Food Allergy,Oral Tolerance and Immunomodulation—Their Molecular and Cellular Mechanisms

This paper describes the molecular and cellular mechanisms of food allergy and oral tolerance including immunomodulation. Food allergy is triggered by an aberrant immune response elicited by oral administration of dietary antigens. Oral tolerance is a state of immunological unresponsiveness induced by oral administration of dietary antigens and is thought to serve to suppress food allergy. This review first describes the characteristic properties of T and B cells relating to milk allergy and also the location of binding sites to T and B cells on allergen molecules. The immunogenicity of allergens is shown to be reduced by the modulations of the T cell binding site, using sophisticated methods such as site-specific mutagenesis. Furthermore, this review focuses on oral tolerance with special reference to the identification of lymphocyte compartment subsets and the immunological mechanism relating to oral tolerance. Finally, the application of oral tolerance for the treatment of allergy is speculated on.     

The Impact of Cormorants on Plant–Arthropod Food Webs on Their Nesting Islands

This study investigated the effects of cormorant colonies on plant–arthropod island food webs, the consequences of nutrient-rich runoff on marine communities, and feedback loops from marine to terrestrial ecosystems. Terrestrial plant responses were as expected, with the highest plant biomass on islands with low nest density and the highest nitrogen (N) content on islands with high nest density. In contrast to our hypothesis, we found no uniform density response across guilds. Among herbivores, the variable responses may depend on the relative importance of plant quality or quantity. As expected, nutrient-rich runoff entered water bodies surrounding cormorant nesting islands, but only at high nest density, and increased the density of emerging insects. This created a potential feed-back loop to spiders (major terrestrial predators), where stable isotope analyses suggested great use of chironomids. Contrary to our expectation, this potential feed-back did not result in the highest spider density on islands with a high cormorant nest density. Web spiders showed no changes in density on active cormorant islands, and lycosids were actually less abundant on active cormorant islands compared to reference islands. The variable response of spiders despite increased dipteran densities, and also in other consumer groups, may be due to direct negative effects of cormorants on soil chemistry, vegetation cover, and other density regulating forces (for example, top–down forces) not studied here. This study highlights the importance of including processes in the surrounding marine ecosystem to understand the impacts of seabirds on the food web structures of their nesting islands.     

Canadians’ Perceptions of Food,Diet, and Health – A National Survey

Background

Poor nutrition is harmful to one’s health as it can lead to overweight and obesity and a number of chronic diseases. Understanding consumer perceptions toward diet and nutrition is critical to advancing nutrition-related population health interventions to address such issues. The purpose of this paper was to examine Canadians’ perceived health and diet status, compared to their actual health status, and general concern about their own diet and beliefs about health. Also analyzed were some of the perceived barriers to eating “healthy” foods, with a focus on the availability of “healthy” processed foods.

Methods

Two surveys were administered online to a group of Canadian panelists from all ten provinces during May 2010 to January 2011. Thirty thousand were invited; 6,665 completed the baseline survey and 5,494 completed the second survey. Panelists were selected to be nationally representative of the Canadian adult population by age, sex, province and education level, according to 2006 census data.

Results

Approximately one third of Canadians perceived their health or diet to be very good while very few Canadians perceived their health or diet to be very poor. While the majority of Canadians believed food and nutrition to be very important for improving one’s health, fewer Canadians were concerned about their own diets. The majority of Canadians reported difficulty finding “healthy” processed foods (low in salt and sugar and with sufficient vitamins and minerals). Many also reported difficulty finding healthy foods that are affordable.

Conclusion

Although consumers believe that nutrition is one of the most important factors for maintaining health, there are still a number of attitudinal and perceived environmental barriers to healthy eating.     

Synthesis of 3′-Thioribouridine, 3′-Thioribocytidine,and Their Phosphoramidites

Abstract

3′-Thio-3′-deoxyribonucleosides (U and C) have been synthesized via Vorbruggen-type glycosylation with 3-S-benzoyl-5-O-toluoyl-1,2-O-diacetylfuranose, which was obtained from 1,2-O-isopropylidene-5-O-toluoyl-3-O-trifluoromethanesulfonyl-α-D-xylofuranose. 3′-Thio-3′-deoxyuridine has been converted to its phosphoramidite.     

