Staphylococcus aureus lipoproteins trigger human corneal epithelial innate response through toll-like receptor-2

Bacterial lipoproteins (LP) are a family of cell wall components found in a wide variety of bacteria. In this study, we characterized the response of HUCL, a telomerase-immortalized human corneal epithelial cell (HCEC) line, to LP isolated from Staphylococcus (S) aureus. S. aureus LP (saLP) prepared by Triton X-114 extraction stimulated the activation of NF-kappa B, JNK, and P38 signaling pathways in HUCL cells. The extracts failed to stimulate NF-kappa B activation in HUCL cells after lipoprotein lipase treatment and in cell lines expressing TLR4 or TLR9, but not TLR2, indicating lipoprotein nature of the extracts. saLP induced the up-regulation of a variety of inflammatory cytokines and chemokines (IL-6, IL-8, ICAM-1). antimicrobial molecules (hBD-2, LL-37, and iNOS), and homeostasis genes (Mn-SOD) at both the mRNA level and protein level. Similar inflammatory response to saLP was also observed in primarily cultured HCECs using the production of IL-6 as readout. Moreover, TLR2 neutralizing antibody blocked the saLP-induced secretion of IL-6, IL-8 and hBD2 in HUCL cells. Our findings suggest that saLP activates TLR2 and triggers innate immune response in the cornea to S. aureus infection via production of proinflammatory cytokines and defense molecules. (C) 2007 Elsevier Ltd. All rights reserved.

缘毛鸟足兰的生殖生态学研究

缘毛鸟足兰是在具有近20,000种的兰科中迄今为止报导过的雄性不育类型与两性类型共存的唯一例子。深入研究缘毛鸟足兰中雄性不育类型和两性类型共存的现象有助于丰富对兰科生殖系统演化的理解。本文通过生殖生态学研究，得出如下结论。 1. 证实了缘毛鸟足兰中只存在两性类型和雄性不育类型。雄性不育类型始终与两性类型出现在同一居群中，没有单独的雄性不育类型居群。雄性不育类型在调查的16个居群中，在6个居群中出现，约占38%。两种类型共存的居群中雄性不育类型的比率变化很大，从1%到78%，但只在一个居群中超过50%。 2. 通过交配系统实验发现，共存于同一居群中的短距雌性类型和两性类型都存在无融合生殖方式，种子的形成无需授粉。本文第一次报导了在兰科中存在同一无融合生殖种中两性类型和雄性不育类型共存于同一居群的现象。 3. 缘毛鸟足兰花部结构变异很大，结合性别和花的形态特征，将缘毛鸟足兰划分为6类生物型，分别是小花两性、大花两性、短距两性、短距雌性、长距雌性和三瓣雌性。 4. 在同一居群中短距雌性型和小花两性型在生殖和生态上存在差异：1)短距雌性型更能耐受不利的环境条件;2) 短距雌性型的花期早于两性型;3) 短距雌性型平均单株结实较多，但从平均单株产生的胚总数上看，两种类型之间却没有显著差异;4)在资源分配策略上，两种类型各有利弊。

Molecular cloning, promoter analysis and induced expression of the complement component C9 gene in the grass carp Ctenopharyngodon idella

Complement-mediated killing of pathogens through lytic pathway is an important effector mechanism of innate immune response. C9 is the ninth member of complement components, creating the membrane attack complex (MAC). In the present study, a putative cDNA sequence encoding the 650 amino acids of C9 and its genomic organization were identified in grass carp Ctenopharyngodon idella. The deduced amino acid sequence of grass carp C9 (gcC9) showed 48% and 38.5% identity to Japanese flounder and human C9, respectively. Domain search revealed that gcC9 contains a LDL receptor domain, an EGF precursor domain, a MACPF domain and two TSP domain located in the N-terminal and C-terminal, respectively. Phylogenetic analysis demonstrated that gcC9 is clustered in a same clade with Japanese flounder, pufferfish and rainbow trout C9. The gcC9 gene consists of 11 exons with 10 introns, spacing over approximately 7 kb of genomic sequence. Analysis of gcC9 promoter region revealed the presence of a TATA box and some putative transcription factor such as C/EBP, HSF, NF-AT, CHOP-C, HNF-3B, GATA-2, IK-2, EVI- 1, AP-1, CP2 and OCT-1 binding sites. The first intron region contains C/EBPb, HFH-1 and Oct-1 binding sites. RT-PCR and Western blotting analysis demonstrated that the mRNA and protein of gcC9 gene have similar expression patterns, being constitutively expressed in all organs examined of healthy fish, with the highest level in hepatopancreas. By real-time quantitative RT-PCR analysis, gcC9 transcripts were significantly up-regulated in head kidney, spleen, hepatopancreas and down-regulated in intestine from inactivated fish bacterial pathogen Flavobacterium columnare-stimulated fish, demonstrating the role of C9 in immune response. (c) 2007 Elsevier B.V. All rights reserved.

