外质体H_2O_2和木质素积累在镍诱导的水稻对白叶枯病系统抗性中的作用

【目的】植物外质体是病原入侵的结构和生理性屏障。本文研究外质体反应在镍诱导的、对白叶枯病系统抗性中的作用,以探讨植物对病原和重金属交叉抗性的生理机制。【方法】以0.5、1.0和2.0mmol·L-1硝酸镍喷施三叶期水稻幼苗的第二叶及以下部位,3d后在未处理的第三叶接种稻白叶枯菌(Xanthomonas oryzae pv.oryzae,Xoo),接种后12d调查病情。测定了2.0mmol·L-1镍处理或/和Xoo接种的幼苗第三叶外质体中愈创木酚POD(G-POD)、NADH-POD、二胺氧化酶(DAO)活性、H2O2和木质素含量。【结果】镍诱导了幼苗对白叶枯病的系统抗性,其中2.0mmol·L-1镍的诱导效果最佳。镍处理下,第三叶外质体液(AWF)中和细胞壁结合的G-POD、NADH-POD,以及AWF中DAO的活性和H2O2水平快速上升,木质素含量显著提高;镍诱导且接种组中,上述指标均明显高于未诱导但接种组。另外,产生H2O2的POD的抑制剂NaN3降低了镍诱导的H2O2积累水平和对白叶枯病的系统诱抗效应,而NADPH氧化酶抑制剂(diphenyleneiodonium chloride)预处理则无明显影响。【结论】本研究结果提示,NADH-POD和DAO活性上升是镍诱导外质体H2O2产生的原因;外质体H2O2和木质素在细胞壁中的积累可能参与了镍诱导的水稻对白叶枯病系统抗性的建立。

抗原呈递细胞外质体的研究进展

抗原呈递细胞(APC)在胞吐过程中,向细胞外分泌一种称为exosome的膜性小泡,含有丰富的MHC 分子和共刺激分子等,可以作为MIHC-肽复合物的运输工具,在细胞间传递抗原信息。经肿瘤抗原冲击树突细胞所 释放的外质体能直接或间接地刺激T细胞,从而产生强大的抗肿瘤免疫应答,有望成为新的非细胞免疫治疗载体。

外质体及其源性微RNA的研究进展

外质体（exosomes）因携带有蛋白质、RNA及信号分子，能够在细胞间穿梭，具有生物标记物、信号传导及靶向治疗载体等作用。微RNA （microRNA ，miRNA ）为一类由内源基因编码的长度为20～22个核苷酸的非编码单链 RN A 分子，通过与靶基因3′端非编码区结合从而促进靶基因降解或者抑制其翻译。目前，对exosomes中的miRNA的研究表明，其能影响很多靶细胞功能，鉴定正常人群血液中exosomes的miRNA ，可为人类疾病提供具有预测性的miRNA ，也可探究出特定的miRNA所调节的生物学功能［1］，Koh 等［2］发现 miRNA 也存在于人类胚胎来源的间充质干细胞外环境中，在人类胚胎来源的间充质干细胞的细胞内与细胞外环境中检测到的 miRNA有明显的不同，且let-7 miRNA家族在人类胚胎来源的间充质干细胞的细胞外与细胞内都高表达。先进的 miRNA 检测技术在exosomes中的miRNA检测取得了重要的进步，对其研究也逐渐便利。exosomes中包含了一系列的miRNA ，但是与供体细胞相比，很少核糖体 RNA被检测到［3］。然而，在某些exosomes中的miRNA并没有反映出母细胞中的miRNA谱。在T细胞、B 细胞、树突装细胞中分离出的 exosomes 所含miRNA谱有别于母细胞［4］。相比于细胞内的RNA ，exosomes中的RN A更为稳定，而且在储存及冰冻环境中具有更好地抵抗降解的优势。exosomes膜结构增强了内容物的稳定性，提高了其作为一种癌或疾病的生物标志物的研究潜能。