Food,microhabitat, or both? Macroinvertebrate use of leaf accumulations in a montane stream

1. Leaf packs in streams may serve as food and substrate to many macroinvertebrates, but the relative importance of these two functions has not been disentangled. To test the hypothesis that leaf packs are colonized primarily for their food value rather than as microhabitat, the colonization of leaf packs of red alder and of polyester cloth in a natural stream was compared. 2. Species of shredders showed large differences in the colonization of the two types of leaf pack with almost no use of artificial leaf packs. Non-shredders were also more abundant on natural leaf packs, however, they colonized artificial leaf packs six to eighty times proportionally more than shredders. 3. The effect of different leaf types was virtually eliminated for non-shredders when the amount of fine parriculate detritus (food for many non-shredders) trapped in the leaf pack was added to the analysis as a covariate. Therefore, to non-shredders, leaf types differed only in the retention of fine particulate organic matter. 4. Comparisons of the use of both kinds of leaf packs in riffles versus pools revealed that significantly fewer animals colonized pool leaf packs. 5. These results suggest that food value, and not microhabitat, is the primary determinant of leaf pack use for most shredders and non-shredders.     

Food habits of three carnivores in a mosaic landscape of São Paulo state,Brazil

São Paulo is the most developed state in Brazil, but despite intense land use changes, some mammal species still inhabit remnant fragments of native vegetation of the state. We used fecal analyses to investigate prey diversity, trophic niche breadth, and trophic niche overlap of pumas, ocelots, and maned wolves in protected and non-protected areas in São Paulo state. During 18 months, we inspected more than 10,000 km of roads and trails and collected 233 fecal samples. Maned wolves showed generalist food habit, ocelots were predominantly carnivores, and pumas were strict carnivores. The European hare, an exotic species which had not yet been reported in the study area, was identified in the feces of a puma. Trophic niche breadth was the lowest for maned wolves (BA?=?0.339) and the highest for pumas (BA?=?0.723). Trophic niche overlap was high between maned wolves and ocelots (O_jk?=?0.765) and between pumas and ocelots (O_jk?=?0.639). Significantly different diets of maned wolves and ocelots were observed between dry and rainy seasons. Our findings indicate that these three species may adapt their diets to the disturbed landscapes. This is the second study characterizing food habits of ocelots in Cerrado areas but the first considering a large number of samples.     

Does Colour of the Food Attract Ants?

Milky white, brown, yellow and pink sugar grains along with normal sugar grains in equal number were offered to the ants at different sites, in the foraging ground of a garden locating at Garia, Kolkata, India to note the role of colouration of the food in food selection, if any. It is revealed that the ants Anoplolepis gracilipes procured all the supplied colour sugar grains from the offered sites between 1 and 43 min and the normal sugar grains between 1 and 38 min from the offered sites. Results of statistical analyses clearly indicate that the colour of the food has no role to attract the ants A. gracilipes in respect to procurement times of the sugar grains noted. This suggests that the colour of the food does not act as an attractant for the ants A. gracilipes in food selection.     

Production of the Carotenoids Lycopene, β-Carotene,and Astaxanthin in the Food Yeast Candida utilis

