of the thorax.

The present study extends our earlier observations [A. Michalowski, Br. J. Radiol. 54, 713 (1981); A. Michalowski and J. Burgin, in Progress in Radio-Oncology II, pp. 105-110] on gastrointestinal pathology in thorax-irradiated female CFLP mice. It shows that exposure of the lower mediastinum to single doses of 14-30 Gy X rays results in the formation of the proximal duodenal ulcer accompanied frequently by erosion of the antral gastric mucosa. X irradiation of the lateral thoracic fields is responsible for single ulcers in the proximity of duodenal papilla, often associated with a circumscribed area of degeneration of the fundic mucosa of the stomach. In view of the small amount of radiation received by the subdiaphragmatic parts of the alimentary tract, these gastro-duodenal lesions represent abscopal effects of thoracic irradiation.