Reduction of allergenicity of irradiated ovalbumin in ovalbumin-allergic mice

Egg allergy is one of the most serious of the immediate hypersensitivity reactions to foods. Such an allergic disorder is mediated by IgE antibodies stimulated by T-helper type 2 (Th2) lymphocytes. This study was undertaken to evaluate changes of allergenicity and cytokine profiles by exposure of irradiated ovalbumin (OVA), a major allergen of egg white, in the OVA-allergic mice model. OVA solutions (2 mg/ml in 0.01 M phosphate buffered saline (PBS) were gamma-irradiated to 50 and 100 kGy. The allergenicity in the OVA-allergy-induced mice model was remarkably reduced when challenged with irradiated OVA. Cultures of spleen cells harvested from OVA-sensitized mice showed a significant decrease in Th2 cytokine levels of ILs-4 and -5 with a concomitant increase in Th1 cytokine levels of IL-12 when co-cultured with irradiated OVA. However, IFN-γ level decreased dependant on the radiation dose of co-cultured OVA. The levels of IgEs and Th2-cytokine were reduced dependant on the radiation dose. These data show that the irradiated OVA could downregulate the activity of Th2 lymphocytes in OVA-sensitized mice.     

Effects of gamma irradiation on the yields of volatile extracts of Angelica gigas Nakai

The study was carried out to determine the effects of gamma irradiation on the volatile flavor components including essential oils, of Angelica gigas Nakai. The volatile organic compounds from non- and irradiated A. gigas Nakai at doses of 1, 3, 5, 10 and 20 kGy were extracted by a simultaneous steam distillation and extraction (SDE) method and identified by GC/MS analysis. A total of 116 compounds were identified and quantified from non- and irradiated A. gigas Nakai. The major volatile compounds were identified 2,4,6-trimethyl heptane, α-pinene, camphene, α-limonene, β-eudesmol, α-murrolene and sphatulenol. Among these compounds, the amount of essential oils in non-irradiated sample were 77.13%, and the irradiated samples at doses of 1, 3, 5, 10 and 20 kGy were 84.98%, 83.70%, 83.94%, 82.84% and 82.58%, respectively. Oxygenated terpenes such as β-eudesmol, α-eudesmol, and verbenone were increased after irradiation but did not correlate with the irradiation dose. The yields of active substances such as essential oil were increased after irradiation; however, the yields of essential oils and the irradiation dose were not correlated. Thus, the profile of composition volatiles of A. gigas Nakai did not change with irradiation.     

Chemical, sensory and microbiological changes of gamma irradiated coconut cream powder

A study was carried out to determine optimum decontamination dose for a locally manufactured coconut cream powder. Samples were gamma irradiated (0–15 kGy) and ageing process was achieved using GEER oven at 60 °C for 7 days, which is equivalent to one-year storage at room temperature. Iodine value (IV), ranging from 4.8 to 6.4, was not affected by radiation doses and storage, however peroxide value and thiobarbituric acid (TBA) generally increased with radiation doses. In most samples, peroxide value (meq/kg) reduced after storage, whilst the TBA (mg malonaldehyde/kg), indicator for product quality, slightly increased. The sensory evaluation conducted using 25 taste panellists indicated that scores on odour, creamy taste and overall acceptance for all irradiated samples at more than 5 kGy were significantly lower (P<0.05) than the control. However, the panellists could not detect any significant differences among the irradiation doses (P>0.05). All stored products were significantly different in colour, creamy taste, odour and overall acceptance (P<0.05) when compared to the non-stored non-irradiated control. Microbiological count of the samples prior to irradiation was in the range of 1×10²–1.7×10³ cfu/g with no detection of Salmonella sp. and Escherichia coli. No microbial colonies were detected after irradiation. Based on the TBA and overall sensory acceptance, gamma irradiation of 5 kGy was found to be the optimum dose and lower doses can be considered to decontaminate coconut cream powder.     

