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PubMed1983

Evidence that 2-allyl-2-isopropylacetamide, phenobarbital and 3,5-diethoxycarbonyl-1,4-dihydrocollidine induce the same cytochrome P450 mRNA in chick embryo liver.

The induction of cytochrome P450 in chick embryo liver has been studied using three different porphyrinogenic drugs, 2-allyl-2-isopropylacetamide, 3,5-diethoxycarbonyl-1,4-dihydrocollidine and phenobarbital. Pulse-labelling studies have shown that for each drug the cytochrome P450 synthesized either in ovo or in a wheat germ translation system reacted immunologically with antibody raised against the purified 2-allyl-2-isopropylacetamide-induced enzyme (Mr = 50000). To investigate whether this is due to the three drugs inducing the same protein or different proteins with common immunological determinants, nucleic acid hybridization studies have been carried out using a recently characterised 2-allyl-2-isopropylacetamide-induced cytochrome P450 cloned cDNA probe [Brooker, J. D. et al. (1982) Eur. J. Biochem. 129, 325-333]. It has been shown that the mRNA induced by each drug hybridizes with this probe and all are of similar size. The melting profile of the mRNA . cDNA hybrids indicates that the mRNAs induced by the three drugs have at least 98% homology with the cDNA probe. Restriction endonuclease digestions of total chick embryo genomal DNA and a chick cytochrome P450 genomal clone indicates that the cytochrome P450 gene homologous with the cDNA probe is represented in the genome only once. These results strongly suggest that the three drugs cause increased levels of the same cytochrome P450 mRNA, possibly due to enhanced expression of the same gene. Results are also presented which show that other cytochrome-P450-inducing drugs, 3-methylcholanthrene, beta-naphthoflavone or pregnenolone-16 alpha-carbonitrile do not increase the level of the 2-allyl-2-isopropylacetamide-inducible mRNA but rather reduce it to a level which was lower than that of the untreated controls.

Acetamides↗
PubMed2005

Emergence of a subfamily of xylanase inhibitors within glycoside hydrolase family 18.

The xylanase inhibitor protein I (XIP-I), recently identified in wheat, inhibits xylanases belonging to glycoside hydrolase families 10 (GH10) and 11 (GH11). Sequence and structural similarities indicate that XIP-I is related to chitinases of family GH18, despite its lack of enzymatic activity. Here we report the identification and biochemical characterization of a XIP-type inhibitor from rice. Despite its initial classification as a chitinase, the rice inhibitor does not exhibit chitinolytic activity but shows specificities towards fungal GH11 xylanases similar to that of its wheat counterpart. This, together, with an analysis of approximately 150 plant members of glycosidase family GH18 provides compelling evidence that xylanase inhibitors are largely represented in this family, and that this novel function has recently emerged based on a common scaffold. The plurifunctionality of GH18 members has major implications for genomic annotations and predicted gene function. This study provides new information which will lead to a better understanding of the biological significance of a number of GH18 'inactivated' chitinases.

Amino Acid Sequence↗
PubMed1972

Concanavalin A agglutination of intestinal cells from the human fetus.

Concanavalin A markedly agglutinated isolated epithelial cells from the intestine of the human fetus but not from the intestine of the adult. Wheat germ agglutinin only moderately agglutinated cells from the intestine of an adult. These results extend the studies of concanavalin A agglutination of embryonic cells to human tissue, and they suggest that concanavalin A may be reacting with a common antigen on the fetal cell membrane.

Age Factors↗
PubMed2006

Phylogenetic reconstruction of Aegilops section Sitopsis and the evolution of tandem repeats in the diploids and derived wheat polyploids.

