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PubMed1998

Coeliac disease in children and adolescents with IDDM: clinical characteristics and response to gluten-free diet.

A total of 167 children and adolescents with insulin-dependent (Type 1) diabetes mellitus (97 males; age range 1.9-22.4 yrs) in a UK paediatric diabetic clinic were screened for coeliac disease using the IgA endomysial (EMA) test, or, in IgA deficient subjects, the IgG antigliadin (AGA) test. Antibody positive subjects were selected for small bowel biopsy, and confirmed coeliac cases started on a gluten free diet. Clinical features, height (Ht) standard deviation score (SDS), body mass index (BMI) SDS, HbA1c, insulin requirements' haemoglobin (Hb), mean red cell volume (MCV), serum folate and ferritin levels were evaluated at diagnosis and thereafter at 3-6 month intervals. A total of 156 subjects (93.4%) were antibody negative. Eleven (6.6%) were antibody positive (10 EMA/1 AGA; 6 males), of whom 9 had biopsies: 1 normal: 8 coeliac (4.8%; 5 males; 1 'classical'; 1 anaemia; 3 'atypical'; 3 asymptomatic). Seven coeliac subjects were followed during 12-24 months of dietary therapy. Pretreatment mean (range) Ht SDS = 0.08 (-1.66 to 1.88); BMI SDS = 0.32 (-0.82 to 1.29); HbA1c = 8.9 (6.2 to 11.3%); insulin dose = 0.98 (0.51 to 1.29) U kg(-1) day(-1). During treatment antibody status reverted to and remained negative, and symptoms resolved. By 24 months, there was a trend towards increased BMI SDS (mean (range) 1.31 (0.47 to 2.29), p = 0.248) and to reductions in HbA1c (8.1 (6.4-10.8), p = 0.697). Repeat small bowel biopsies were normal in 6 subjects (1 refused). No statistically significant changes occurred in any other parameters. In conclusion, serological screening is effective, although the therapeutic benefit of dietary therapy in asymptomatic cases remains uncertain.

Adolescent↗
PubMed2000

Qualitative and quantitative analysis of wheat gluten proteins by liquid chromatography and electrospray mass spectrometry.

Based on analysis by liquid chromatography/electrospray ionisation mass spectrometry, we have developed a new method for fast and sensitive fingerprinting of gliadins and glutenins in wheat flour. Using this procedure the two protein fractions from seven durum wheat varieties have been analysed by high resolution high performance liquid chromatographic separation coupled to accurate determination of molecular mass. In this way, the molecular mass of the single components from both gliadin and glutenin fractions were measured and more than forty components were detected for each fraction indicating a high heterogeneity. Although the chromatographic profiles were similar, the molecular masses of protein components with similar retention times among the varieties were often different. The difference ranged from a few mass units corresponding to single amino acid substitution(s) up to thousands implying peptide deletion or insertion along the protein chain. Two components representing about a half of the gliadin fraction, e.g. gamma(2)- and gamma(3)-gliadin, were identified through the N-terminal sequence and molecular mass determination. We suggest the use of the high level and the molecular mass of these gliadin components as markers to detect traces of wheat in gluten-free food preparations for celiac patients.

Amino Acid Sequence↗
PubMed2001

Effects of processing on biochemical and rheological properties of wheat gluten proteins.

Protein solubility increases during mixing at water absorption suitable for bread doughs. The changes that result from heat treatment may be much greater than the differences normally found among wheat varieties. Sheeting brings about a reduction in the gluten content and increase in gel protein content of doughs. This may be due to increase in temperature during sheeting as a result of work input to the dough resulting in protein denaturation. Drying at higher temperatures causes denaturation of pasta dough protein. In addition, it has been shown that high temperatures contribute to the formation of the protein network. During extrusion processing proteins are denatured and chemical bonds are weakened as result of heat and shear through the extruder.

Cooking↗
PubMed1997

Electrophoretic characterisation of fractions collected from gluten protein extracts subjected to size-exclusion high-performance liquid chromatography.

