桑椹籽油的降脂作用研究注

目的研究桑椹籽油的降脂作用;方法普通基础饲料加10%猪油、l%胆固醇,0.5%胆酸钠组成高脂饲料,高脂饲料中添加6%的桑椹籽油饲喂Wistar大鼠(桑籽油组)4周后与单饲高脂饲料的大鼠(高脂组)对比血脂和肝脂水平.结果与高脂组比较,桑籽油组大鼠血清和肝脏的胆固醇、甘油三酯含量均显著降低(P＜0.01),血清低密度脂蛋白胆固醇和致动脉硬化指数也明显下降(P＜0.01),而高密度脂蛋白胆固醇和抗动脉硬化指数显著升高(P＜0.01);结论桑椹籽油具有显著的降脂、抗动脉粥样硬化作用.     

The methionine precursor dl-2-hydroxy-(4-methylthio)butanoic acid protects intestinal epithelial barrier function

dl-2-hydroxy-(4-methylthio)butanoic acid (HMTBA) is a source of dietary methionine (Met) that is widely used in poultry nutrition. We have previously shown that HMTBA is preferentially diverted to the transsulfuration pathway, which gives antioxidant metabolites such as taurine and glutathione. Therefore, here we hypothesize that this Met source can protect epithelial barrier function in an in vitro model of intestinal inflammation of Caco-2 cells. The results show that HMTBA prevents the increase in paracellular permeability induced by H₂O₂ or tumour necrosis factor-α. This effect can be attributed to the increased production of taurine and reduced glutathione. Similar results were obtained for dl-Met, although the protective role of the amino acid was less pronounced than that of the hydroxy analogue. In conclusion, the diversion to the transsulfuration pathway means that this Met precursor is of greater value than previously thought, due to its capacity to improve intestinal homeostasis and the quality of poultry products destined for human consumption.     

灵芝片抗疲劳作用实验研究

目的研究林中宝灵芝片抗疲劳的作用。方法按小鼠体重分为高、中、低剂量组。分别灌胃给予1.03、0.36、0.18g/kg的灵芝片30d,对照组给予生理盐水。通过小鼠负重游泳实验测定小鼠耐缺氧时间、小鼠肝糖原含量改变及小鼠血清尿素氮含量变化等。观察小鼠运动性疲劳时林中宝灵芝片对体内相关指标的影响及其机制。结果林中宝灵芝片组小鼠游泳时间、耐缺氧力、肝糖原含量、血清尿素氮含量降低均与生理盐水组有显著差异。结论林中宝灵芝片有明显的抗疲劳作用。     

聚乙二醇与蛋白质相互作用的荧光和共振散射光谱研究

用荧光光谱和共振散射光谱(RLS)研究了聚乙二醇(PEG)与牛血清白蛋白(BSA)在溶液中的相互作用.通过考察PEG浓度对体系荧光光谱和RLS光谱的变化规律,探讨了两者之间的相互作用机理.结果表明PEG与BSA之间的相互作用较弱,对BSA的结构和构象影响较小.然而,铜离子的加入可以有效的促进PEG与BSA之间的相互作用,不仅引起体系荧光有规律的猝灭,而且使得体系共振散射光谱出现持续的增强.     

锌酞菁的微波合成及牛白蛋白测定研究

以邻苯二腈、硫酸锌为原料,采用微波固相法合成了锌酞菁。将锌酞菁磺化所得的磺酸基锌酞菁溶液与牛白蛋白作用将导致共振瑞利散射显著增强。在470nm处存在一共振散射强峰,牛白蛋白在0.25～20μg/mL的浓度范围内与散射强度（ΔI）呈线性关系,磺酸基锌酞菁溶液对牛白蛋白的检测限为0.17μg/mL,并且方法有较好的选择性。由此建立一种用共振散射光谱测定牛白蛋白的简便、快速的新方法。     