外质体(Exosomes)与肾脏疾病

外质体(Exosomes)是起源于多泡体的微小囊泡,由细胞内吞途径中的多泡体外膜和细胞膜融合后释放到胞外环境或体液中。Exosomes含有多种蛋白、mRNAs、microRNAs、信号分子等,能够反映来源细胞的生物学状态,因而可能成为潜在的生物学标志物。目前,exosomes的研究大多集中在免疫学和肿瘤学,并已经成为一种免疫治疗的新手段,应用于肿瘤治疗和免疫耐受等方面。近年人们才关注exosomes与肾脏疾病的关系,研究表明几乎所有肾脏上皮细胞包括肾小球足细胞、肾小管上皮细胞、尿道上皮细胞均可分泌exosomes,因此尿液来源的exosomes可能成为寻找肾脏疾病早期诊断的标志物。本文着重从exosomes的生物学特性及其在肾脏疾病诊断和治疗的研究进行综述。

类紫杉醇脂质体体外释放的桨膜结合分析法研究

体外释放度是评价脂质体制剂质量的重要指标,目前各国药典中均未收载脂质体体外释放度评价方法,致使脂质体质量评价缺乏统一标准和无法提供安全性保障。本研究以自制类紫杉醇脂质体为例,通过优化外部释放条件建立的桨膜结合法模拟了在生理条件下类紫杉醇药物12 h的释放情况,结果表明以0.5%SDS-HEPES作为释放介质,采用截留分子量为1000 kD的透析袋对脂质体水溶液进行释放的结果满足要求,且具有区分能力,为载药脂质体体外释放方法开发提供参考。

Skin care efficacy study of recombinant humanized collagen based on in vitro level

Studying the skin care efficacy of recombinant humanized collagen based on in vitro level.The stability of the recombinant humanized collagen was first analyzed by treating at different temperatures,then its skincare efficacy based on in vitro level was evaluated by detecting the inhibition rate of elastase,the inhibition rate of collagenase,the protein content of type I collagen in human fibroblasts,the inhibition of reactive oxygen species(ROS)with human keratinocytes,and the effects of the recombinant humanized collagen on the expression of hyaluronic acid(HA),filaggrin(FLG)and transglutaminase 1(TGM1)in keratinocytes.The results showed that recombinant humanized collagen was able to maintain stability at temperatures below 70℃.With regard to its skincare efficacy,recombinant humanized collagen could inhibit elastase and collagenase activities and promote the increase of type I collagen content in human fibroblasts.It also showed good inhibition of ROS in keratinocytes in vitro and could increase the expression of HA,FLG,and TGM1 in keratinocytes.In short,the recombinant humanized collagen exhibited a favourable skin care effect in vitro level.This study proved that it has potential firming,anti-wrinkle,moisturizing,and repairing efficacy,and is a valuable cosmetic raw material.

植物中的抗坏血酸氧化酶

文章简要介绍植物中抗坏血酸氧化酶的结构、功能、基因的表达调控及其参与的生理反应研究进展。

Protective Effects of Tea Polyphenol on Cerebral Ischemia-Reperfusion Injury in Rats and Its Scavenging Oxy-radical and Anticerebral Lipid Peroxidation Effects

AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cerebral ischemia reperfusion injury was produced by bilateral ligation of the common carotid arteries with vagus nerves and reperfusion for 45 min. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. Superoxide anion (O 2) from xanthine xanthine oxidase system and hydroxyl radical (·OH) from Fe 2+ -H 2O 2 system were determined with spectrophotometry. RESULTS During Cerebral ischemia reperfusion,TP improved the activities of superoxide dismutase ( P 【0 05), GSH peroxidase( P 【0 01) and catalase( P 【0 01), while decreasing the maiondialdchyde content in the brain( P 【0 05) and brain water content ( P 【0 01). Tea polyphenol possessed significantly scavenging effects on ·OH produced by Fenton reaction and O 2 produced by xanthine xanthine oxidase system (the IC 50 were 2 2 mmol·L -1 and 1 9 mmol·L -1 respectively). Tea polyphenol could significant inhibit the lipid peroxidation of cerbral mitochondrial membrane induced by ·OH in a concentration dependent manner. CONCLUSION The results indicate that tea polyphenol could protect the injury on cerebral ischemia reperfusion in rats for OFR, these effects may be related to its scavenging effects on oxygen free radicals and antilipid peroxidant.