InP 基HEMT 材料与器件研究

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

四川和云南汉族长寿老人长寿机理研究

随着社会的发展，人均寿命的延长，人口老龄化已经成为我国不可回避的社会 问题。老年人在医疗卫生保健方面的花费远远超过普通人群。健康长寿老人能避 免或者延缓年龄相关疾病的发生，从而减少在卫生保健方面的花费；另外，长寿 老人的子女在年龄相关疾病方面的患病率也显著低于年龄相匹配的对照组。因 此，开展健康长寿方面的研究，一方面可以提高老年人的生活质量，另一方面可 以改善由于人口老龄化而引起的社会问题。 我国长寿老人大多零散分布在乡区，并且由于长寿老人的身体条件等原因， 给完整的收集相关数据带来困难。国内关于长寿的研究主要集中在城镇，而且由 于人群、地域、生活方式等差异我们也不能完全借鉴国外的研究成果。因此,我 们对四川和云南汉族健康长寿老人进行横断面研究,并对其长寿机理进行探索。 从亲缘关系上我们把样品分为：长寿组、血缘组和无血缘组三个组；从年龄上分 为：≤59、60-89、90-94 和≥95 四个组。在实验中，我们测定了常规体检指标， 常见促炎细胞因子和抗炎细胞因子水平以及其调控区的单核苷酸多态性。 一般认为随着年龄增加血糖水平升高，并且高水平的 HDL-C 和高比率的 HDL-C/TC 以及低TC,TG 和LDL-C 水平有利于长寿。都江堰长寿老人血糖水平偏 低，显著低于血缘组和无血缘组以及其他年龄组；调整年龄后，都江堰≥95 岁 年龄组的血糖水平显著高于90-94 年龄组；血糖水平在性别间不存在显著差异。 都江堰长寿老人LDL-C 水平在90-94 和≥95 年龄组显著低于其他年龄组，≥95 年龄组显著低于90-94 年龄组；调整性别后，90-94 年龄组女性的LDL-C 水平显 著高于男性水平，其他年龄组在性别间差异不显著；女性≥95 年龄组显著低于 90-94 年龄组，但在男性中差异不显著。TG 和TC 水平在都江堰和红塔两地各组 中的变化趋势都存在着差异，在性别间比较发现两地各年龄组变化趋势都一致， 仅在90-94 年龄组女性都显著高于男性。HDL-C 水平和HDL-C/TC 在都江堰和红 塔两地各组中变化趋势不一致，调整性别后HDL-C/TC 在90-94 年龄组两地女性 的比率都显著大于男性。通常IL6、IL10 和TNFα 水平随着年龄增加而升高。云 南长寿老人的IL6 水平显著高于血缘组和无血缘组，性别之间的差异不显著。 IL10 水平长寿组显著高于无血缘组，TNFα 水平在各组间差异不显著，由于这两 种细胞因子在绝大多数个体中呈本底水平表达，很难分析年龄与它们水平的相关性。在这三种细胞因子调控区的常见SNPs 位点上，许多研究表明il10-1082 和 il6-174 位点和长寿存在着一定的相关性，tnfα-308 位点与长寿不存在相关性。 在我们收集的样品中il6-174 位点不存在多态性。男性个体的il10-592A 和-819T 的等位基因频率在长寿组显著高于无血缘组，在-1082 位点与长寿不存在相关性。 tnfα-238A 和-308A 等位基因频率在长寿组中显著高于无血缘组，在各组单倍型 间的差异显著，G-G 单倍型在长寿组中呈下降趋势；调整性别后，两位点的等位 基因频率在各组间的差异不显著，但单倍型在各组间差异显著，变化趋势同调整 性别前一致。 总之，四川都江堰长寿人群的血糖水平和LDL-C 水平比较低，都江堰和云南 红塔两地长寿老人的血脂水平存在着地域差异。与前人的研究结果比较,汉族人 群的IL6、IL10 和TNFα水平以及常见的启动区SNPs 位点可能存在人种差异。