The electrophoretic analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE; reduced and unreduced) of fractions, collected from a size exclusion-high performance liquid chromatography (SE-HPLC) separation of gluten proteins using a column with pore size of around 400A, showed clear resolution for the seven elution ranges studied in two Australian bread wheat lines. Polymeric proteins - high molecular weight (HMW) glutenin subunits, low molecular weight (LMW) glutenin subunits, HMW albumins and some modified omega-gliadins - appeared exclusively in the region within the first peak of the chromatogram (fractions 1 to 5), the limit being a region that resolved as a small peak before the large peak of gliadins and where some omega-gliadins eluted. A larger proportion of HMW glutenin subunits and B subunits contributed to polymer formation of higher molecular weight. The polymer size decreased as the proportion of the other protein components increased.

Chemical Fractionation↗
PubMed2006

Development of a capillary electrophoresis method for the determination of soybean proteins in soybean-rice gluten-free dietary products.

CE has been applied for the first time to the simultaneous separation of soybean and rice proteins. Treated and untreated capillaries with different effective lengths as well as separation media at different pHs were tested. For that purpose, samples and standard solutions were prepared in 25:75 ACN-water media containing 0.3% v/v acetic acid. The use of an untreated capillary of 50 cm effective length together with an 80 mM borate buffer (pH 8.5) modified with 20% v/v ACN and UV detection at 254 nm were the conditions working the best. These conditions enabled the determination of soybean proteins in gluten-free dietary commercial products elaborated with soybean protein and/or soybean flour and rice flour using the standard additions calibration method. The method was linear up to 26 mg/mL of soybean proteins, the precision (expressed as RSD) was always better than 6%, and recoveries obtained for soybean proteins when spiking commercial products were very close to 100%.

Acetonitriles↗
PubMed1985

[Comparative studies on the enzymatic absorption of protein hydrolysates in the small intestines of the rat. 3. The absorption of trypsin, thermitatic and trypsin thermitatic wheat gluten hydrolysates in comparison with equimolar mixtures of free amino acids].

Tryptic, thermitatic, and tryptic-thermitatic wheat-gluten hydrolyzates as well as their equimolar amino-acid mixture were perfused through proximal and distal parts of the intestine (10 cm length) of non-narcotized rats. The total amino-acid concentration of the perfused solution was 50 mM. The tryptic hydrolyzate showed a significantly lower absorption of nitrogen and total amino acids than the amino-acid mixture. Both the supplied forms were very different as to their absorption pattern of the amino acids. The high variability of the percental absorption of the individual amino acids of the tryptic hydrolyzate results in a high coefficient of variation. The absorption of nitrogen and total amino acids from thermitatic and tryptic-thermitatic hydrolyzates is equal to that from the amino-acid mixture. In a peptidic form glutamic acid is more rapidly absorbed from the two hydrolyzates, and methionine from the tryptic-thermitatic hydrolyzate in both the intestinal parts. As to alanine and glycine this concerns only the distal intestinal part for both the hydrolyzates. There are no differences between the absorption patterns of the two hydrolyzates but in comparison with the amino-acid mixture and the tryptic hydrolyzate differences were evident. The coefficients of variation of both the hydrolyzates are significantly lower as compared to those of the tryptic hydrolyzate and the amino-acid mixture. All forms of supply are more rapidly absorbed in the distal than in the proximal part of the intestine.

Amino Acids↗
PubMed1990

Polyproline, beta-turn helices. Novel secondary structures proposed for the tandem repeats within rhodopsin, synaptophysin, synexin, gliadin, RNA polymerase II, hordein, and gluten.

