Edible vaccines: current status and future

Edible vaccines hold great promise as a cost-effective, easy-to-administer, easy-to-store, fail-safe and socioculturally readily acceptable vaccine delivery system, especially for the poor developing countries. It involves introduction of selected desired genes into plants and then inducing these altered plants to manufacture the encoded proteins. Introduced as a concept about a decade ago, it has become a reality today. A variety of delivery systems have been developed. Initially thought to be useful only for preventing infectious diseases, it has also found application in prevention of autoimmune diseases, birth control, cancer therapy, etc. Edible vaccines are currently being developed for a number of human and animal diseases. There is growing acceptance of transgenic crops in both industrial and developing countries. Resistance to genetically modified foods may affect the future of edible vaccines. They have passed the major hurdles in the path of an emerging vaccine technology. Various technical obstacles, regulatory and non-scientific challenges, though all seem surmountable, need to be overcome. This review attempts to discuss the current status and future of this new preventive modality.     

An ecological systems perspective: Its application to nutrition policy,program design and evaluation†

The ecological systems perspective is presented as an ideal model for nutrition policy formulation as well as nutrition program design and evaluation. Current nutrition policy statements in the United States are complex and unwieldy for program implementation. Action statements such as the “Dietary Goals for the U.S.” will probably not be successful because they are not based on a solid theoretical framework nor are they linked to any national policy goals which would facilitate their accomplishment.

Current nutrition program stategies may be categorized into: those programs focusing on environmental alteration or those focused at the level of the individual consumer, such as nutrition education. Each type of program strategy is unlikely to achieve ultimate success because the focus is one system or the other. By adopting an ecological systems perspective as a basic theoretical framework for nutrition policy and programs, more consistent success for improving the nutritional status of the American people might be expected.     

Assessment of heavy metal content in refined and unrefined salts obtained from Urmia,Iran

A heavy metal is any relatively dense metal that may be potentially toxic in a variety of foods. Heavy metals pollute and contaminate foods. These metals are usually toxic to human body. Heavy metals are the most important toxic metals which may cause health risks following the consumption of contaminated foods. The edible salt (NaCl) is a substance that has been used as a food additive since ancient times. Twenty samples of refined and unrefined edible salts produced in Iran were analyzed using flame atomic absorption spectrometry (FAAS) method for the presence of toxic heavy metals. The precision of the analysis was assured through the repeated analysis of the samples. The mean (±standard deviation) concentrations of toxic metals in dried samples of rock salt were as follows: Ni (1.870?±?0.850), Cd (0.328?±?0.143), Mn (0.184?±?0.230) and Co (3.124?±?0.880) mg/kg and in dry weights of samples obtained from Urmia market: Ni (1.982?±?0.021), Cd (2.461?±?0.036), Mn (0.192?±?0.028) and Co (8.450?±?0.025) mg/kg. There was a significant difference between the toxic metal concentrations and their guideline values. Therefore, it was important to assess the public health risks posed by the presence of toxic contaminants.     

Assessment of Th1 and Th2 cytokine modulatory activity of an edible fern,Diplazium esculentum

The present study was conducted to determine the effect of Diplazium esculentum on Th1 and Th2 cytokine modulation in Swiss albino mice that were administered orally with different doses of boiled D. esculentum (BDE), daily within a span of 180 days. After the treatment, serum was collected. Splenocytes were also cultured in vitro with different concentrations of BDE, and culture supernatant was collected. Both serum and culture supernatant were used for cytokine determination by enzyme-linked immunosorbent assay (ELISA) for different Th1 (IL-2 and IFN-γ) and Th2 (IL-4 and IL-10) cytokines. Results indicated significant decreases (p < 0.05, p < 0.01, and p < 0.001) in both Th1 and Th2 cytokine concentrations when compared with their respective controls. These results suggest that the intake of D. esculentum, even after cooking, may evoke immune dysfunction by altering Th1 and Th2 cytokine balance, may induce severe immunosuppression, and may be considered as alarming.     

