Epicutaneous exposure to peanut protein prevents oral tolerance and enhances allergic sensitization

BACKGROUND: Food allergies are an important cause of life-threatening hypersensitivity reactions. Oral tolerance can be considered the default immune response to dietary antigens, with immune deviation resulting in allergic sensitization. However, primary sensitization to food allergens may not solely be through the gastrointestinal mucosa, as strong T-helper type 2 (Th2)-biased immunity can result from exposure to protein allergens on barrier-disrupted skin. OBJECTIVE: The purpose of this study was to examine whether exposure to allergens through the skin may interfere with the normal development of oral tolerance and promote allergic sensitization to food proteins. METHODS: Female BALB/c mice were exposed epicutaneously to peanut protein and induction of systemic oral tolerance through high dose feeds of peanut protein was subsequently assessed. Other mice were rendered tolerant prior to epicutaneous peanut exposure. Sensitivity to peanut was determined by assessing delayed-type hypersensitivity, proliferative, cytokine and antibody responses. RESULTS: Epicutaneous exposure to peanut protein induced potent Th2-type immunity with high levels of IL-4 and serum IgE. Primary skin exposure prevented the subsequent induction of oral tolerance to peanut in an antigen-specific manner. Upon oral challenge, mice became further sensitized and developed strong peanut-specific IL-4 and IgE responses. Furthermore, animals with existing tolerance to peanut were partly sensitized following epicutaneous exposure. CONCLUSION: Epicutaneous exposure to peanut protein can prevent induction of oral tolerance, and may even modify existing tolerance to peanut. Epidermal exposure to protein allergens selectively drives Th2-type responses, and as such may promote sensitization to food proteins upon gastrointestinal exposure.     

Caffeic acid improves the bioavailability of l‐dopa in rabbit plasma

The impacts of caffeic acid (3,4‐dihydroxycinnamic acid, CA) on the pharmacokinetics of levodopa (L‐dopa) were studied in rabbits. A single dose of 5/1.25 mg·kg^?1 l ‐dopa/carbidopa was administered alone or was co‐administered with three different doses of caffeic acid (2.5, 5, and 10 mg·kg^?1), or a single dose of 5 mg·kg^?1 caffeic acid was administered alone via an intramuscular route to six rabbits each in a crossover treatment protocol. Plasma levels of l ‐dopa, 3‐O‐methyldopa (3‐OMD), caffeic acid, and ferulic acid were determined and subsequently used to calculate their pharmacokinetic parameters. The results indicated that caffeic acid administered at a dose of 10 mg·kg^?1 decreased about 22% of the peripheral formation of 3‐OMD and about 31% of the C_max of 3‐OMD. In addition, the metabolic ratios (MR, AUC of 3‐OMD/AUC of L‐dopa) decreased by about 22%. Results also indicated that caffeic acid significantly decreased the proportion of 3‐OMD (p < 0.05). In contrast, the parameters of neither caffeic acid nor ferulic acid were significantly affected by l ‐dopa/carbidopa. In conclusion, caffeic acid at a dose of 10 mg·kg^?1 can significantly affect the COMT metabolic pathway of L‐dopa. Copyright © 2009 John Wiley & Sons, Ltd.     

Socioeconomic differences in food preference and their influence on healthy food purchasing choices

Background: Studies have shown that socioeconomic groups differ in their dietary behaviours, and it has been suggested that these differences partly account for health inequalities between social groups. To-date, however, we have a limited understanding of why socioeconomic groups differ in their dietary behaviours. This paper addresses this issue by examining the relationship between socioeconomic status, food preference (likes and dislikes) and the purchase of 'healthy' food (i.e. food consistent with dietary guideline recommendations). Methods: This study was based on a dual-sample, dual-method research design. One sample was systematically selected from the Australian Commonwealth electoral roll and the data collected using a mail-survey methodology (81% response rate, n =403). The second consisted of a convenience sample of economically disadvantaged people recruited via welfare agencies (response rate unknown, n =70). A mail survey methodology was deemed inappropriate for this sample, so the data were collected by personally delivering the questionnaire to each respondent. Results: Socioeconomic groups differed significantly in their food purchasing choices and preferences. The food choices of respondents in the welfare sample were the least consistent with dietary guideline recommendations, and they reported liking fewer healthy foods (all results were independent of age and sex). Notably, socioeconomic differences in preference explained approximately 10% of the socioeconomic variability in healthy food purchasing behaviour. Conclusion: Whilst it is not clear why socioeconomic groups differ in their food preferences, possible reasons include: reporting bias, differential exposure to healthy food as a consequence of the variable impact of health promotion campaigns, structural and economic barriers to the procurement of these foods, and subculturally specific beliefs, values, meanings, etc.     