Ameliorative Effect of Imperatorin on Dermatophagoides pteronyssinus-Induced Allergic Asthma by Suppressing the Th2 Response in Mice

Imperatorin is a furanocoumarin derivative and an effective ingredient in several Chinese medicinal herbs. It has favorable expectorant, analgesic, and anti-inflammatory effects. In this study, we investigated whether imperatorin has protective effects against Dermatophagoides pteronyssinus (Der p)-induced asthma in mice. Lung and bronchial tissues were histopathologically examined through hematoxylin–eosin staining. The concentrations of immunoglobin E (IgE), IgG1, IgG2a in serum and those of T helper 1 (Th1) and two cytokines and eosinophil-activated chemokines in bronchoalveolar lavage fluid (BALF) were detected using an enzyme immunoassay. Histological examination revealed that imperatorin reduced inflammatory cell infiltration, mucus hypersecretion, and endothelial cell hyperplasia. The examination also indicated that imperatorin could reduce the inflammatory cell count in BALF as well as IgE and IgG1 expression in serum, but IgG2a expression was significantly increased. Imperatorin reduced the production of interleukin (IL)-4, IL-5, and IL-13 by Th2, promoted the production of interferon-γ and IL-12 by Th1, and increased the production of IL-10 in bronchoalveolar lavage fluid. These findings suggest that imperatorin has a considerable anti-inflammatory effect on Der p-induced allergic asthma in mice.     

Chitosan–iron oxide nanobiocomposite based immunosensor for ochratoxin-A

The rabbit immunoglobulin antibodies (IgGs) have been immobilized onto nanobiocomposite film of chitosan (CH)–iron oxide (Fe₃O₄₎ nanoparticles prepared onto indium–tin oxide (ITO) electrode for detection of ochratoxin-A (OTA). Excellent film forming ability and availability of –NH₂ group in CH and affinity of surface charged Fe₃O₄ nanoparticles for oxygen support the immobilization of IgGs. Differential pulse voltammettry (DPV) studies indicate that Fe₃O₄ nanoparticles provide increased electroactive surface area for loading of IgGs and improved electron transport between IgGs and electrode. IgGs/CH–Fe₃O₄ nanobiocomposite/ITO immunoelectrode exhibits improved characteristics such as low detection limit (0.5 ng dL⁻¹), fast response time (18 s) and high sensitivity (36 μA/ng dL⁻¹ cm⁻²) with respect to IgGs/CH/ITO immunoelectrode.     

Evaluation of protein content, lysine and sulfur-containing amino acids content and electrophoretic patterns of soluble proteins for gamma-irradiated semolina before and after milling of durum wheat

Influenced of gamma irradiation (0, 0.25, 1, 2.5, 5 and 10 kGy) on total nitrogen, lysine and sulfur-containing amino acids content and electrophoretic patterns of soluble proteins of semolina was studied. The effect of irradiation before and after milling on previous parameters was also investigated. Protein content of semolina was not affected with gamma irradiation before and after milling. Up to 10 kGy dose, cystine and methionine were not significantly changed, although they increased slightly with increasing irradiation dose. Lysine content decreased significantly (P≤0.05) at irradiation dose higher than 5 kGy. At 10 kGy dose, lysine decreased 5% and 14% for irradiated semolina and that obtained from irradiated wheat grains, respectively. The bands number and intensity of soluble proteins decreased with increasing irradiation dose higher than 5 kGy, as shown on SDS-PAGE electrophoresis. Irradiated semolina and semolina obtained from irradiated wheat grains at 10 kGy showed 13 and 15 bands, respectively. Unirradiated sample showed 19 bands.     

Chemically modified polymeric filtration membranes for the selective elimination of active pharmaceutical ingredients from water

Poly(ether sulfone) (PES) filtration membranes were chemically modified by ultraviolet‐assisted graft polymerization radical reactions using two monomers, namely acrylic acid (AA) and N‐vinyl‐2‐pyrrolidone (NVP). The reaction kinetics was assessed by applying increasing irradiation durations keeping the monomer concentration constant, and the degree of substitution of the produced materials was monitored by attenuated total reflection‐Fourier transform infrared spectroscopy. The selective binding properties of the produced chemically modified membranes of a series of active pharmaceutical ingredients (APIs), namely 4‐acetamidophenol (APAP), ofloxacin (OFX), ciprofloxacin (CFX), tetracycline (TC), chloramphenicol (CHPH), (±)‐propranolol (PRO) and diclofenac (DF) were evaluated by means of high‐performance liquid chromatography. It was observed that native PES membranes showed specific elimination of some of the selected pharmaceuticals (i.e. PRO, OFX, CFX and DF), and this elimination was improved after chemical modification with AA (except for DF). After chemical modification by NVP, the binding properties were partially improved for several pharmaceuticals, namely TC, CHPH and PRO, and partially reduced for OFX and CFX. The selective elimination of PRO was significantly improved with both AA‐ and NVP‐modified membranes. The reported results demonstrated that the chemical modification of PES filtration membranes allowed improving significantly their API retention properties. Copyright © 2013 John Wiley & Sons, Ltd.     