聚醚砜微孔膜对牛血清蛋白吸附性能的研究

主要研究了聚醚砜(PES)微孔膜对牛血清蛋白(BSA)的吸附性能.用BCA(bicinchoninincacid)法测定了膜孔中吸附的蛋白量.运用扫描电子显微镜和电子单纱强力仪分别对PES膜结构和力学性能进行表征.随着聚乙二醇20000(PEG20000)与聚乙二醇400(PEG400)比值的增大牛血清蛋白的吸附量先减小后增大,水通量先增大后减小,截留率始终维持在97.93%～99.39%之间,结果表明,PEG20000与PEG400比例为2时PES膜的亲水性最好,对BSA的吸附量最小.     

Electroseparation of an antibacterial peptide fraction from snow crab by-products hydrolysate by electrodialysis with ultrafiltration membranes

Recently, a snow crab by-products hydrolysate has demonstrated antibacterial properties due to a peptide with a molecular weight of about 800 Da, but only at high concentration. Consequently, peptide hydrolysate has been fractionated to obtain peptides in a more purified form. The aim of this work was to separate a snow crab by-products hydrolysate by electrodialysis with ultrafiltration membranes (EDUF). EDUF, which allows separation of molecules according to their charges and molecular weights, was used to recover and concentrate the active antibacterial fraction. Two different ultrafiltration membranes (20 and 50 kDa) and two electrical field strengths (2 and 14 V/cm) were used as separation parameters. After EDUF separation, the 300-600 Da peptide molecular weight range was the most recovered with an abundance of 94%. Moreover, fractionation at 14 V/cm with ultrafiltration membranes of 50 kDa allowed the recovery of an anionic fraction which showed antibacterial properties on Escherichia coli ATCC 25922 and Listeria innocua HPB 13.     

Proteomics in the Diagnosis of Endometriosis: Opportunities and Challenges

The non‐surgical diagnosis of endometriosis is still challenging for the clinician. Ultrasonography and magnetic resonance imaging can be used to diagnose ovarian endometriotic cysts and deep infiltrating endometriosis; but their performance is poor in the diagnosis of initial stages of endometriosis. CA‐125 and other serum markers (such as CA 19‐9, serum protein PP14, interleukins, and angiogenetic factors) have been measured in women with endometriosis but they are not reliable for the diagnosis of the disease. Although several studies used proteomics technologies to identify plasmatic markers of endometriosis, the non‐invasive diagnosis of endometriosis is far from being achieved. In this issue, Manousopoulou et al. compare the integrated quantitative proteomic profile of eutopic endometrium and serum of women with endometriosis and controls. 1214 proteins are differentially expressed in the eutopic endometrium and 404 proteins in the serum of the two study groups. 21 proteins are aberrantly expressed in both eutopic endometrium and serum of women with endometriosis. More work is needed to assess if the differentially expressed proteins identified in this study can be used as clinical markers of endometriosis.     

Co-products of beef processing enhance non-haem iron absorption in an in vitro digestion/caco-2 cell model

Beef processing produces high volumes of protein rich, low value, ‘waste’ co-products such as offal. Beef improves uptake of low bioavailable non-haem iron (found in vegetables, fortificants, supplements) and this effect is dubbed the ‘meat-factor’, although the underlying mechanism is not fully understood. Here, we investigate whether bovine co-products (kidney, lung, heart) not previously studied share this enhancing potential. This was determined by coupled in vitro digestion of co-products and subsequent caco-2 cell ferritin formation (an intracellular iron storage protein). In this study we show that bovine co-products significantly increase caco-2 cells’ response to non-haem iron from infant rice cereal. The presence of these co-products, (kidney, lung and heart), increased relative uptake (by 207.13%, 171.21%, 265.28%, respectively), to a greater extent than beef (30.23%). Our findings present a novel function for co-products of beef processing that may have potential as food ingredients to improve non-haem iron bioavailability, thus adding value.