Ara h2三聚体重组蛋白的制备及其低致敏原性鉴定

目的制备花生主要过敏原Ara h 2三聚体重组蛋白并检测其过敏原性。方法利用分子生物学的方法将3分子的Ara h 2依次串联起来,并将其整合到原核表达载体pET-32a(+),再转化到感受态Origami中;然后利用IPTG诱导其表达;通过Ni2+亲和层析纯化三聚体重组蛋白;Western-blotting和ELISA检测目的蛋白的过敏原性。结果测序结果表明Trimer成功整合到pET-32a(+)上。三聚体重组蛋白纯化后经SDS-PAGE鉴定,蛋白大小与理论值相符。Western-blotting和ELISA结果表明Trimer与重组的Ara h 2(r-Ara h 2)蛋白相比,结合花生过敏病人混合血清中IgE的能力有所降低。结论成功制备花生主要过敏原Ara h 2三聚体重组蛋白,初步的体外实验表明该重组蛋白具有低致敏原的潜能。     

轮状病毒抗原蛋白G3VP7基因在花生中遗传转化的研究

为提高外源蛋白的表达量和简化分离纯化过程,使用植物油体表达载体,以花生子叶节为转化受体,通过农杆菌介导将轮状病毒抗原蛋白G3VP7基因开展遗传转化的研究。从转化植株中随机选取11株表现Kan抗性植株进行PCR检测,结果有6株能扩增出特异性条带,阳性率为54.5%。对转基因植株进一步进行PCR-Southern杂交分析,发现转基因植株中有6株PCR反应呈阳性,其中有3株PCR-Southern杂交有特异性目标带出现。结果表明,外源基因已经整合到了花生基因组上。该研究为以植物为载体生产廉价、高效的植物口服疫苗奠定了基础。     

Effects of P limitation and molecules from peanut root exudates on pqqE gene expression and pqq promoter activity in the phosphate-solubilizing strain Serratia sp. S119

The mineral phosphate-solubilizing phenotype in bacteria is attributed predominantly to secretion of gluconic acid produced by oxidation of glucose by the glucose dehydrogenase enzyme and its cofactor, pyrroloquinoline quinone. This study analyzes pqqE gene expression and pqq promoter activity in the native phosphate-solubilizing bacterium Serratia sp S119 growing under P-limitation, and in the presence of root exudates obtained from peanut plants, also growing under P-limitation. Results indicated that Serratia sp. S119 contains a pqq operon composed of six genes (pqqA,B,C,D,E,F) and two promoters, one upstream of pqqA and other between pqqA and pqqB. PqqE gene expression and pqq promoter activity increased under P-limiting growth conditions and not under N-deficient conditions. In the plant–bacteria interaction assay, the activity of the bacterial pqq promoter region varied depending on the concentration and type of root exudates and on the bacterial growth phase. Root exudates from peanut plants growing under P-available and P-limiting conditions showed differences in their composition. It is concluded from this study that the response of Serratia sp. S119 to phosphorus limitation involves an increase in expression of pqq genes, and that molecules exuded by peanut roots modify expression of these phosphate-solubilizing bacterial genes during plant–bacteria interactions.     

The supplementation effects of peanut sprout on reduction of abdominal fat and health indices in overweight and obese women

BACKGROUD/OBJECTIVES

This study was conducted in order to investigate the effect of peanut sprout extracts (PSE) on health indices in overweight and obese women (BMI ≥ 23 kg/m²).

SUBJECTS/METHODS

Subjects were divided into three groups by double-blind randomized trial; the Placebo group (n = 15) and the Low PSE group (2.6 g PSE/day, n = 15), and the High PSE group (5.8 g PSE/day, n = 15). Subjects consumed 12 capsules per day, three times a day, 30 min before meals, for 4 weeks. Anthropometric data, blood biochemical variables, and dietary intake were evaluated before and after the experiments.

RESULTS

In the Low and High PSE group, the waist circumference showed a significant decrease between pre- and post-test. In the Low PSE group, the reduction of systolic blood pressure between pre- and post-test was statistically significant. Serum LDL or triglyceride levels in both Low and High PSE groups were significantly decreased, and serum alanine transaminase and aspartate transaminase were significantly decreased only in the Low PSE group. The parameters regarding erythrocyte and leucocyte counts showed no significant differences between pre- and post-test among groups, which suggested the safety of intake of peanut sprouts as a dietary supplement.

CONCLUSIONS

This study indicates that PSE supplementation improves abdominal obesity and overall health indices. Therefore, an appropriate amount of peanut sprouts may be a plausible effective agent for obesity and obesity related health problems in obese women.     