The evolution of 2 tandemly repeated sequences Spelt1 and Spelt52 was studied in Triticum species representing 2 evolutionary lineages of wheat and in Aegilops sect. Sitopsis, putative donors of their B/G genomes. Using fluorescence in situ hybridization we observed considerable polymorphisms in the hybridization patterns of Spelt1 and Spelt52 repeats between and within Triticum and Aegilops species. Between 2 and 28 subtelomeric sites of Spelt1 probe were detected in Ae. speltoidies, depending on accession. From 8 to 12 Spelt1 subtelomeric sites were observed in species of Timopheevi group (GAt genome), whereas the number of signals in emmer/aestivum accessions was significantly less (from 0 to 6). Hybridization patterns of Spelt52 in Ae. speltoides, Ae. longissima, and Ae. sharonensis were species specific. Subtelomeric sites of Spelt52 repeat were detected only in T. araraticum (T. timopheevii), and their number and chromosomal location varied between accessions. Superimposing copy number data onto our phylogenetic scheme constructed from RAPD data suggests 2 major independent amplifications of Spelt52 and 1 of Spelt1 repeats in Aegilops divergence. It is likely that the Spelt1 amplification took place in the ancient Ae. speltoides before the divergence of polyploid wheats. The Spelt52 repeat was probably amplified in the lineage of Ae. speltoides prior to divergence of the allopolyploid T. timopheevii but after the divergence of T. durum. In a separate amplification event, Spelt52 copy number expanded in the common ancestor of Ae. longissima and Ae. sharonensis.

Base Sequence↗
PubMed1986

Cytolocalization artifacts with immunofluorescent probes.

Formaldehyde fixation, nonionic detergent extraction, and ligand binding are commonly used in conjunction with immunofluorescence microscopy to visualize antigens and lectin-reactive molecules in cytoskeletal preparations. These procedures have the potential to produce serious artifacts in cytolocalization studies, as is shown in the present investigation of wheat-germ agglutinin (WGA) binding and localization in BeWo choriocarcinoma cells. Formaldehyde fixation of intact cells reduced the binding of 125I-labeled WGA by 30% and altered the pattern of staining with fluorescein isothyocyanate (FITC)-WGA. Except for perinuclear sites which were brightly stained, the binding of FITC-WGA to other cell surface regions was significantly decreased. Nonionic detergent extractions had two different effects on lectin binding activity depending on whether or not the cells had been pretreated with lectin. In lectin-pretreated cells, 50% of bound lectin was solubilized by detergent but all of the surface binding sites appeared to be retained in active form in the detergent-insoluble residue. Nuclear-cytoskeletal monolayers prepared from cells that were not lectin pretreated lost considerable binding activity, however. These results suggest that a number of erroneous conclusions can be drawn from studies on cytoskeletal associations with membrane components using immunofluorescence microscopy on fixed and detergent-extracted cells.

Binding Sites↗
PubMed2006

Gluten-free diet: the medical and nutrition management of celiac disease.

Celiac disease (CD) is a chronic disease causing inflammation of the proximal small intestine that occurs in genetically predisposed individuals when they eat gluten, which is the storage protein in wheat, barley, and rye. The disease injury usually resolves when gluten is excluded from the diet. Although the injury will heal, the reaction to gluten is permanent and will recur with the reintroduction of gluten. The condition is surprisingly common, affecting as many as 1% of white populations. The consequences of the disease are predominantly those of malnutrition due to maldigestion and malabsorption, such as diarrhea, weight loss, and anemia. Symptoms caused by inflammation of the small intestine are also common. CD, although it is common and its pathology is well understood, frequently goes undiagnosed, probably because of the nonspecific or vague nature of many of the symptoms that occur. The cornerstone of treatment for CD is elimination of gluten from the diet. In most patients diagnosed with CD, a strict gluten-free diet (GFD) alone should result in complete symptomatic and histologic resolution of the disease and reduce risk of complications. Noncompliance with diet is the leading cause of failure to respond in patients with CD. For these reasons, thorough assessment and counseling at the time of diagnosis and ongoing care are crucial. In this article, we address briefly what is known about the pathogenesis and diagnosis of CD and address its treatment in detail.

Celiac Disease↗
PubMed1983

Local activation of the killing mechanism in PU5 antibody-dependent cell-mediated cytotoxicity effector cells.