The synthesis and photoactivated cytotoxicity of 2-methyl-4-oxo-3-prop-2-yn-1-ylcyclopent-2-en-1-yl-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate conjugated with α-terthienyl derivatives

The synthesis of one pyrethroid insecticide [2-methyl-4-oxo-3-prop-2-yn-1-ylcyclopent-2-en-1-yl-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate (Abbrev. JZ) (Fig. 1)] conjugated with a series of α-terthienyl derivatives (2–8) (Fig. 1) by palladium/copper-catalyzed cross-coupling reaction is presented here for evaluating the photoactivated cytotoxicity. The photoactivated cytotoxicity on Spodoptera litura (SL) cell line was detected by MTT assay. The inhibitory activity of all the conjugates was enhanced in the irradiation condition, compared with that of JZ. The IC₅₀ values of the most effective compound 9 (Fig. 1) treated with irradiation were 11.60 μg mL⁻¹ at 24 h and 8.93 μg mL⁻¹ at 48 h, respectively. Generation of intracellular reactive oxygen species (ROS) and change of mitochondrial transmembrane potential (MMP) on SL cells treated with compound 9 were used for the further photoactivated study. A summary of these experiments on compound 9 demonstrated the notable ROS generation and dramatic MMP decrease when irradiated with UVA light. The results also represented statistically significant difference between dark and irradiation treatment of compound 9. However, in control and JZ groups, the effects were not statistically different. It was proved that our prepared compounds were ideal candidates for new photoactivated pyrethroid insecticides.     

Radiation grafting of pH and thermosensitive N-isopropylacrylamide and acrylic acid onto PTFE films by two-steps process

Polytetrafluoroethylene (PTFE) was grafted (g) with acrylic acid (AAc) by γ-ray pre-irradiation method to get PTFE-g-AAc films, then N-isopropylacrylamide (NIPAAm) was grafted onto PTFE-g-AAc films with γ-ray to get (PTFE-g-AAc)-g-NIPAAm. PTFE films were irradiated in air at a dose rate of 3.0 kGy h^–1 and different radiation dose. The irradiated films were placed in glass ampoules, which contained aqueous solutions with different monomer concentration (AAc), and then they were heated at different temperatures and reaction time. NIPAAm onto PTFE-g-AAc was carried out with the same procedure with monomer concentration of 1 mol L⁻¹. The thermosensitivity of the samples was defined and calculated as the ratio of the grafted samples swelling at 28 and 35 °C, and pH sensitivity defined as the ratio of the grafted samples swelling at pH 2 and 8.     

The identification of irradiated seasoned filefish (Thamnaconus modestus) by different analytical methods

Dried seasoned filefish (Thamnaconus modestus) was irradiated at 0–10 kGy and the identification of irradiation treatment was investigated by analyzing the characteristics of thermoluminescence (TL), hydrocarbon (HC), and 2-alkylacyclobutanone (2-ACB). The TL (TL₁), glow curve of the irradiated samples peaked at approximately 150 °C with high intensity, but that of the non-irradiated samples peaked at about 300 °C with little intensity, thus making it possible to discriminate between irradiated and non-irradiated samples. Moreover, TL ratio (TL₁/TL₂), through normalization steps, enhanced the reliability of the TL₁ results. Six kinds of HCs and three kinds of 2-ACBs quantitatively determined for the samples linearly increased in proportion to irradiation doses. In particular, two HCs like 1-hexadecane and 1,7-hexadecadine, and three ACBs, such as 2-dodecylcyclobutanone, 2-(5′-tetradeceyl)cyclobutanone, and 2-tetradecylcyclobutanone, were identified only in the irradiated samples as radiation-induced markers.     

Differential immuno-kinetic assays of allergen-specific binding for peanut allergy serum analysis

A label-free nanoparticle array platform has been used to detect total peanut allergen-specific binding from whole serum of patients suffering from peanut allergy. The serum from 10 patients was screened against a four-allergen panel of cat and dog dander, dust mite and peanut allergen protein Ara h1. The IgE and IgG contributions to the total specific-binding protein load to Ara h1 were identified using two secondary IgG- and IgE-specific antibodies and were found to contribute less than 50?% of the total specific protein load. The total mass of IgE, IgE and the unresolved specific-binding protein ΔsBP for Ara h1 provides a new serum profile for high-RAST-grade patients 5 and 6 with the IgG/IgE ratio of 4?±?2 and ΔsBP/IgE ratio of 17?±?11, neither of which is protective for the small patient cohort.