Sequential Changes in Aberrant Crypt Foci and Lectin Expression in the Early and Late Stages of DMH-Induced Colon Carcinogenesis in Rats

Background/Aims

The purpose of this study was to investigate the malignant potential of aberrant crypt foci (ACF) by measuring the multiplicity of crypts and lectin expression in the early and late stages of 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis.

Methods

Six-week-old Wistar rats were injected subcutaneously with DMH for 27 weeks. We classified ACF according to the number of crypts per ACF as a few crypts (≤3 crypts, FC ACF) or numerous crypts (≥4 crypts, NC ACF). Immunohistochemistry was used to evaluate lectin expression.

Results

In the early stage, FC ACF (590/1,902, 31.0%) occurred more frequently than NC ACF (35/449, 7.8%); whereas in the late stage, NC ACF (176/449, 39.2%) occurred more frequently than FC ACF (324/1,902, 17.0%). The number of ACF peaked at 15 to 20 weeks. The ratio of NC/FC ACF increased gradually during carcinogenesis. The expression of both UEA1 and PNA was higher in NC ACF than FC ACF. Lectin expression increased in the late stage compared with the early stage.

Conclusions

The expression of lectin was higher in NC ACF and ACF in the late stage. Therefore, ACF with higher multiplicities in the late stage may have more malignant potential in DMH-induced colon carcinogenesis.     

Phenotypical characterization of tree nuts and peanut allergies in east Mediterranean children

Introduction/ObjectivesThe characteristics of tree nuts (TNs) and peanut (PN) allergies vary in different regions of the world. We aim to identify the characteristics of TNs/PN allergies in Turkish children.Patients and MethodsA total of 227 children [4.8 (3.2–6.8) years] with TN and/or PN allergies were included. The phenotypical features of TNs/PN allergic children and the risk factors for multiple TNs/PN allergies were evaluated.ResultsAllergy to TNs/PN developed at a median age of 12.0 (10.0–18.0) months. The most common TNs/PN responsible for food allergies were the hazelnut (63.9%) and the pistachio (54.6%). Of TNs/PN allergic children, 54.2% experienced reactions with at least two types of . Current ages 6–10 years [OR:2.455, 95% CI:1.255-4.852, p = 0.009] and family history of atopy [OR:2.156, 95% CI:1.182–3.932, p = 0.012] were the risk factors for multiple TNs/PN allergies. Most of the patients with cashew nut and pistachio allergies exhibited co-sensitization and co-allergy to both of these TNs/PN. Although the rarest TNs/PN allergy was seen with almond, the possibility of allergy to other TNs or PN was highly increased in the patients with almond allergy compared to other TNs/PN.ConclusionsChildren with TNs/PN allergy living in an East Mediterranean region differ from the counterparts living in Western countries by an earlier age of onset of the TNs/PN allergy symptoms, increasing possibility to have multiple TNs/PN allergy at older ages, and different spectrum of TN/PN allergies (hazelnut followed by pistachio/cashew) that all indicate the consumption habits which are important determinants of TN/PN allergy development.     

部分市售食品中总黄曲霉毒素污染的监测结果

目的了解我国部分食品（玉米、花生、大米、核桃、松子）中黄曲霉毒素B1、B2、G1、G2的污染情况,为国家食品限量标准及国际相应控制规范的制定提供基本科学依据。方法2003年10月从重庆、福建、广东、广西、湖北、江苏、上海、浙江等地区共采集市售玉米、花生、大米、核桃、松子等样品284份。碾磨后经乙腈／水提取、过滤,提取液净化后,经三氟乙酸衍生,进行高效液相色谱测定。结果玉米中黄曲霉毒素的检出率为70．27％,平均含量为36．51μg／kg,最高为1098．36μg／kg,并有14．86％的玉米样品中黄曲霉毒素B1含量超出国家限量标准。花生中黄曲霉毒素的检出率为24．24％,平均含量为80．27μg／kg,最高为437．09μg／kg,且有3．03％的花生样品中黄曲霉毒素含量超出国家及国际食品法典限量标准。大米、核桃、松子的污染情况较轻,全部符合国家限量标准。结论玉米和花生是我国受黄曲霉毒索污染的主要食品。食品中黄曲霉毒素B。并不能全面代表总黄曲霉毒素的污染情况。进行食品中总黄曲霉毒素的污染监测,对国家制定食品限量标准及国际相应控制规范具有重要的现实意义。