Seven proteins each contain 8 to 52 tandem repeats of a unique class of oligopeptide. The consensus peptide for each is rhodopsin Tyr Pro Pro Gln Gly synaptophysin Tyr Gly Pro Gln Gly synexin Tyr Pro Pro Pro Pro Gly gliadin Tyr Pro Pro Pro Gln Pro RNA polymerase II Tyr Ser Pro Thr Ser Pro Ser hordein Phe Pro Gln Gln Pro Gln Gln Pro gluten Tyr Pro Thr Ser Pro Gln Gln Gly Tyr Although there is obvious variation of sequence and of length, the penta- to nonapeptides share an initial Tyr (or Phe) and have high Pro contents and abundant Gly, Gln, and Ser. We have evaluated helical models that both recognize the uniqueness of these sequence repeats and accommodate variations on the basic theme. We have developed a group of related helical models for these proteins with about three oligopeptide repeats per turn of 10-20 A. These models share several common features: Most of the phi dihedral angles are -54 degrees, to accommodate Pro at all positions except the first (Tyr). Except for the beta-turns, most psi dihedral angles are near +140 degrees as found in polyproline. Each oligopeptide has at least one beta-turn; several have two. Some contain a cis-Tyr, Pro peptide bond; a few have a cis-bond plus one beta-turn. Tyr side chains vary from totally exposed to buried within the helices and could move to accommodate either external hydrophobic interactions or phosphorylation. The several related structures seem to be readily interconverted without major change in the overall helical parameters, and therein may lie the key to their functions.

Amino Acid Sequence↗
PubMed1991

Disulphide bonds in wheat gluten: isolation of a cystine peptide from glutenin.

Gluten from the wheat variety Rektor was extracted with 70% aqueous ethanol. The residual protein (glutenin) was hydrolysed with trypsin. The partial hydrolysate was separated into seven fractions by gel permeation chromatography on Sephadex G 25. Four cystine-containing peptides were isolated from fraction 5 by reversed-phase high-performance liquid chromatography on ODS-Hypersil. The cystine peptides were detected by differential chromatography of the non-reduced and the reduced samples. The primary structure of the peptides was solved by the Edman degradation reaction and by partial hydrolysis with thermolysin. Three peptides derive from the alpha 2- and beta-purothionins. The structure of the fourth peptide was determined as (Formula; see text) This sequence corresponds to positions 44-48 of known sequences of the high molecular weight (HMW) subunits 9, 10, and 12. Since Rektor contains the HMW subunits 9 and 10, it could be concluded that two HMW subunits 9 or 10, or one subunit 9 and one subunit 10 were linked parallel via two disulphide bridges.

Amino Acid Sequence↗
PubMed1980

Complement studies in children with treated coeliac disease after gluten challenge.

Changes of the complement components in the sera of 13 children with treated coeliac disease were studied after gluten challenge. The levels of C 1 and C3-activator (factor B) were significantly decreased at 4 h after the challenge, as were the levels of total complement (CH 50) and the components C 1, C 4 and C 1-inactivator at 8 h. After 24 h most values returned to normal but there was another significant decrease in serum C 4 after 24 h, and for CH 50, C 1, C 2 and C 4 after 48 h.

Celiac Disease↗
PubMed2006

Effect of gluten-free diet on microbes in the colon.

The effect of gluten-free diet (GFD) and chitosan was evaluated in healthy individuals; GFD remarkably influenced the structure of the gut bacterial population and its metabolism. Administration of GFD and chitosan (3 g daily) significantly changed composition and metabolism of the bacterial population. Chitosan stimulated the counts of fecal chitinolytic bacteria and decreased the body mass of treated persons.

Adult↗
PubMed2006

Growth hormone impaired secretion and antipituitary antibodies in patients with coeliac disease and poor catch-up growth after a long gluten-free diet period: a causal association?