This study was undertaken to determine whether ADCC effector cells expressed their killing mechanism globally throughout the entire cell surface or locally in a restricted area. Nonantibody-coated erythrocytes were bound to PU5 ADCC effector cells by either Con A or protein A-Ig bridges, and the effector cells with the adherent nonspecific erythrocyte target cells were mixed with specific antibody-coated erythrocytes. Our results indicated that the Con A or protein A-Ig-linked erythrocytes were not destroyed while the effector cell was in the process of killing specific antibody-coated erythrocytes. Therefore, the ADCC killing mechanisms of PU5 cells require activation by the interaction of Fc receptor with specific antibody-coated erythrocytes, and these killing mechanisms, once activated, are expressed in a locally restricted area of the effector cells rather than globally throughout the entire surfaces of the ADCC effector cell. Previously, we investigated the expression of the killing mechanism in cytolytic T lymphocytes (CTL) and found that alloimmune CTL in the process of killing specific target cells did not kill nonspecific targets linked to the CTL by either wheat germ agglutinin or immunoglobulin bridges. Thus, with respect to the surface membrane expression of lytic activity, CTL and the PU5 ADCC effector cells are similar. Our findings support the view that the various effector killing cells have a common cytolytic pathway and differ only by the recognition and triggering mechanisms.

Animals↗
PubMed2001

Suspended particulates and bioaerosols emitted from an agricultural non-point source.

Suspended particulate and bioaerosol levels were measured at three sites downwind of an agricultural non-point source during the wheat harvesting season. Suspended particulates were detected at mean values ranging from 10000 to 2420 micrograms m-3 at distances of from 20 to 60 m downwind of the source, respectively. Airborne viable bacterial counts were recorded at mean values ranging between 10(4) and 10(6) colony forming units (cfu) m-3, whereas, Gram negative (Gram -ve) bacteria varied between 10(3) and 10(5) cfu m-3. Fungi levels were detected at mean values varying between 10(5) and 10(6) cfu m-3. However, streptomycetes were found at lower counts than those recorded for viable bacteria and fungi. Total viable bacteria, Gram -ve bacteria, fungi and streptomycetes associated hay fragments were determined at mean values of 1.5 x 10(6), 1.6 x 10(3), 2.2 x 10(4) and 6 x 10(3) cfu g-1 of hay, respectively. Cladosporium, white and red yeasts as well as Alternaria were the predominant airborne fungi, whereas, Alternaria was the dominant species associated with hay fragments. Pseudomonas, Acinetobacter and Enterobacteriaceae were the dominant Gram -ve bacteria. The most common fungal genera, such as Cladosporium and Fusarium (minor short axis), as well as Streptomyces species have an aerodynamic diameter (dae) of less than 5 microns, which can penetrate and deposit in the alveoli. Farmers and nearby residents are exposed to high levels of organic dust and bioaerosols during the wheat harvesting season. This may cause health problems in exposed persons based on toxic or allergic reactions.

Aerosols↗
PubMed2004

Late eczematous reactions to food in children with atopic dermatitis.

BACKGROUND: Food allergy is a common problem in patients with atopic dermatitis (AD), particularly in children. While immediate reactions to food are well characterized, the importance of food as a provocation factor for late eczematous reactions has been a subject of debate for several decades. OBJECTIVE: To investigate the importance of food for the induction of late eczematous reactions in children with AD and to correlate the clinical outcome to the results of specific IgE determinations and atopy patch tests (APTs). METHODS: One hundred and six double-blind placebo-controlled food challenges (DBPCFCs) to cow's milk, hen's egg, wheat and soy in 64 children with AD (median age 2 years) were analysed retrospectively. Total and food-specific IgE were determined by CAP RAST FEIA and APTs with native foodstuff were performed. The diagnostic values of specific IgE and APT results were calculated. RESULTS: Forty-nine (46%) of the challenges were related to a clinical reaction. An exacerbation of AD (late eczematous reaction) commonly occurred 24 h after the ingestion of food. Isolated late eczematous reactions were seen in 12% of all positive challenges. Forty-five percent of the positive challenges were associated with late eczematous responses, which followed immediate-type reactions. The sensitivity of food-specific IgE and the APT was 76% and 70%, respectively. Specific IgE and APT were often false positive, which resulted in low positive predictive values (64% and 45%, respectively). CONCLUSIONS: Late eczematous reactions may often be observed upon food challenge in children with AD. Due to the poor reliability of food-specific IgE and APT results DBPCFCs have still to be regarded as the gold standard for the appropriate diagnosis of food responsive eczema in children with AD.

