山茱萸多糖对衰老大鼠晶状体中Sirt1基因表达的影响

目的：初步探讨山茱萸多糖治疗年龄相关性白内障的可能机制，为其预防和治疗寻找新的药物和靶点。方法：选用60只昆明大鼠，按体质量随机分为3组，每组20只，分别为对照组（C组）、衰老模型组（A组）和山茱萸多糖给药组（D组）。在相同环境下，C组正常饮食，每日颈背部皮下注射0．9％氯化钠注射液，剂量计算参照其他给药组D-半乳糖给药量；A和D组正常饮食，每日颈背部皮下注射D-半乳糖100mg／（kg·d）；连续皮下注射45d后，C和A组每日按照等剂量灌药量灌服温开水；D组按照多糖0．4g／蛞灌服山莱萸多糖，连续灌服30d。试验终期颈椎离断术处死大鼠，4℃迅速取眼分离晶状体置于液氮备用。免疫组化方法检测各组间总超氧化物歧化酶（T-SOD）和总抗氧化能力（T-AOC）的变化，RT—PCR（逆转录cDNA的聚合酶链式扩增反应）检测各组Sirt1、p53和FOXO1 mRNA的表达变化。结果：A组和D组大鼠晶状体中Sirt1 mRNA的表达较C组均显著上升（P〈0．05、P〈0．01），且D组较A组显著上升（P〈0．01）；A组和D组大鼠晶状体中p53 mRNA的表达较C组显著上升（P均〈0．01），而D组较A组显著下降（P〈0．05）；A组和D组大鼠晶状体中FOXO1 mRNA的表达较C组显著上升（P〈0．05、P〈0．01），且D组较A组显著上升（P〈0．01）。另外A组和D组大鼠晶状体中T—SOD的活性较C组显著上升（P均〈0．01），且D组较A组显著上升（P〈0．01）；A纽和D组大晶状体中鼠T-AOC的活性较C组显著上升（P均〈0．01），且D较A组显著上升（P〈0．01）。结论：山茱萸多糖可能通过调节Sirt1的表达，从而调节下游基因p53和FOXO1的表达，最终抑制或延缓晶状体上皮细胞的凋亡，减缓年龄相关性白内障的进展。     

A Study on the Extraction and Purification Process of Lily Polysaccharide and Its Anti-Tumor Effect

The objective of this paper was to extract and purify lily polysaccharide and to study its anti-H22 hepatoma effect in mice. Orthogonal experimental method was used to analyze the factors influencing the extraction and purification of lily polysaccharide, and the anti-tumor effect of lily polysaccharide was studied by acting it on H22-bearing mice. The results showed that the size of influence of various factors on the extraction results of lily polysaccharide were extraction time, extraction times and extraction temperature in decreasing order. Lily polysaccharide can enhance the immune function of H22 tumor-bearing mice, and inhibit the growth of H22 tumor. The study concluded that the optimal conditions for the extraction and purification of lily polysaccharide should be extraction times of 3 times, an extraction time of 4 h each, and an extraction temperature of 60°C; lily polysaccharide has an anti-tumor effect.     

Short Communication Effect of sulfated polysaccharides on hepatocyte adhesion

The effects of sulfated polysaccharides on hepatocyte adhesion on the polystyrene dish and fibronectin-coated dish were investigated. Dextran sulfate and synthetic mannopyranan sulfate slightly inhibited hepatocyte adhesion on fibronectin-coated dish, while heparin showed no effect. On the other hand, hepatocyte adhesion on polystyrene dishes was stimulated in the presence of sulfated polysaccharides in the medium.     

A new tool to test active ingredient using lactic acid in vitro,a help to understand cellular mechanism involved in stinging test: An example using a bacterial polysaccharide (Fucogel®)

The stinging test is an in vivo protocol that evaluates sensitive skin using lactic acid (LA). A soothing sensation of cosmetics or ingredients can be also appreciated through a decrease in stinging score. To predict the soothing sensation of a product before in vivo testing, we developed a model based on an LA test and substance P (SP) release using a co‐culture of human keratinocytes and NGF‐differentiated PC12 cells. A bacterial fucose‐rich polysaccharide present in Fucogel^® was evaluated as the soothing molecule in the in vivo stinging test and our in vitro model. Excluding toxic concentrations, the release of SP was significant from 0.2% of lactic acid for the PC12 cells and from 0.1% of lactic acid for the keratinocytes. When the pH was adjusted to approximately 7.4, LA did not provoke SP release. At these concentrations of LA, 0.1% of polysaccharide showed a significant decrease in SP release from the two cellular types and in co‐cultures without modifying the pH of the medium. In vivo, a stinging test using the polysaccharide showed a 30% decrease in prickling intensity vs the placebo in 19 women between the ages of 21 and 69. Our in vitro model is ethically interesting and is adapted for cosmetic ingredients screening because it does not use animal experimentation and limits human volunteers. Moreover, Fucogel^® reduced prickling sensation as revealed by the in vivo stinging test and inhibits the neurogenic inflammation as showed by our new in vitro stinging test based on SP release.     