The food-grade yeast Candida utilis has been engineered to confer a novel biosynthetic pathway for the production of carotenoids such as lycopene, β-carotene, and astaxanthin. The exogenous carotenoid biosynthesis genes were derived from the epiphytic bacterium Erwinia uredovora and the marine bacterium Agrobacterium aurantiacum. The carotenoid biosynthesis genes were individually modified based on the codon usage of the C. utilis glyceraldehyde 3-phosphate dehydrogenase gene and expressed in C. utilis under the control of the constitutive promoters and terminators derived from C. utilis. The resultant yeast strains accumulated lycopene, β-carotene, and astaxanthin in the cells at 1.1, 0.4, and 0.4 mg per g (dry weight) of cells, respectively. This was considered to be a result of the carbon flow into ergosterol biosynthesis being partially redirected to the nonendogenous pathway for carotenoid production.Carotenoids are yellow, orange, and red pigments which are widely distributed in nature (3). Industrially, carotenoid pigments such as β-carotene are utilized as food or feed supplements. β-Carotene is also a precursor of vitamin A in mammals (11). Recently, carotenoids have attracted greater attention, due to their beneficial effect on human health: e.g., the functions of lycopene and astaxanthin include strong quenching of singlet oxygen (12), involvement in cancer prevention (2), and enhancement of immune responses (6). Astaxanthin has also been exploited for industrial use, principally as an agent for pigmenting cultured fish and shellfish.The genes responsible for the synthesis of carotenoids such as lycopene, β-carotene, and astaxanthin have been isolated from the epiphytic Erwinia species or the marine bacteria Agrobacterium aurantiacum and Alcaligenes sp. strain PC-1, and their functions have been elucidated (13, 14). The first substrate of the encoded enzymes for carotenoid synthesis is farnesyl pyrophosphate (diphosphate) (FPP), which is the common precursor for the biosynthesis of numerous isoprenoid compounds such as sterols, hopanols, dolicols, and quinones. The ubiquitous nature of FPP among yeasts has been utilized in the microbial production of lycopene and β-carotene by the yeast Saccharomyces cerevisiae carrying the Erwinia uredovora carotenogenic genes (19). However, the amount of carotenoids produced in these hosts was only 0.1 mg of lycopene and 0.1 mg of β-carotene per g (dry weight) of cells, respectively.The edible yeast Candida utilis is generally recognized as a safe substance by the Food and Drug Administration. Large-scale production of the yeast cells has been developed with cheap biomass-derived sugars as the carbon source for the production of single-cell protein and several chemicals such as glutathione and RNA (1, 4). This yeast was also found to accumulate a large amount of ergosterol in the cell during stationary phase (6 to 13 mg/g [dry weight] of cells) (17). Thus, C. utilis has the potential to produce a large amount of carotenoids by redirecting the carbon flux for the ergosterol biosynthesis into the nonendogenous pathway for carotenoid synthesis via FPP. Previously, a C. utilis strain was made to produce lycopene (0.8 mg/g [dry weight]) by expressing the three nonmodified genes crtE, crtB, and crtI derived from E. uredovora (15).In this paper, the de novo biosynthesis of lycopene, β-carotene, and astaxanthin has been performed in C. utilis by using six carotenogenic genes, which were synthesized according to the codon usage of the C. utilis glyceraldehyde-3-phosphate dehydrogenase (GAP) gene, which is expressed at high levels. By this approach, increased carotenoid production in C. utilis was achieved.     

The Immediate Influence of a Food Safety Incident on Japanese Consumers’ Food Choice Decisions and Willingness to Pay for Safer Food

In January 2008, 10 people from three families living in Chiba and Hyogo Prefectures in Japan were found to be poisoned after eating frozen dumplings that had been imported from Tianjin, China. This incident had a big influence in the short term on Japanese consumers’ consumption choice of imported food from China as well as the willingness to pay (WTP) for food with higher safety guarantees. Using data from a Web-survey of 1500 respondents covering the whole of Japan, two regression models show that firstly, after the incident, consumers intending to buy Chinese food products reduced from 92.5% to 27.6%, and the change of purchase decision is mostly affected by consumers’ prior risk perception and attitude about Chinese products and presents a regional difference. Secondly, Japanese consumers are willing to pay 64,300 yen per year for safer food on average after the incident, and those whose purchase decision is influenced by the incident have a higher WTP of 54,000 yen than those who are not influenced. The most significant factor to decide the WTP is the framing of questions in the survey. The influence of demographic factors is less important and inconsistent in the two models.     