Child, Preschool↗
PubMed1983

Nutritional significance of interactions between iron and food components.

Most food iron in the gut enters into two "common pools" that behave quite differently in terms of absorption. Heme iron present in hemoglobin and myoglobin, is well absorbed and is relatively unaffected by diet composition. Non-heme iron, the form of iron present in vegetables and in man's staples, generally is poorly absorbed and is greatly affected by enhancing or inhibiting substances in the diet. In experiments employing intrinsically-labeled hemoglobin as a tracer, absorption of a dry hemoglobin concentrate added to milk, a rice cereal and wheat cookies, was uniformly good, relatively constant and quite independent from the type of food. In contrast, absorption of iron salts decreases markedly when given with food. The presence or absence of inhibiting or enhancing factors of non-heme iron absorption is determinant in the possibility of obtaining required iron for most people in the world whose diet contains little heme iron. Meat and ascorbic acid are the main enhancers of non-heme food iron absorption. Common inhibitors include carbonates, oxalates, phytate, bran, tea and egg yolk. The enhancing effect of ascorbic acid on the absorption of fortification iron in milk and the effect of tea, eggs or meat on the absorption of bread iron from common Chilean meals are discussed as examples of interactions of food components with non-heme iron.

Ascorbic Acid↗
PubMed2005

Clinical presentation of celiac disease in the pediatric population.

Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of gluten-containing grains (including wheat, rye, and barley) in genetically susceptible individuals. CD is associated with HLA molecules DQ2 (90%-95%) and DQ8 (5%-10%), and in the continued presence of gluten the disease is self-perpetuating. CD is one of the most common lifelong disorders worldwide and is characterized by a variety of clinical presentations. These include the typical malabsorption syndrome (classic symptoms) and a spectrum of symptoms potentially affecting any organ or body system (nonclassic symptoms). Because CD often is atypical or even clinically silent, many cases go undiagnosed and are exposed to the risk of long-term complications. There is growing interest in the social aspects of CD because the burden of illness related to this condition is doubtless higher than previously thought.

Adolescent↗
PubMed2006

Role of 2,4-diacetylphloroglucinol-producing fluorescent Pseudomonas spp. in the defense of plant roots.

Plants have evolved strategies of stimulating and supporting specific groups of antagonistic microorganisms in the rhizosphere as a defense against diseases caused by soilborne plant pathogens owing to a lack of genetic resistance to some of the most common and widespread soilborne pathogens. Some of the best examples of natural microbial defense of plant roots occur in disease suppressive soils. Soil suppressiveness against many different diseases has been described. Take-all is an important root disease of wheat, and soils become suppressive to take-all when wheat or barley is grown continuously in a field following a disease outbreak; this phenomenon is known as take-all decline (TAD). In Washington State, USA and The Netherlands, TAD results from the enrichment during monoculture of populations of 2,4-diacetylphloroglucinol (2,4-DAPG)-producing Pseudomonas fluorescens to a density of 10 (5) CFU/g of root, the threshold required to suppress the take-all pathogen, Gaeumannomyces graminis var. tritici. 2,4-DAPG-producing P. fluorescens also are enriched by monoculture of other crops such as pea and flax, and evidence is accumulating that 2,4-DAPG producers contribute to the defense of plant roots in many different agroecosystems. At this time, 22 distinct genotypes of 2,4-DAPG producers (designated A - T, PfY and PfZ) have been defined by whole-cell repetitive sequence-based (rep)-PCR analysis, restriction fragment length polymorphism (RFLP) analysis of PHLD, and phylogenetic analysis of PHLD, but the number of genotypes is expected to increase. The genotype of an isolate is predictive of its rhizosphere competence on wheat and pea. Multiple genotypes often occur in a single soil and the crop species grown modulates the outcome of the competition among these genotypes in the rhizosphere. 2,4-DAPG producers are highly effective biocontrol agents against a variety of plant diseases and ideally suited for serving as vectors for expressing other biocontrol traits in the rhizosphere.