调节LDLR及VCAM-1基因表达的微生物代谢产物的研究

为了筛选对靶基因LDLR和VCAM-1的表达具有调节作用的生物活性物质，建立了两个基于重组人细胞系的高通量的筛选模型，使用荧光素酶在96-孔版上来筛选对上述靶基因的表达具有调节作用的微生物代谢产物。模型之一是来自于人肝HepG2细胞系的重组L39细胞，用于筛选增加LDLR报告基因表达的生物活性物质，以期发现新的具有降胆固醇作用的药物。筛选之二为来源于细胞系ECV304的重组细胞株Nl-14,用于筛选抑制VCAM-1基因表达的活性物质，以期发现治疗风湿性关节炎等免疫性疾病治疗的药物。上述筛选系统均是稳定转染的细胞系，分别含有与荧光素酶报告基因相融合的LDLR或VCAM-1基因的转录调节元件。通过对6300株微生物的总计12600个样品的筛选，共发现和分离了17个活性化合物并进行了结构解析。其中两个被命名为Cladospolede D和Zelkovamycin的化合物被确定为新的化合物。由真菌 FO-6605的发酵液提取得到的一个化合物对LDLR报告基因的表达具有很强的上调作用，其SC200为1 Onmol/L a使用荧光标记的LDL检测到该化合物对于HepG2细胞膜上LDLR具有剂量依赖的增强作用。由真菌FO-5897的发酵液中分离到了一个已知的化合物Ascofuranone，该化合物曾经被报道具有降血脂抗肿瘤的活性。值得注意的是我们首次发现了该化合物同时具有抑制 VCAM-1报告基因表达和增强LDLR报告基因表达的作用，该发现有可能会对其降血脂作用的深入研究提供帮助。由海洋真菌FT-0012产生的化合物Cladospolede D为一个12-员环的大环内酷类的化合物，该化合物对两个测活系统均显示出无选择性的抑制作用形态学研究显示该真菌属于Cladosporiun属。另外一个由土壤放线菌K96-670产生的新化合物为一个环八肤类的化合物，经~1H~1-H COSY,~(13)C-H COSY,~(13)C-~1H HMQC, ~(15)N-~1H HMQC,~(15)-~1N HHMBC等波谱学研究得知该化合物的分子结构中含有六个非普通的氨基酸和两个普通氨基酸。该化合物对VCAM-I报告基因的表达显示出非常好的选择性的抑制活性，其IC50值为9.5ug/ml.形态学的研究表明该菌株属于链霉菌属。 在筛选过程中从来源于云南省西双版纳的土壤中分离到了一株编号为YIM1272的放线菌，经包括形态学、生理一生化和16S rDNA在内的分类学研究，确定该菌株为链霉菌属的一个新种，被命名为佩版纳链霉菌，(Streptomyces.bannaensis．sp.nov）。

Early effects of low dose C-12(6+) ion or X-ray irradiation on human peripheral blood lymphocytes