离子交换介孔分子筛DEAE-SBA-15的制备及其用于分离纯化粉尘螨主要变应原Derf2

通过3-含氧缩水甘油基-丙基-三甲氧基硅烷(GPTS)将二乙胺基乙基(DEAE)嫁接在介孔分子筛SBA-15的表面,制得弱阴离子交换层析剂DEAE-SBA-15,使其既具有分子筛作用,又具有离子交换作用的特点.经DEAE-SBA-15层析后,从粉尘螨代谢培养基中获得单一的洗脱峰,SDS-PAGE显示一条谱带,其相对分子质量为14000,表明经分离纯化所得到的蛋白质是粉尘螨主要变应原Derf2.对螨性哮喘患者皮肤点刺试验表明,所得Derf2仍具有变应原活性,且仅通过一次柱色谱即得Derf2,表明DEAE-SBA-15是一种较好的离子交换层析剂.     

A chemiluminescence and fluorescence spectroscopy study: An investigation of photocrosslinking processes in polymer systems

Chemiluminescence emission is shown to be a valuable method for the analysis and monitoring of the photochemical transformation process in BZMA-co-S copolymers. BZMA-co-S copolymer films are synthesized and irradiated at λ > 400 nm, in order to induce the phototransformation of benzyl (BZ) to benzoyl peroxide (BP) pendant groups, resulting in thermal decomposition and crosslinking. The chemiluminescence emission increases with irradiation time, and is shown to be related to the benzoyl peroxide moieties generated during irradiation. The increase in chemiluminescence intensity is interrupted at longer periods of irradiation, when the concentration of these species tends to a nearly constant value. In this case, others factors are considered to influence the chemiluminescence emission, for example the increasing crosslinking on irradiated samples, which would restrict the mobility of radicals to recombine due to crosslinking of the network.A good correlation between fluorescence, FTIR and CL measurements during photochemical formation and thermal decomposition of peroxides is found. In this work, an intramolecular excimer forming fluorescent probe, DiPyM, is also used to analyse the crosslinking process. The results obtained contribute significantly to the development of chemiluminescence as a highly sensitive methodology for assessing the photocrosslinking of a polymeric material in the early stages of the process and is due to its sensitivity in comparison to that of fluorescence analysis.     

Enhanced immunodetection of blotted house dust mite protein allergens on nitrocellulose following blocking with Tween 20

The effect of blocking nitrocellulose membranes with the nonionic detergent Tween 20 on the detection, by protein blotting, of IgE-binding to house dust mite Dermatophagoides pteronyssinus allergens has been investigated. Tween blocking led to enhanced immunodetection of allergens despite removal of proteins from the membrane when compared to protein blocking agents which did not displace transferred components. The enhancement varied with the different mite components and, for one in particular, antigen Der p II, an increase of more than 100-fold in IgE antibody binding occurred despite a concurrent loss of more than 90% of Der p II from the membrane. Both the enhancement of binding and loss of components from the membrane were dependent upon the time course of blocking and the concentration of Tween used.     

Voltammetry of immobilized cytochrome c on novel binary self-assembled monolayers of thioctic acid and thioctic amide modified gold electrodes

Horse heart cytochrome c (cyt c) was adsorbed on the binary self-assembled monolayers (SAMs) composed of thioctic acid (T-COOH) and thioctic amide (T-NH₂) at gold electrodes via electrostatic interaction. The cyt c adsorbed on the modified gold electrode exhibited well-defined reversible electrochemical behavior in 10 mM phosphate buffer solution (PBS, pH 7.0). The surface concentration (Γ) of electroactive species, cyt c, on the binary SAMs was higher than that in single-component SAMs of T-COOH, and reached a maximum value of 9.2 × 10⁻¹² mol cm⁻² when the ratio of T-COOH to T-NH₂ in adsorption solution was of 3:2, and the formal potential (E^0′=(E_pa+E_pc)/2) of cyt c was −0.032 V (vs. Ag|AgCl (3 M NaCl)) in a 10 mM PBS. The interaction between cyt c and the binary SAMs made the E^0′ shift negatively when compared with that of cyt c in solution (+0.258 V vs. NHE, i.e., +0.058 V vs. Ag|AgCl (3 M NaCl)). The fractional coverage of bound cyt c was a 0.64 theoretical monolayer. The standard electron transfer rate constant of cyt c immobilized on the binary SAMs was also higher than that on single-component SAMs of T-COOH, and the maximum value of 15.8 ± 0.6 s⁻¹ was obtained when the ratio of T-COOH to T-NH₂ in adsorption solution was at 3:2. The results suggest that the electrode modified with the binary SAMs functions better than the electrode modified with single-component SAMs of T-COOH.     

