rhEGF缓释微球对糖尿病皮肤溃疡创面修复的 作用

采用W/O/W方法制备聚乳酸-羟基乙酸共聚物(PLGA)载重组人表皮生长因子(rhEGF)缓释微球, 表征了缓释微球形貌和粒径分布, 研究了体外释放行为, 进行了细胞实验和动物实验. 结果显示：微球形貌规则, 粒径均匀; 药物包封率达85.6%; 缓释时间达24 h. 细胞实验表明, 微球比rhEGF原液具有更好的促进细胞增殖作用; 通过观察动物实验中溃疡面积变化、组织病理切片和PCNA表达, 发现微球组治疗效果优于生长因子原液组和空白对照组, 并且具有显著性差异. 本研究为rhEGF缓释微球技术的临床应用提供了重要的科学依据.     

PLGA-5-氟尿嘧啶缓释微球治疗结直肠癌裸鼠的探讨

目的研究PLGA-5-氟尿嘧啶缓释微球瘤周给药对结直肠癌移植瘤的治疗效果。方法将60只结直肠癌荷瘤鼠随机分为6组,每组10只。A、B组瘤周注射PLGA-5-氟尿嘧啶缓释微球,5-氟尿嘧啶剂量分别为200mg/kg和100 mg/kg;C、D组瘤周注射5-氟尿嘧啶注射液,5-氟尿嘧啶剂量分别为200 mg/kg和100 mg/kg;E组瘤周注射PLGA微球,800 mg/kg;F组不给予任何治疗。于0、3、6、9、12、15d观察裸鼠生存状况、称体重、测量肿瘤大小。15d时处死动物,称瘤重,计算抑瘤率,绘制肿瘤生长曲线;取血行白细胞计数、肝肾功能检查。结果A、B组肿瘤生长曲线平缓,15 d时A、B组肿瘤体积与C、D、E、F组比较,结果差异有显著性,C、D组肿瘤体积与E、F组比较差异无显著性;A、B组抑瘤率分别为75%和62%,与C、D组比较,结果差异有显著性;A、B、C、D、E组体重在0 d及15 d与F组比较,差异无显著性,15 d时各组白细胞计数及肝肾功能检查值均在正常范围。结论PLGA-5-氟尿嘧啶缓释微球瘤周给药能有效抑制结直肠癌移植瘤的生长,且无明显的毒副作用。     

担载b-FGF的PLGA微球复合明胶支架的体外释放研究

目的:研究担载碱性成纤维细胞生长因子(b-FGF)微球复合明胶支架的外形特征、孔径、孔隙率及体外释放动力学,以期构建具有缓释功能、高孔隙率的担载细胞因子的新型复合明胶支架。方法:本文利用冷冻相分离法和S/O/W法先将b-FGF水溶液包裹于PLGA微球中,然后埋置于明胶溶液中制备为多孔复合明胶支架。分别对微球的形态和复合明胶支架的基本形态、孔径、孔隙率进行表征,通过Elisa法测定b-FGF在复合明胶支架中的体外释放行为。结果:制备成形态良好的三维复合明胶支架,其孔隙率为82.90%±1.45%,孔径范围为150~300μm,复合明胶支架中b-FGF在体外缓慢释放20余天。结论:担载蛋白微球复合明胶支架不仅满足组织工程支架的要求,还能有效缓释细胞因子,为细胞和组织生长提供良好的微环境,为进一步应用于组织工程领域提供了可能。     

Cytohesins介导EGFR 通路在结直肠癌细胞增殖中的作用

目的:研究Cytohesins介导EGFR通路在结直肠癌细胞增殖中的作用。方法:选择人结直肠癌细胞系HT-29作为研究细胞,采用免疫荧光检测结直肠癌细胞系HT29中EGFR表达情况,Secin H3阻断结直肠癌细胞系HT29细胞内cytohensins观察细胞内EGFR通路激活情况,MTT法检测细胞增殖情况。结果:EGF+Secin H3组细胞内p-EGFR水平显著低于EGF组(P0.05)。第3、5天,各组细胞增殖情况存在显著差异(F=38.072,P0.05),其中EGF组显著高于Secin H3阻断组(P0.05)和对照组(P0.05),对照组吸光度值显著高于Secin H3阻断组(P0.05)。结论:EGF与结直肠癌细胞的增殖密切相关,通过阻断Cytohesins介导EGFR通路能够显著抑制结直肠癌细胞的增殖。     