INTRODUCTION: Coeliac disease (CD) is usually associated with impaired growth in children. A gluten-free diet (GFD) induces a catch-up growth with the recovery of height in about 2 years. AIM AND DISCUSSION: The lack of the height improvement has been related to growth hormone (GH) secretion impairment. CD is an autoimmune disease often associated with other endocrine and non-endocrine autoimmune disease. The aim of this study was to evaluate antipituitary autoantibodies (APA) and antihypothalamus autoantibodies in CD children with poor clinical response to a GFD and growth hormone deficiency (GHD). We diagnosed CD on the basis of specific antibodies and endoscopic biopsies in 130 patients aged 1-15 years. Seven CD children, without catch-up growth after at least 12-months GFD, were tested for GH secretion and, in five out of seven patients, the diagnosis of GHD was made in the absence of metabolic and systemic diseases. RESULTS: APA and antihypothalamus antibodies were detected by the indirect immunofluorescence method in the seven CD children without catch-up growth factor and in 25 CD children without growth impairment matched for sex and age, and in 58 healthy children as control groups. APA resulted positive at high titres in four out of five CD-GHD patients and were also positive at low titres (<1:8) in three of only CD children and in two out of 58 controls. Hypothalamic-pituitary magnetic resonance imaging (MRI) was normal in all patients except in one with cystic pineal. APA have been previously detected not only in adults with GHD, but also in idiopathic GHD children, suggesting the occurrence of an autoimmune hypophysitis in these patients. CONCLUSION: In our study, the presence of APA in CD children without catch-up growth after GFD seems to be able to identify an autoimmune form of hypophysitis involving the somatotrophs cells.

Adolescent↗
PubMed2003

Body composition in coeliac disease adolescents on a gluten-free diet: a longitudinal study.

Our aim was to evaluate body composition in a group of coeliac disease adolescents on a gluten-free diet and to re-examine them at the end of the adolescence spurt. We studied 48 patients (group 1A), 30 age-matched healthy controls (group 2A), 11 group 1A patients after 4 years (group 1B) and 11 adolescents who were age- and sex-matched with group 1B (group 2B). Weight, height, bone mineral content, fat mass, fat-free mass (FFM) and bone mineral density were evaluated using dual-energy X-ray absorptiometry. All parameters were lower in group 1A than in group 2A subjects ( p<0.001). After 4 years, the body compartments of group 1B coeliac disease patients normalised, except for weight and FFM which remained lower than in group 2B subjects ( p<0.005). In conclusion, our study demonstrates that adolescence is a period where some parameters of body composition can still be recovered.

Absorptiometry, Photon↗
PubMed2006

The gluten-free, casein-free diet in autism: results of a preliminary double blind clinical trial.

This study tested the efficacy of a gluten-free and casein-free (GFCF) diet in treating autism using a randomized, double blind repeated measures crossover design. The sample included 15 children aged 2-16 years with autism spectrum disorder. Data on autistic symptoms and urinary peptide levels were collected in the subjects' homes over the 12 weeks that they were on the diet. Group data indicated no statistically significant findings even though several parents reported improvement in their children. Although preliminary, this study demonstrates how a controlled clinical trial of the GFCF diet can be conducted, and suggests directions for future research.

Adolescent↗
PubMed1987

Monoclonal antibody ELISA to quantitate wheat gliadin contamination of gluten-free foods.

A sensitive reproducible monoclonal antibody-based sandwich ELISA has been developed to measure the gliadin content of foods. Using the assay we have confirmed that nominally gluten-free products based on wheat starch contain trace amounts of gliadin. The level of gliadin contamination in these foods is sufficient to cause relapse of coeliac disease in specific patients. We have also examined the cross-reactivity of different cereal proteins in the assay and found good correlation with their known toxicity to patients with coeliac disease.

Animals↗
PubMed1995

The glass-transition behaviour of wheat gluten proteins.

The glass-transition behaviour of four hydrated wheat gluten proteins (alpha-gliadin, gamma-gliadin, omega-gliadin and high-molecular-weight (HMW) subunits of glutenin) was studied using differential scanning calorimetry (DSC). By fitting the data to the Gordon-Taylor equation, which has previously been used to describe the plasticization of polymers by diluents, the glass-transition temperatures (Tg) for the dry proteins were found by extrapolation. The values for Tg were within the range 397-418 K. Values for the heat capacity increment delta Cp at Tg for the plasticized proteins were also determined and ranged from 0.29-0.47 J g-1 K-1 with no dependence on water content. The differences in glass-transition behaviour of the proteins are discussed in relation to their secondary structure.