Cluster Analysis↗
PubMed1976

Folate levels among various populations in central Iran.

Serum folic acid levels (Lactobacillus casei assay) were determined in 467 subjects representing various socioeconomic classes from rural and urban central Iran. Of the subjects 170 were pregnant females in different trimesters. The mean serum folate levels of the various groups studied ranged from 7.5 to 11.1 ng/ml and are within the normal reported range of 5.9 to 21.0 ng/ml. Only two subjects had serum folate levels below 3.0 to 5.9 ng/ml. In anemic subjects (hematocrit is less than 37%), red blood cell folate levels were also determined and were significantly higher than nonanemic controls (558 +/- 56 versus 346 +/- 35 ng/ml of packed red blood cells, P is less than 0.01). This difference may be related to underutilization of folate in patients with iron deficiency (a common metal deficiency in this area). A probable explanation for the well maintained serum folate levels in late pregnancy as well as in other populations studied in this report may be the high dietary intake of Iranian bread made from wheat flour of high extraction rate.

Adolescent↗
PubMed1998

Characterized allergens causing bakers' asthma.

Although airborne allergens in bakeries and confectioneries cause one of the most common forms of occupational asthma, namely, bakers' asthma, only a few of them are known in detail so far. Here we summarize current knowledge of bakery allergens and describe our own two-dimensional (2-D) immunoelectrophoresis studies of wheat-flour allergens as well as the allergenic baking enzyme Asp o 2. Out of approximately 700 soluble wheat polypeptides, 70 show IgE binding; the following wheat-flour allergens could be identified and characterized: members of the alpha-amylase inhibitor family (14-18 kDa), acyl-CoA oxidase (26 kDa), peroxidase (36 kDa), and fructose-bisphosphate aldolase (37 kDa). However, the great majority of the soluble wheat-flour allergens, mainly located in the 27-, 55-, and 70-kDa areas of the 2-D immunoblots with pI values of 5.8-6.8, 5.9-6.5, and 5.5-6.1, respectively, are not known at present. Asp o 2, to which approximately 25% of all bakers with respiratory symptoms are sensitized, is a well-characterized starch-cleaving enzyme. We conclude that great effort is still needed to describe all major wheat-flour allergens. As shown by Asp o 2, knowledge of the causative allergens and their characteristics enables us to initiate very effective preventive measures such as the introduction of granulated allergenic products.

Allergens↗
PubMed1995

Variation in the primary structure of waxy proteins (granule-bound starch synthase) in diploid cereals.

The molecular weights of waxy proteins, by SDS-PAGE, and the N-terminal amino acid sequences of mature protein and of V8 protease-induced fragments were determined in diploid cereals. The homology of the primary structure was relatively high among cereals examined here, and there appeared to be a common sequence, V-F-V-G-A-E-M-A, in the vicinity of the N terminus. Based on the amino acid sequences, these cereals could be divided into two groups, including corn and rice in one and diploid wheat, four Aegilops species, rye, and barley in the other. In diploid wheat and Aegilops species there were substitutions of amino acids in the primary structure. Variations of this sort suggest that the primary structure of waxy proteins would provide clues to the phylogenetic relations in the wheat group.

Amino Acid Sequence↗
PubMed2006

Effects of metsulfuron-methyl on the microbial population and enzyme activities in wheat rhizosphere soil.