食品中铬元素的含量分析

目的：了解常见食品中铬的含量，指导人群合理摄取铬元素，对糖尿病、动脉粥样硬化、冠心病患者的合理膳食提供理论依据。方法：用石墨炉原子吸收分光光度法测定25种食品中铬含量。选用357．9μm波长，采用二步干燥。测定回收率为92．6％--98．1％，相关系数r＝0．9987，回归方程Y＝0．0l19C 0．0766。结果：肉、蛋类中铬含量在102—532μg/kg之间，谷、豆和坚果类铬含量在104．1—355μg/kg之间，蔬菜、水果类铬合量在35．8—214．7μg/kg之间。结论：铬含量以动物性食品最高，谷类食物居中，蔬菜、水果较低。     

Influence of an acidic beverage (Coca-Cola) on the absorption of itraconazole

Objective: To evaluate the effectiveness of Coca-Cola in enhancing the absorption of itraconazole. Methods: Eight healthy volunteers were randomized to receive two treatment sequences in a two-way crossover design with a 1-week wash-out period separating each study treatment. Treatment I, the control, consisted of 100 mg itraconazole with 325 ml water. Treatment II was identical to treatment I, except that itraconazole was administered with 325 ml of Coca-Cola (pH 2.5). Results: Serum itraconazole concentrations, after administration with Coca-Cola (treatment II), were higher than after administration with water (treatment I). The mean AUC was 1.12 vs 2.02 μg · h · ml⁻¹, the mean C_max was 0.14 vs 0.31 μg · ml⁻¹and the mean t_max was 2.56 vs 3.38 h in treatments I and II, respectively. Conclusion: The absorption of itraconazole can be enhanced by Coca-Cola. Received: 4 November 1996 / Accepted in revised form: 21 January 1997     

Development and reproducibility of a tool to assess school food-purchasing practices and lifestyle habits of Australian primary school-aged children

Objective: To describe the development and reproducibility of a self‐report instrument, for use with children in years 4–6, to identify sources of food eaten during the day, and type and frequency of food purchases at school. Design: Tool development stages included formulation of content and format, expert review, piloting and a test–retest study. Subjects/setting: The pilot study included school students (n = 20) in years 4 and 5 (seven girls, mean age 9.7 ± 0.7 years) attending an Australian public primary school. The test–retest study was performed in a large metropolitan public primary school (n = 245 children, 52% female, mean age 10.7 ± 0.91 years) including children from years 4 (n = 88), 5 (n = 84) and 6 (n = 73). Statistical analysis: A Kappa statistic was used to assess level of agreement between the two time periods separated by 1 week. The results were analysed using SAS version 8.2 with each question compared at time 1 and 2. Results: The mean kappa was 0.529 using pairings from 17 questions. Values ranged from 0.18 to 0.71 (CI 0.46–0.60). Conclusions and applications: The School Eating Habits and Lifestyle Survey has been developed and pilot‐tested in primary school‐aged children and shown to have moderate stability over time. The results show that each phase of development, particularly those spent in consultation and testing, led to progressive improvement of this instrument. This process improved the quality of information produced and gave insights to self‐report of dietary intake and behaviours among children.     

MANIPULATION OF CHILDREN'S EATING PREFERENCES

Giving foods as rewards can enhance consumption of those foods, while giving rewards to induce consumption of foods can decrease subsequent consumption of those foods.     

Food and health at work–a review. The costs and benefits of a policy approach

The workplace is an important setting for health promotion and provides an ideal opportunity for shaping healthy eating patterns in occupational groups for whom inequalities have been identified (DHSS, 1980). Workplace food/health policies provide an intermediate and pragmatic step towards achieving the dietary targets set out in the Government's white paper Health of the Nation and the most recent COMA report (DoH, 1991,1992). Food/health policies have been widely adopted in the NHS (Gibson & Kallevik, 1990) and preliminary research suggests that they are an effective means of intervention (Wallis & Poulter, 1988; Frost et al., 1991). Industry has been slower to link food and health promotion to a policy making process. Surveys imply that action on healthy eating in companies often originates in the occupational health department and is based on individualistic approaches with little energy being put into preventive activities which would originate in the canteen (Mclnerney & Cooper, 1989; Poulter, 1990). Policies provide a means of balancing the environmental and educational paradigms of health promotion. If food/health policies are to grow in the private sector then industry has to be convinced that the benefits Justify the costs. Some philanthropic employers are motivated by interests other than financial gain, but others are commercially led. There is little hard evidence to demonstrate that any type of employer-sponsored healthy eating initiative provides a favourable return for investment. It has been ‘guesstimates’ and extrapolation from other situations which have provided the justification for UK companies to allocate any resources towards addressing food/health issues. In April 1990 the National Grid Company adopted a comprehensive food/health policy. This paper draws on the experiences in developing and implementing the policy document to discuss the issues around evaluative activity in a commercial setting. Views are expressed on the feasibility of measurement and the value of the informaton collected. One aim of the future should be to research this under-examined area to establish a solid body of information. This would raise the level of debate from one which is currently based on anecdotal evidence to a sounder scientific footing and, therefore, ensure the future growth of such policies in the corporate sector.     

薄层扫描法测定食物中胆固醇的含量

本文探讨食物中胆固醇的薄层光密度法的测定。用硅胶Ｇ与０．３％ＣＭＣ－Ｎａ按１：２．２比例制成薄层板，石油醚－乙醚－－冰醋酸（７：３：０．１）为展开剂，５％磷钼酸乙醇溶液显色，日本岛津ＣＳ－９１０型薄层扫描仪定量扫描，测得精神异系数（ＲＤＳ％）为２．９２。稳定性变异系数（ＲＳＤ％）为２．３５，加嘏率在８７．９５－９４．２９％范围内。与气相色谱法（其回收率在９２－１０３％范围）比较，结果相接近，该法简