Preparation of Liposomes with Palmitic-Antibody andTargeting in Vitro

An anti-trichomonas vaginalis monoclonal antiboody was derivatized with palmitic acid using an activated ester of N-hydroxysuccinimide About 50% of the re-sulting antibody could be incorporated into liposomes.The liposomes showed specific binding to T. vaginalis by IFA and cytotoxicity tests. These results clearly demonstrated the effectiveness of targeting of liposomes modified by monoclonal antibody in vitro.

Improvement of in vitro Cytoplasmic Maturation of Denuded Porcine Oocytes by Coculture with Follicular Mural Granulosa Cells

[Objective] This study aimed to improve the in vitro maturation quality of denuded porcine oocytes and provide scientific basis for establishing a stable and efficient denuded oocyte culture system. [Method] The first polar body extrusion rate, oocyte glutathione （GSH） content, positive rate of brilliant cresyl blue （BCB） staining and development potential of activated oocytes or fertilized oocytes were employed as main indicators to investigate the effects of follicular mural granulosa cell （MGC） coculture on cytoplasmic maturation of cumulus cell-removal oocytes （Denuded Oocyte, DO）. [Result] According to in vitro maturation results, compared with DO group, the first polar body extrusion rate of porcine oocytes in DO＋MGC group was not significantly different, but the nuclear maturation process was improved and was more similar to that in COC （cumulus-oocyte complex） group. Detection of GSH content in mature oocytes showed that there was no significant difference between DO＋ MGC group （optical density of 1 053.67） and COC group （optical density of 1 426.00） or between DO＋MGC group and COC＋GC group （optical density of 1 541.00）, however, GSH content in mature oocytes of DO group （optical density of 724.67） was significantly lower than that of COC group and COC＋GC group （P0.05）. Detection of glucose-6-phosphate dehydrogenase （G6PDH） activity showed that there was no significant difference in BCB positive oocyte rate between DO ＋MGC group （88.26% ） and COC group （92.75%） or between DO＋MGC group and DO group （82.86% ）, however, BCB positive oocyte rate of DO group was significantly lower than that of COC group （P0.05）. Furthermore, the cleavage rate and blastocyst rate of activated mature oocytes derived from DO ＋MGC group （94.98% and 43.67% , respectively） were significantly higher than those from DO group （52.54% and 8.97%, respectively） （P0.05）, and were not significantly different compared with those from COC group （97.11% and 38.30%, respectively）. In addition, the cleavage rate of fertilized oocytes derived from DO＋MGC group （72.65%） showed no significant difference compared with that from DO group （63.59%）, but the blastocyst rate of DO＋MGC group was significantly higher than that of DO group （9.88%） （P0.05）. [Conclusion] MGC coculture can significantly improve the in vitro cytoplasmic maturation quality of denuded porcine oocytes, thereby enhancing the subsequent developmental potential.

Interaction of Soybean Phospholipids Based Lipo-Vesicle and Surfactants of Bile Salts In Vitro

Liposomes were prepared with natural soybean phospholipids by extrusion method after rotating-film evaporating technique. Transmission electron micrography was used to detect the appearances of the prepared liposomes, and the liposome diameter was also measured. The prepared liposomes were sphere in shape with the mean diameter of 217 nm and span of 0.838. The phospholipid bilayer structure, suitable for entrapping various effector molecules, could be seen clearly under transmission electron microscopy. The bile salts of sodium cholate and sodium deoxycholate were used as the surfactants to investigate their interaction with liposomes. The turbidities for the mixture of bile salts and liposomes were evaluated by the visible spectrometry method at the wavelength of 500 nm. And the diameter changes of liposomes were also tested to examine the effect of bile salts on liposomes. At the beginning, the diameters and turbidities of liposomes increased a little as the result of mixed micelles formation during the different stages for the structure changes of surfactant-liposomes micelles. The further added bile salts decreased the diameters and turbidities of liposomes. The liposome suspension underwent several rearrangements before small mixed micelles formed. And the diameter of liposomes changed regularly. The interaction of bile salts and liposomes is important for the further study of the behaviors of liposomes in vivo. The drug loaded and release properties of liposomes can also be well reflected by the interaction of liposomes and surfactants.