The aim of this study was to estimate the acute effects of low dose C-12(6+) ions or X-ray radiation on human immune function. The human peripheral blood lymphocytes (HPBL) of seven healthy donors were exposed to 0.05 Gy C-12(6+) ions or X-ray radiation and cell responses were measured at 24 h after exposure. The cytotoxic activities of HPBL were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT); the percentages of T and NK cells subsets were detected by flow cytometry; mRNA expression of interleukin (IL)-2, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma were examined by real time quantitative RT-PCR (qRT-PCR); and these cytokines protein levels in supematant of cultured cells were assayed by enzyme-linked immunosorbent assays (ELISA). The results showed that the cytotoxic activity of HPBL, mRNA expression of IL-2, IFN-gamma and TNF-alpha in HPBL and their protein levels in supernatant were significantly increased at 24 h after exposure to 0.05 Gy C-12(6+) ions radiation and the effects were stronger than observed for X-ray exposure. However, there was no significant change in the percentage of T and NK cells subsets of HPBL. These results suggested that 0.05 Gy high linear energy transfer (LET) C-12(6+) radiation was a more effective approach to host immune enhancement than that of low LET X-ray. We conclude that cytokines production might be used as sensitive indicators of acute response to LDL (C) 2009 COSPAR. Published by Elsevier Ltd. All rights reserved.

孔石莼多糖及其衍生物的研究

在中国，孔石莼应用于医药方面已有几千年的历史，其煎剂常被当地居民用来治疗中暑和泌尿方面的疾病。实验室以前所做的工作表明，孔石莼的水溶多糖具有很好的抗高血脂活性，本论文在此研究的基础上主要就多糖的长期毒性、一般药理、多糖的衍生化、不同分子量孔石莼多糖的抗氧化活性、衍生物的抗氧化活性和动物调血脂活性进行了研究。 水提醇沉制备多糖，多糖主要由糖醛酸、鼠李糖、木糖、葡萄糖和硫酸根组成，还含有微量的半乳糖、甘露糖和阿拉伯糖。多糖中主要的二糖重复单位为[β-D-Glcp A-(1->4)- α-L-Rhap 3S] 和 [α-L-Idop A-(1->4)- α-L-Rhap 3S]。急性毒性实验表明，KM小鼠对孔石莼多糖的最大耐受量(MTD)大于4000 mg/kg，其腹腔注射雌性小鼠的半致死量(LD50)为408.7 mg/kg，雄性动物为432.7 mg/kg。长期毒性（6个月）实验表明孔石莼多糖无毒反应剂量为1.2 g/kg。一般药理研究表明孔石莼多糖对小鼠中枢神经系统无明显影响，对麻醉犬心血管系统和呼吸系统均无明显影响。 采用过氧化氢降解的方法制备了不同分子量的孔石莼多糖，并且测定了体外抗氧化活性；制备了高硫酸根含量的孔石莼多糖、乙酰化和苯甲酰化孔石莼多糖衍生物，测定了体外抗氧化活性和动物调血脂试验。结果表明，不同分子量的孔石莼多糖其抗氧化活性是不同的，分子量低的孔石莼多糖表现出了较强的抗氧化活性。孔石莼多糖的衍生物其抗氧化活性要优于孔石莼多糖。调血脂动物试验表明，孔石莼多糖以及其衍生物都具有很好的调血脂效果。高硫酸根含量孔石莼多糖的中、低剂量组的调血脂活性要优于高剂量组（低剂量组降低低密度脂蛋白的能力要稍弱于原料），而且，中剂量组与原料组相比，小鼠血清TG明显降低（P＜0.05），LDL－C 明显降低（P＜0.01）。低剂量组乙酰化衍生物降低甘油三酯（TG）和低密度脂蛋白（LDL－C）的能力要优于中高剂量组。对于孔石莼多糖以及衍生物调血脂的机制还需进一步的研究。

Antihyperlipidemic effects of different molecular weight sulfated polysaccharides from Ulva pertusa (Chlorophyta)

Ulvan, a sulfated polysaccharide from Ulva pertusa, was degraded to yield two low molecular weight fractions U1 and U2. The molecular weights of ulvan and its fractions were determined and varied from 151.6 to 28.2 kDa. They were fed to rats on a hypercholesterolemic diet for 21 days to evaluate and compare the antihyperlipidemic actions. Ulvan-based diet significantly lowered the levels of serum total cholesterol (-45.2%, P < 0.05) and low density lipoprotein cholesterol (LDL-cholesterol, -54.1%, P < 0.05). While U1- and U2-based diets significantly elevated the levels of serum high density lipoprotein cholesterol (HDL-cholesterol, +22.0% for U1, not significant; +61.0% for U2; P < 0.05) and reduced triglyceride (TG, -82.4% for U1, -77.7% for U2; P < 0.05) in rats as compared to control diet. In addition, consumptions of various ulvans significantly increased fecal bile acid excrement. The results indicated that ulvans with different molecular weights exhibited diverse effects on lipid metabolism. The high molecular weight ulvan was effective in serum total and LDL-cholesterol, whereas low molecular weight fractions were in TG and HDL-cholesterol. The fractions were considered to be more beneficial to hyperlipidemia associated with diabetes over ulvan. (C) 2003 Elsevier Ltd. All rights reserved.