The effects of metsulfuron-methyl, a sulfonylurea herbicide, on the wheat soil microorganisms were evaluated by the methods of microbial inoculation culture, and the activities of three enzymes were measured using the colorimetric method. The tolerant microorganisms that can resist 500 microg x g(-1) metsulfuron-methyl in the counting culture medium were studied specially. Metsulfuron-methyl distinctly inhibited the common aerobic heterotriphic bacteria, but the effects on common fungi and common actinomycete were not evident. In the meantime, the number of tolerant fungi increased greatly in the rhizosphere after the application of metsulfuron-methyl in contrast to the significant decrease of the amount of tolerant actinomycete. It indicates that fungi might turn into the dominant microbial type and actinomycete is the sensitive factor in the soil polluted by sulfonylurea residues. The population of aromatic compounds-decomposing bacteria, aerobic azotobacter, and nitrite bacteria all increased in the earlier period, but the aerobic azotobacter decreased rapidly in number 30 days later, and the amount of nitrite bacteria also showed a temporary decrease with time 15 days later. However, the denitrifying bacteria just began to increase significantly after the crops had grown for 50 days. The amount of sulfur-oxidizing bacteria gradually decreased with the growth of crops, and so were the sulfate-reducing bacteria after metsulfuron-methyl application. To all types of microorganisms, there were more microbes in rhizosphere samples than those in nonrhizosphere except aerobic azotobacter. It means the growth of wheat root system can stimulate the growth of most microorganisms. The activities of hydrogen peroxidase and polyphenol oxidase in soil samples after metsulfuron-methyl application were notably lower than those in the control, and the difference of the activities between the samples of rhizosphere and nonrhizosphere was evident. On the contrary, the activity of dehydrogenase was not inhibited by the application of metsulfuron-methyl, and the rhizosphere effect was not obvious either.

Actinobacteria↗
PubMed1990

Conformational studies of peptides corresponding to the coeliac-activating regions of wheat alpha-gliadin.

The structures of four peptides corresponding to parts of the coeliac-activating protein A-gliadin were studied by structure prediction and c.d. spectroscopy. Three of the peptides corresponded to parts of the coeliac-activating N-terminal region (residues 3-55, 3-19 and 39-45) and contained two tetrapeptide motifs common to all coeliac-active regions (Pro-Ser-Gln-Gln and Gln-Gln-Gln-Pro). The Pro-Ser-Gln-Gln sequence was also present in the fourth peptide, on the basis of the C-terminal part of the molecule (211-217). These studies showed that beta-reverse turns were the predominant structural feature in all peptides and were predominantly of type I/III in two of the N-terminal peptides and type II in the C-terminal peptide. These turns form when the peptide is dissolved in solvents of low dielectric constant (trifluoroethanol) and high dielectric constant (water and iso-osmotic saline), although their presence in the N-terminal peptides may be masked in the latter solvents due to equilibrium with a poly-L-proline II structure favoured at lower temperatures.

Amino Acid Sequence↗
PubMed1952

The isolation of wheat germ nuclei and some aspects of their glycolytic metabolism.

1. A procedure for isolating nuclei of the wheat germ in non-aqueous media has been described. 2. Such nuclei were shown to constitute about 50 per cent of the protoplasmic mass and to have a ribonucleic acid content of an order equivalent to that of the cytoplasm. 3. Studies of the distribution of the enzymes-aldolase, phosphoglyceraldehyde dehydrogenase, enolase, and pyruvate kinase-have revealed that the nuclei are the most vigorous sites of glycolytic activity. 4. Analysis of the DPN content of the nuclei in calf tissues-liver, pancreas, and heart-pointed to the probability that glycolytic activity is a characteristic common to many nuclei. 5. The significance of glycolytic activity to nuclear function has been discussed and some suggestive comparisons made between the two energy-yielding systems of glycolytic and oxidative phosphorylation.

Carbohydrates↗