A Microwave High Power Static Induction Transistor with Double Dielectrics Gate Structure

The designing approaches and key fabricating technologies for high frequency high power double dielectrics gate static induction transistor (DDG SIT) with mixed non-saturating I-V characteristics are presented.The effects of parasitic gate-source capacitance (C gs) on the power performance of SIT are discussed.The main methods and considerations to diminish C gs,consequently to improve the high power performance are given.Synchronous epitaxy technology is the critical step to decrease C gs.The 7-μm pitch DDG SIT delivering output power >20W with >7dB power gain and >70% drain efficiency at 400MHz,and delivering output power >7W with >5dB power gain and >50% drain efficiency at 700MHz are successfully fabricated.

Pharmaceutical Characteristics of Daunorubicin Stealth Liposomes

This report studied on pharmaceutical characteristics of the stealth liposome containing dau-norubicin (DNR). The shape, size, entrapment efficiency and stability of the daunorubicin stealth liposomes (DNRSL) were examined. Visible spectrophotometry and the HPLC method were established for determination of the DNR in the DNRSL. The release of DNR from DNRSL in HBS (pH 7.5) and rat serum at 37 oC were examined. The results showed that the DNRSL had high entrapment efficiency (>85%), small size and slow release.

Preparation of liposomal fluconazole gel and in vitro transdermal delivery

Aim Liposomal fluconazole gel was prepared and its properties were studied. Methods The fluconazole liposomes were prepared by film dispersion method. Their shapes and sizes were observed by transmission electronic microscope and particle size analyzer, respectively. The skin permeation of liposomal gel was studied on rat skin by permeation cell. Results The entrapment efficiency of flueonazole liposomes was 47.68%. The fluconazole liposomes were oval or round in shape, and their average diameter was 250 ± 8 nm. The accumulative skin permeation of liposomal fluconazole gel （25.27%） was lower than that of non-liposomal fluconazole gel （36.72%）, but fluconazole retained in rat skin of liposomal gel （162 ± 15 μg·cm^-2） was higher than that of nonliposomal gel （48 ± 6μg·cm^-2）. Conclusion Liposomal fluconazole gel can significantly increase the deposited amounts of fluconazole in rat skin and it may be beneficial for topical use.

Production of Somatic Hybrid Plants Between Two Types of Wheat Protoplasts and the Protoplasts of Haynaldia villosa

小麦 (TriticumaestivumL .)济南 177的两种原生质体 ,一种来自快速生长的悬浮细胞 ,它们因长期继代而丧失分化能力 ,其染色体只有 2n =2 4～ 2 8;另一种来自可以再生的愈伤组织 ,其原生质体不能持续分裂。它们中任一种与UV照射过的簇毛麦原生质体融合均不能再生植株。然而当它们混合在一起作为受体时 ,能够获得再生绿色植株。细胞核基因和胞质基因的分析证明这些绿色植株是杂种。以上事实说明这两种原生质体在融合时存在某些互补的关系 ,讨论了这种融合方式的可能作用及重要性。

Impact of light-weight external thermal insulation materials on building surrounding thermal environment in summer