Calorimetry, Differential Scanning↗
PubMed1994

Measurement of gluten using a monoclonal antibody to a sequenced peptide of alpha-gliadin from the coeliac-activating domain I.

A monoclonal antibody, raised against a sequenced 54 amino-acid peptide from the coeliac-activating N-terminal region of alpha-gliadin, was used in an assay for the measurement of gluten in foods. A double-sandwich ELISA using a polyclonal capture antibody produced standard curves for unfractionated gliadin and its alpha, beta, gamma and omega subfractions, and for rye, barley and oat prolamins. The sensitivity of the assay for unfractionated gliadin and rye prolamins was 15 ng/ml, for barley and oat prolamins 125 and 250 ng/ml, respectively. Prolamins from coeliac non-toxic rice, maize, millet and sorghum did not cross-react in the assay.

Antibodies, Monoclonal↗
PubMed2006

Transglutaminase 2 in the enterocytes is coeliac specific and gluten dependent.

BACKGROUND: Tissue transglutaminase, the coeliac autoantigen, was shown to localise in the enterocytes of coeliac patients and controls. It was speculated that surface tissue transglutaminase has a role in the pathogenesis of coeliac disease. AIMS: To study localisation of tissue transglutaminase in different stages of coeliac disease and other enteropathies with and without villous flattening. METHODS: Immunofluorescent and immunoblotting assays were used. Duodenal cryostat sections from 23 coeliac patients (10 untreated, 8 treated, 5 potential) and 18 controls (2 autoimmune enteropathy and 16 normal duodenal mucosa) were incubated with an anti-tissue transglutaminase monoclonal antibody. Slides were blindly examined. RESULTS: The immunofluorescent assay showed that monoclonal antibody localised in the subepithelial layer, in the lamina propria, and in the pericryptal connective tissue of all samples. It also bound to surface enterocytes in 8/10 untreated, 1/8 treated, and 3/5 potential coeliac patients. None of the controls showed an epithelial distribution of tissue transglutaminase. Immunoblotting experiments performed in enterocytes freshly isolated from duodenal biopsy confirmed these findings. CONCLUSION: Epithelial distribution of tissue transglutaminase is specific for coeliac disease rather than due to a non-specific mucosal inflammation. Analysis of different stages of coeliac disease suggests that the epithelial distribution of tissue transglutaminase is gluten dependent.

Adult↗
PubMed1998

An innovative sandwich ELISA system based on an antibody cocktail for gluten analysis.

A cocktail sandwich ELISA based on the employ of two monoclonal antibodies (MAbs) as coating antibodies and a third MAb conjugated to horseradish peroxidase has been developed for the analysis of gluten in foods. Given that each MAb displays a wide specificity spectrum for wheat, barley, rye and oats prolamins, their combination for ELISA ensures a high crossreactivity with most of the potentially toxic gliadin, hordein, secalin and avenin protein family. One of the unprecedented features of the cocktail sandwich ELISA is that it permits for the first time analysis of barley hordeins in foods, which is unattainable using conventional or commercial ELISA kits. Besides, gliadins, hordeins and secalins are recognised to the same extent. The system provides a high detection sensitivity for gliadins, hordeins, secalins and avenins (1.5, 0.05, 0.15 and 12 ng/ml, respectively). The working linear range comprises 3-100 ng/ml with a gliadin detection limit of 1.5 ppm. This limit of detection is even better than that demanded in the latest Codex recommendation, 10 ppm. Cocktail ELISA data were contrasted with those of commercial ELISA kits and confirmed by mass spectrometry, a non-immunological technique which provides evidence for the occurrence of false positive results with the commercial kits.

Antibodies, Monoclonal↗