Translating vaccine policy into action: A report from the Bill & Melinda Gates Foundation Consultation on the prevention of maternal and early infant influenza in resource-limited settings

Immunization of pregnant women against influenza is a promising strategy to protect the mother, fetus, and young infant from influenza-related diseases. The burden of influenza during pregnancy, the vaccine immunogenicity during this period, and the robust influenza vaccine safety database underpin recommendations that all pregnant women receive the vaccine to decrease complications of influenza disease during their pregnancies. Recent data also support maternal immunization for the additional purpose of preventing disease in the infant during the first six months of life.     

A＋C群脑膜炎球菌多糖结合疫苗上市后安全性研究

目的对A＋C群脑膜炎球菌多糖结合疫苗（Group A and C Meningococcal Polysaccharide Conjugate Vaccine，MPCV．AC）进行上市后安全性评价，为在人群中应用提供参考。方法2011年10月～2012年9月，在广州市采用分层随机抽样方法抽取5月龄～5岁受种儿童，连续随访3天，主动监测不良反应发生情况。采用整群随机抽样方法，对受种儿童进行被动监测，观察接种后MPCV．AC不良反应发生情况。结果主动监测262名受种儿童，5N23月龄婴幼儿（60人）未观察到不良反应，2～5岁儿童7人（3．4653％，7/202）出现轻度局部不良反应。10356名被动监测儿童接种MPCV-AC后，19例（0．1835％）报告轻度局部反应（主要为硬结和红、肿），9人（0．0869％）出现全身反应。结论儿童接种MPCV-AC有良好的安全性。     

Study of a cross-linked hydrogel of Karaya gum and Starch as a controlled drug delivery system

Abstract

A cross-linked hydrogel was synthesized using a hybrid backbone of karaya gum starch and grafted with polyacrylic acid. It showed a maximum swelling ratio (SR) of 30.5?g/g at pH 10 and was explored as an oral drug delivery carrier using paracetamol and aspirin as model drugs. In vitro release experiments revealed that maximum drug release at pH 7.4 in comparison to pH 1.2 (simulated intestinal vs gastric fluid) and neutral medium. The release profiles of these drugs showed no initial burst. It also showed good hemocompatibilty and non-cytotoxicity for its employment as a site specific drug delivery agent.     

Vi capsular polysaccharide: Synthesis,virulence, and application

Vi capsular polysaccharide, a linear homopolymer of α-1,4-linked N-acetylgalactosaminuronate, is characteristically produced by Salmonella enterica serovar Typhi. The Vi capsule covers the surface of the producing bacteria and serves as an virulence factor via inhibition of complement-mediated killing and promoting resistance against phagocytosis. Furthermore, Vi also represents a predominant protective antigen and plays a key role in the development of vaccines against typhoid fever. Herein, we reviewed the latest advances associated with the Vi polysaccharide, from its synthesis and transport within bacterial cells, mechanisms involved in virulence, immunological characteristics, and applications in vaccine, as well as its purification and detection methods.     

A tethering mechanism for length control in a processive carbohydrate polymerization

Carbohydrate polymers are the most abundant organic substances on earth. Their degrees of polymerization range from tens to thousands of units, yet polymerases generate the relevant lengths without the aid of a template. To gain insight into template-independent length control, we investigated how the mycobacterial galactofuranosyltransferase GlfT2 mediates formation of the galactan, a polymer of galactofuranose residues that is an integral part of the cell wall. We show that isolated recombinant GlfT2 can catalyze the synthesis of polymers with degrees of polymerization that are commensurate with values observed in mycobacteria, indicating that length control by GlfT2 is intrinsic. Investigations using synthetic substrates reveal that GlfT2 is processive. The data indicate that GlfT2 controls length by using a substrate tether, which is distal from the site of elongation. The strength of interaction of that tether with the polymerase influences the length of the resultant polymer. Thus, our data identify a mechanism for length control by a template-independent polymerase.     

卡介菌多糖核酸干预豚鼠急性过敏反应的研究

目的:研究卡介菌多糖核酸对豚鼠急性过敏反应的作用及可能的机制,探讨卡介菌多糖核酸的质量控制效力模型的提高方法。方法:建立牛血清白蛋白诱导豚鼠产生急性过敏反应模型。激发后30 min内观察豚鼠全身反应,并根据致敏性症状评分标准分级。取血用ELISA法测致敏前、攻击前及攻击后豚鼠血清总Ig E和组胺水平。结果:攻击后,模型组和卡介菌多糖核酸低剂量组豚鼠出现不同程度的急性过敏反应症状,而卡介菌中、高剂量组豚鼠急性过敏反应症状明显缓解。模型组在攻击前、后采集的血清总Ig E水平分别为1.637 0±0.158 6,1.683 1±0.228 1μg·ml-1,较正常对照组显著升高(P<0.01),而同时给予卡介菌多糖核酸后,卡介菌高剂量和中剂量处理组在攻击前、后采集的血清总Ig E水平与模型组比较均显著降低(P<0.01)。经牛血清蛋白致敏后,在攻击前后,模型组血清中组胺水平分别为1.499 7±0.133 1,1.512 1±0.050 6μg·ml-1,与阴性对照组相比均显著升高(P<0.01),而同时给予卡介菌多糖核酸后,卡介菌高、中、低各剂量处理组在攻击前、后采集的血清中组胺水平与模型组比较有明显降低(P<0.01)。结论:卡介菌多糖核酸可剂量依赖性抑制牛血清蛋白引起的急性过敏反应。其抗急性过敏反应的可能机制与降低血清总Ig E和组胺水平有关。