Spatial Imprint of Food Consumption: A Historical Analysis for Sweden, 1870–2000

Depending on quantity and composition of food as well as on production conditions and techniques, the space needed to sustain an individual’s nourishment varies. The amount of space needed also depends on the use of resources such as energy, water, and fertilizers, as well as potential land degradation and water pollution. Our study focuses on the changing spatial imprint of an average inhabitant of an expanding Swedish city, Linköping, from 1870 to 2000 taking into account both shifts in consumption as well as agricultural productivity and practices. Despite the distinctly larger amount of animal food products, such as meat and fish, consumed in 2000, we calculate the area needed to sustain an individual’s annual food consumption could be less than one fourth of that needed in 1870. However, if the import of various globally produced foods is included in our calculations, the land needed to sustain the consumption of an inhabitant of Linköping in 2000 doubles. We also argue that an examination of this regional imprint can be used to explore and evaluate possibilities for regional development.     

Effects of Moranoline, 4-O-α-D-Glucopyranosylmoranoline and Their N-Substituted Derivatives on Thermostability of Cyclodextrin Glycosyltransferase,Glucoamylase, and β-Amylase

In repeated glycosylmoranolines synthetic reaction at 55°C, cyclodextrin glycosyltransferase (CGT-ase, EC 2.4.1.19) from Bacillus stearothermophilus retained its activity for more than 600 days. A main stabilizing compound. was found to be 4-O-α-D-glucopyranosylmoranoline.

The thermostabilizing activities of moranoline, 4-O-α-D-glucopyranosylmoranoline, and their N-substituted derivatives were studied. Moranoline and its N-substituted derivatives stabilized glucoamylase. 4-O-α-D-Glucopyranosylmoranoline and its N-substituted derivatives stabilized CGT-ase and β-amylase.     

In Vitro Survey of α-Glucosidase Inhibitory Food Components

A survey of food components with α-glucosidase (AGH) inhibitory activity was conducted to identify a prophylactic effect for diabetes in food. Sardine muscle hydrolyzed by alkaline protease showed potent activity (IC₅₀ = 48.7mg/ml) as well as green and oolong teas (IC₅₀ = 11.1 and 11.3mg/ml, respectively). Furthermore, hydrolyzates prepared by various proteases gave differing AGH inhibitory activity. DEAE-Sephadex chromatography of the alkaline protease hydrolyzate eluted potent AGH inhibitors (IC₅₀ = 15.6mg/ml) with a 50 mm phosphate buffer (pH 7.0) containing 0.3 m NaCl, and their subsequent separation by HPLC in an ODS column showed that there were some inhibitors possessing primary amino groups. This indicates that they would have been high anionic and peptidic compounds.     

Modular Organization of α-Toxins from Scorpion Venom Mirrors Domain Structure of Their Targets,Sodium Channels

To gain success in the evolutionary “arms race,” venomous animals such as scorpions produce diverse neurotoxins selected to hit targets in the nervous system of prey. Scorpion α-toxins affect insect and/or mammalian voltage-gated sodium channels (Na_vs) and thereby modify the excitability of muscle and nerve cells. Although more than 100 α-toxins are known and a number of them have been studied into detail, the molecular mechanism of their interaction with Na_vs is still poorly understood. Here, we employ extensive molecular dynamics simulations and spatial mapping of hydrophobic/hydrophilic properties distributed over the molecular surface of α-toxins. It is revealed that despite the small size and relatively rigid structure, these toxins possess modular organization from structural, functional, and evolutionary perspectives. The more conserved and rigid “core module” is supplemented with the “specificity module” (SM) that is comparatively flexible and variable and determines the taxon (mammal versus insect) specificity of α-toxin activity. We further show that SMs in mammal toxins are more flexible and hydrophilic than in insect toxins. Concomitant sequence-based analysis of the extracellular loops of Na_vs suggests that α-toxins recognize the channels using both modules. We propose that the core module binds to the voltage-sensing domain IV, whereas the more versatile SM interacts with the pore domain in repeat I of Na_vs. These findings corroborate and expand the hypothesis on different functional epitopes of toxins that has been reported previously. In effect, we propose that the modular structure in toxins evolved to match the domain architecture of Na_vs.     