Inhibitory effects of ergosterol isolated from the edible mushroom Hypsizigus marmoreus on TPA-induced inflammatory ear oedema and tumour promotion in mice

An antitumour-promoting activity in two-stage carcinogenesis, was found in the methanol and ethyl acetate extracts of the Japanese edible mushroom ‘Buna-shimeji’, Hypsizigus marmoreus (Tricholomataceae). From the active fractions of the extracts, two sterols, ergosterol and ergosterol peroxide, were isolated. The isolates showed inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate induced ear inflammation in mice, and ergosterol markedly inhibited tumour promotion in a two-stage carcinogenesis experiment. These sterols may be useful in developing an effective method of cancer prevention.     

药食同源药材中重金属铬的污染状况评价

目的:评价药食同源药材中重金属铬的污染状况。方法:采用微波消解-石墨炉原子吸收法测定102个药食同源药材中铬的含量,计算药材中铬的每日摄入量与世界公认准则或标准规定的限量的比值。结果:药材中铬的每日摄取量分别是美国和加拿大标准、美国EPA标准和WHO准则规定的耐受摄入量的975.0%、108.3%和78.0%。结论:102个药食药材中铬污染严重,可能会带来潜在健康风险。     

壳聚糖可食用膜对油豆角贮藏生理的影响

使用壳聚糖配制的涂膜液处理油豆角,通过测定涂膜的油豆角在贮藏期间呼吸强度、PPO、POD、MDA的变化,探讨油豆角在贮藏期间的生理变化规律.结果表明,涂膜处理后能推迟油豆角呼吸高峰的到来;同时,在贮藏期间,涂膜油豆角的呼吸强度、PPO、POD、MDA与对照组相比都有所降低.     

Fasciculation and focal loss of nerve accommodation in peripheral neuropathies

Fasciculation of muscle and repetitive response of single motor units to brief electric stimuli in diffuse demyelinative and focal (compression) neuropathies are associated with localised loss of accommodation of motor nerve fibres. The pathogenesis of spontaneous and triggered repetitive firing of neurones is discussed and it is proposed that the discrete sites of abnormally low accommodation may be in regenerating (sprouting) neurones. An improved rapid method for measuring single fibre accommodation may be used to identify regenerating neurones.     

Influence of feeding conditions on slowing of gastric emptying by edible gums

The feeding of 4% guar or xanthan gum versus 4% cellulose in a final test meal was expected to slow the gastric emptying of accompanying nutrients, and the degree of this slowing was examined in rats trained to three feeding regimens. Gastric emptying of nutrient energy was calculated from the measured disappearance of fat and of either carbohydrate or total diet residue from the stomach. In experiment 1, rats were ad libitum fed a diet containing 4% cellulose for 6 1/2 days and, after 12 to 14 hours without food, were given a test meal containing either 4% guar or 4% cellulose. In experiment 2, a growth-restricting amount of 6% and 2% guar diets was fed as a single meal on each of 7 days, and the same diets were used for the final test meals. In experiment 3, rats ate 2-hour meals containing 4% and 0% guar gum, or 4% and 0% xanthan gum, on alternate days, and again the same diets were used for the test meal. The feeding of both xanthan and guar gums in a dry form did slow gastric emptying of nutrient energy, although the feeding of 6% versus 2% guar gum was without demonstrable effect (experiment 2). The slowing effect varied with past feeding conditions, being greater in experiment 1 than in experiment 3.     

湖南笋干中微量元素的测定

采用原子吸收分光光度法测定湖南笋干中Mn、Fe、Cu、Zn、Mg、Ca等 6种微量元素 ,发现其中Mg、Fe、Zn等微量元素的含量均较高 ,远远高于 2 5种蔬菜中微量元素的含量。此结果表明 :湖南笋干中含有丰富的人体所需微量元素 ,提示湖南笋干作为天然营养补充物质 ,具有较高的营养价值。