Necessity of dietary lecithin and eicosapentaenoic acid for growth, survival, stress resistance and lipoprotein formation in gilthead sea bream Sparus aurata

The substitution of dietary docosahexaenoic acid (DHA) with eicosapentaenoic acid (EPA) reduces larval growth in gilthead sea bream. However, the value of EPA when dietary DHA is able to meet the requirements of the larvae has not been sufficiently studied. Dietary phosphoacylgliceride levels also affect fish growth and it has been suggested that they enhance lipid transport in developing larvae. The present experiment was carried out to further study the effect of dietary lecithin and eicosapentaenoic acid on growth, survival, stress resistance,. larval fatty acid composition and lipid transport, when DHA is present in the microdiets of gilthead:sea bream. Eighteen thousand gilt-head sea bream larvae of 4.99+/-0.53 mm total length were fed three microdiets tested by triplicate: a control diet [2% soybean lecithin (SBL) and 2.89% EPA], a low EPA diet,(2% SBL and 1.63% EPA) and a no SBL diet (0% SBL and 2.71% EPA). Handling, temperature and salinity tests determined larval resistance to stress. The results show that when dietary DHA levels are high, but dietary arachidonic acid (ARA) levels are about 0.2%, EPA is necessary to improve larval growth, and survival. Larval EPA content, but not DHA or ARA, was affected by dietary EPA levels. Increased dietary EPA improved larval stress resistance to handling and temperature tests, which could be related to its possible role as a regulator of cortisol production whereas it did not affect stress resistance after salinity shock. Larvae fed the no SBL diet showed a lower lipid content characterized by a low proportion of saturated and monounsaturated fatty acids, together with a significant reduction in the appearance of lipoprotein particles in the lamina propria and in the size of such particles, denoting a critical reduction in dietary lipid transport and utilization, and lower larval growth and survival rates.

柴达木盆地唐古特白刺籽油的安全性与降血脂作用

对柴达木唐古特白刺种籽油的安全性和降血脂作用进行了研究。以超临界CO2萃取技术提取白刺种籽油，采用小白鼠进行急性毒性实验和安全性评价，以高脂例料诱导建立大鼠高脂动物模型，灌胃种籽油4w，测定动物血清血脂水平。结果表明，小鼠每日给予白刺籽油40ml／kg，连续观察14d，无毒性表现，服用安全；种籽油5g／kg和10g／kg剂量对高脂饲料诱导的大鼠血清TC、TG及LDL具有显著的抑制作用，可显著升高高血脂大鼠HDL／TC和HDL／LDL的比值，表明高剂量白刺种籽油具有显著的降血脂作用。

柴达木盆地唐古特白刺果实降血脂和抗氧化作用研究

为了研究柴达木盆地唐古特白刺果实的降血脂、抗氧化作用，本文采用高脂饲料诱导小鼠和大鼠 建立高脂动物模型，灌胃给药4周，测定各组实验动物的血清血脂水平，并测定大鼠红细胞SOD活性和血清脂质过氧化物（LPO）分解产物丙二醛（MDA）的含量变化。结果显示唐古特白刺果实1.8g/kg和3.6g/kg剂量对高脂饲料诱导的小鼠和大鼠血清TC、TG及大鼠的LDL具有显著的抑制作用；同时可显著升高高血脂大鼠HDL/TC和HDL/LDL的比值，提高高血脂大鼠SOD活力和降低高血脂大鼠MDA含量；对大鼠体重和正常小鼠血脂水平无明显影响。表明唐古特白刺果实具有降血脂、防治动脉粥样硬化和抗氧化作用。