Livelihood Diversity, Food Security and Resilience among the Caiçara of Coastal Brazil

To analyze the relationships between local livelihoods and vulnerability to food insecurity, using a resilience approach, we interviewed 350 households from seven mixed-heritage Caiçara communities in Paraty, Brazil. Fishing was a livelihood activity for 70 % of the households, and the main declared activity for 16 %. Fishing was combined with other activities such as day-wage jobs, tourism, agriculture, and commerce. Livelihood activities were not homogeneously distributed among communities, and a higher proportion of fishing households were found in generalist communities. Food insecurity appeared to be transitory (and not chronic), and fishing is central to food security. Small-scale fisheries cannot be seen in isolation from the diversity of activities that make up the livelihood portfolios of coastal communities. In view of rapid change in the area, pressures from protected areas, large-scale fisheries, tourism development and economic change in general, threaten the resilience of Caiçara livelihoods, with implications for future food insecurity.     

Investigation of the Relationship between the Lectin Activity of Azospirilla and Their α-Glucosidase, β-Glucosidase,and β-Galactosidase

The activities of -glucosidase, -glucosidase, and -galactosidase were studied during the isolation and purification of lectins from Azospirillum brasilenseSp7 and Azospirillum lipoferum59b cells. These enzymatic activities were revealed in crude extracts of surface proteins, protein fraction precipitated with ammonium sulfate or ethanol–acetone mixture, and protein fraction obtained by gel filtration on Sephadex G-75. The distribution of the enzymes between different protein fractions varied for the azospirilla studied. The cofunction of the A. brasilenseSp7 lectin and -galactosidase on the cell surface is assumed. A strong interaction between the A. lipoferum59b lectin and glucosidases was revealed. The lectin from A. lipoferum59b may possess saccharolytic activity.     

Disinfection in Food Processing – Efficacy Testing of Disinfectants

The key to effective cleaning and disinfection of food plants is the understanding of the type of the soil to be removed from the surfaces. An efficient cleaning and disinfection procedure consists of a sequence of rinses using good quality water with application of detergents and disinfectants. Disinfection is required in food plant operations, where wet surfaces provide favourable conditions for the growth of microbes. The efficacy of disinfectants is usually determined in suspensions, which do not mimic the growth conditions on surfaces where the agents are required to inactivate the microbes. Therefore, the suspension tests do not give adequate information and reliable carrier tests, which mimic surface growth, are needed. In developing a proposal for the testing of disinfectants on surfaces to an analytical standard, it is important to identify the major sources of variation in the procedure. In response to the need for a relatively realistic, simple and reliable test for disinfectant efficacy a method for culturing laboratory model biofilms has developed. The use of artificial biofilms i.e. biofilm-constructs inoculated with process contaminants in disinfectant testing can also be used for screening the activity of various disinfectants on biofilm cells. Both biofilm carrier tests showed clearly that the biofilm protects the microbes against the disinfectants. The chemical cleanliness is also essential in food plants. The total cleanliness of the process lines is mainly based on measuring the microbial load using culturing techniques. These results can give an incorrect picture of the total cleanliness, because the viable microbes do not grow when disinfectants are left on the surface. The luminescent bacteria light inhibition method offers a useful alternative for testing chemical residue left on surfaces after cleaning and disinfection operations.     

Chemoenzymatic Syntheses of Homo‐ and Heterodimers of AZT and d4T,and Evaluation of Their Anti‐HIV Activity

Homo‐ and heterodimers of AZT and d4T, possessing carbonate and carbamate linkers, have been synthesized with the aim to enhance the antiviral activity of their components. Homo‐ and heterodimer carbamates showed weak anti‐HIV activity. On the other hand, dinucleoside carbonates showed marked antiviral activity.