Epitope peptides and immunotherapy

Allergic diseases affect atopic individuals, who synthesize specific Immunoglobulins E (IgE) to environmental allergens, usually proteins or glycoproteins. These allergens include grass and tree pollens, indoor allergens such as house dust mites and animal dander, and various foods. Because allergen-specific IgE antibodies are the main effector molecules in the immune response to allergens, many studies have focused on the identification of IgE-binding epitopes (called B cell epitopes), specific and minimum regions of allergen molecules that binds to IgE. Our initial studies have provided evidence that only four to five amino acid residues are enough to comprise an epitope, since pentapeptide QQQPP in wheat glutenin is minimally required for IgE binding. Afterwards, various kinds of B cell epitope structures have been clarified. Such information contributes greatly not only to the elucidation of the etiology of allergy, but also to the development of strategies for the treatment and prevention of allergy. Allergen-specific T cells also play an important role in allergy and are obvious targets for intervention in the disease. Currently, the principle approach is to modify B cell epitopes to prevent IgE binding while preserving T cell epitopes to retain the capacity for immunotherapy. There is mounting evidence that the administration of peptide(s) containing immunodominant T cell epitopes from an allergen can induce T cell nonresponsiveness (immunotherapy). There have been clinical studies of peptide immunotherapy performed, the most promising being for bee venom sensitivity. Clinical trials of immunotherapy for cat allergen peptide have also received attention. An alternative strategy for the generation of an effective but hypoallergenic preparation for immunotherapy is to modify T cell epitope peptides by, for example, single amino acid substitution. In this article, I will present an overview of epitopes related to allergic disease, particularly stress on allergen specific immunotherapy. In addition, our ongoing study of immunotherapy by 'eating' T cell epitope peptides will be described. Eating T cell epitope peptides as food provides a more practical way of inducing tolerance and a challenge to prevent allergy in daily life, as opposed to therapy by ingesting peptides as medicine.     

Pulsed laser-induced oxygen deficiency at TiO2 surface: Anomalous structure and electrical transport properties

We have studied pulsed laser-induced oxygen deficiencies at rutile TiO₂ surfaces. The crystal surface was successfully reduced by excimer laser irradiation, and an oxygen-deficient TiO_2−δ layer with 160 nm thickness was formed by means of ArF laser irradiation at 140 mJ/cm² for 2000 pulses. The TiO_2−δ layer fundamentally maintained a rutile structure, though this structure was distorted by many stacking faults caused by the large oxygen deficiency. The electrical resistivity of the obtained TiO_2−δ layer exhibited unconventional metallic behavior with hysteresis. A metal–insulator transition occurred at 42 K, and the electrical resistivity exceeded 10⁴ Ω cm below 42 K. This metal–insulator transition could be caused by bipolaronic ordering derived from Ti–Ti pairings that formed along the stacking faults. The constant magnetization behavior observed below 42 K is consistent with the bipolaronic scenario that has been observed previously for Ti₄O₇. These peculiar electrical properties are strongly linked to the oxygen-deficient crystal structure, which contains many stacking faults formed by instantaneous heating during excimer laser irradiation.     

UV exposure alters respiratory allergic responses in mice

We have tested the hypothesis that exposure to ultraviolet light would inhibit T helper-1 (Th1) responses and stimulate T helper-2 (Th2) responses, and that thus in a mouse model of allergic (i.e. extrinsic) asthma (using ovalbumin [OVA] as the allergen) increased symptoms would be observed, while in a model of Th1-dependent occupational asthma (in which picryl chloride is the allergen) decreased symptoms would be observed. Whereas reduced interferon (IFN)-gamma production, decreased inflammatory responses in the airways, and reduced airway reactivity to nonspecific stimuli were observed in UV-preexposed picryl chloride sensitized and challenged mice, the results in the OVA model were less clear. Increased interleukin (IL)-10 production as a result of UV exposure was observed, together with unchanged IL-4 and IFN-gamma. In addition, decreased OVA-specific immunoglobin, IgG1 and IgE, titers were noted, as well as decreased nonspecific airway hyperreactivity. Eosinophilic inflammatory responses were not influenced. The results indicate that UV exposure can have systemic effects that influence ongoing immune responses in the respiratory tract. The effects are not only restricted to immune responses that are predominantly Th1 dependent (i.e. pulmonary delayed-type hypersensitivity and IFN-gamma production in response to picryl chloride) but also to immune response that are predominantly Th2 dependent, i.e. decreased specific IgE titers.