The method for calculating wall surface heat storage coefficient was introduced,and the coefficients of several common walls with light-weight external thermal insulation materials and the traditional solid clay brick wall were calculated.In order to study the impact of light-weight external thermal insulation materials,a contrasting experiment was carried out between an external insulated room and an uninsulated room in August,2010,in Chongqing,China.The result shows that outside surface heat storage coefficient of the insulated wall is much less than that of the traditional wall.However,during sunny time,the surface temperature of external walls of the insulated room is obviously higher than that of the uninsulated room.In different orientations,due to different amounts of solar radiation and being irradiated in different time,the contrasting temperature difference(CTD) appears different regularity.In a word,using light-weight external thermal insulation materials has a negative impact on building surrounding thermal environment and people's health.Finally,some suggestions on how to eliminate the impact,such as improving the surface condition of the building envelop,and plating vertical greening,are put forward.

Effects of Thidiazuron,basal medium and light quality on adventitious shoot regeneration from in vitro cultured stem of Populus alba×P. berolinensis

The effect of Thidiazuron （TDZ）, basal media and light quality on adventitious shoot regeneration from in vitro cultured stem of Populus albaxP berolinensis were determined to establish a high efficiency shoot regeneration system from stem explants of P. alba^P berolinensis. Stems ofPopulus alba^P berolinensis were collected from cultured shoots in vitro derived from dormancy buds of 3-year-old seedlings. The stem explants were cultured on MS medium containing 0.02-mg·L-1NAA （naphthaleneacetic acid）, and 0.1, 0.3, 0.5 and 1.0 mg·L-1 concentrations of TDZ to determine the effect of TDZ on shoot regeneration. Three basal media, i.e. MS, woody plant medium （WPM） and B5, were used to test their influences of different media on adventitious shoot regeneration. Green, red, blue and yellow plastic films in comparison with florescent light as control were used to observe their effects on shoot regeneration. The results showed that differ- ent concentrations of TDZ had an evident influence on shoot regeneration. Lower concentration of TDZ （0.1 mg·L-1） resulted in more ad- ventitious shoot regeneration and higher concentration of TDZ （〉0.1 mg·L-1） inhibited shoot regeneration. Among different media, MS medium exhibited a high efficiency for shoot regeneration, followed by WPM medium, while B5 medium inhibited shoot regeneration. Normal light and yellow light exhibited better effects on shoot regeneration, compared with other light.

Thyroid hormone regulation of apoptotic tissue remodeling during anuran metamorphosis

Anuran metamorphosis involves systematic transformations of individual organs in a thyroid hormone (TH)-dependent manner. Morphological and cellular studies have shown that the removal of larval or- gans/tissues such the tail and the tadpole intestinal epithelium is through programmed cell death or apop- tosis. Recent molecular investigations suggest that TH regulates metamorphosis by regulating target gene expression through thyroid hormone receptors (TRs), which are DNA-binding transcription factors. Cloning and characterization of TH response genes show that diverse groups of early response genes are induced by TH. The products of these TH response genes are believed to directly or indirectly affect the expression and/or functions of cell death genes, which are conserved at both sequence and function levels in different animal species. A major challenge for future research lies at determining the signaling pathways leading to the activation of apoptotic processes and whether different death genes are involved in the regulation of apoptosis in different tissues/organs to effect tissue-specific transformations.

Structure of Protonated Heterodimer of Proline and Phenylalanine:Revealed by Infrared Multiphoton Dissociation Spectroscopy and Theoretical Calculations

The infrared multiphoton dissociation(IRMPD)spectrum of the protonated heterodimer of Pro Phe H+,in the range of 2700-3700 cm^-1,has been obtained with a Fourier-transform ion cyclotron mass spectrometer combined with an IR OPO laser.The experimental spectrum shows one peak at 3565 cm^-1 corresponding to the free carboxyl O-H stretching vibration,and two broad peaks centered at 2935 and 3195 cm^-1.Theoretical calculations were performed on the level of M062 X/6-311++G(d,p).Results show that the most stable isomer is characterized by a charge-solvated structure in which the proton is bound to the unit of proline.Its predicted spectrum is in good agreement with the experimental one,although the coexistence of salt-bridged structures cannot be entirely excluded.