幼儿舌脱落细胞形态与口气关系的研究分析

目的:比较分析高口气值组和低口气值组幼儿舌脱落细胞形态计量学参数及分类计数上的差异,探讨口气是否影响舌粘膜上皮细胞的角化、凋亡过程。方法:3-5岁幼儿40名,其中高口气值组幼儿20名,低口气值组幼儿20名,,取舌背中1/3脱落细胞,制作细胞涂片、H.E染色。应用计算机图像分析系统对舌脱落细胞进行形态计量学检测和分类计数。结果:高口气值组幼儿的舌脱落细胞的各类细胞的细胞形态较低口气值组幼儿小,且细胞核也更小。中层细胞、完全角化细胞计数在两组间的差异无统计学意义(P>0.05),高口气值组角化前细胞计数明显高于低口气值组(P<0.01),而高口气值组不全角化细胞计数明显低于低口气值组(P<0.01)。结论:高口气值组幼儿的舌脱落细胞较小,细胞角化程度较低,凋亡速度较慢。     

胶原酶缓释微球的研究

目的:本实验旨在开发一种胶原酶缓释微球制剂,用以治疗手掌腱膜挛缩症,以减小现有水针剂的不足。方法:利用水相-水相乳化法和低温冷冻相分离法两种方法制备载药颗粒,分别将其包裹于PLGA微球内,制备成胶原酶微球,并用扫描电镜考察其表面形态,对其粒径进行统计学分析,测定体外释放行为并比较。结果:两种方法制备的微球表面光滑圆整,都可以达到缓释的效果,一个星期内释药完全。水相-水相乳化法制备的微球比低温冷冻相分离制备的微球粒径大,且具有统计学差异(P0.05)。水相-水相乳化法制备的微球粒径较均一,其体外释放更加平缓,突释较小。结论:本研究制得的胶原酶微球能实现理想的体外缓释效果,解决了现有技术中胶原酶粉针剂型快速释放并分散的问题。     

载荷壳聚糖微球的海藻酸钠水凝胶的制备

目的:在支架材料上引入具有控释行为的微球,旨在通过微球包裹生长因子,通过生长因子的缓慢释放从而促进种子细胞的生长分化。方法:本实验通过在海藻酸钠水凝胶中负载具有控释功能的壳聚糖微球,并通过在微球中包载溶菌酶从而达到控制壳聚糖降解速率的功效。实验研究了不同搅拌速度下壳聚糖微球的形貌及粒径大小,通过扫描电镜对壳聚糖微球及复合支架的形貌进行了观察,通过紫外光吸收法测试了微球的载药量及包封率,并研究了壳聚糖微球在体外的降解行为等。结果:制备的壳聚糖微球表面较光滑,溶菌酶的包封率在25.78%-41.89%之间,载药量在15.20%-24.44%之间。包封溶菌酶的微胶囊在降解9天后壳聚糖分子量下降了70.40%,载荷微球的复合凝胶孔洞增多,孔洞大小均匀。结论:此复合材料有望作为载荷软骨相关生长因子的支架模型,从而解决软骨组织工程中种子细胞匮乏的问题。     

绿色荧光蛋白标记人脐带间充质干细胞大鼠卵巢移植的实验观察

目的观察人脐带间充质干细胞(MSCs)移植于大鼠卵巢后存活的情况,为MSCs参与动物实验提供实验依据。方法以腺病毒介导绿色荧光蛋白(GFP)基因体外转染MSCs 48 h,于大鼠腹腔卵巢注射移植,于注射移植后1h及移植后3、7、21 d取材并在荧光显微镜下观察MSCs的存活情况。取材石蜡切片行苏木精-伊红(HE)染色观察移植细胞部位组织病理图像。结果 MSCs注射移植后3 d、7 d时GFP荧光表达较强,细胞轮廓清晰,与注射后1h平均吸光度值比较,移植后3、7 d检测荧光吸光度值差异均无统计学意义(P0.05);移植后21 d时GFP荧光表达较弱,吸光度值差异有统计学意义(P0.05)。术后大鼠组织切片光镜下移植的MSCs细胞清晰可见,无急性排斥反应特征出现。结论 MSCs在大鼠腹腔卵巢移植,其与异种个体组织相容性较好。     

高分子药物缓释用壳聚糖微球的制备

本文采用了先交联制备可溶胀的壳聚糖载体微球,后将模型高分子药物以被动吸咐方式担载在溶胀的微球内的两步法,制备缓释高分子药物微球,避免了高分子药物接触有机试剂引起的活性损失。     

一种白细胞介素 -12 缓释微球制备及体外表征

目的:开发一种白细胞介素-12(IL-12)长效缓释微球剂型。方法:采用水包油-油包固(S/O/W)法制备了白介素-12因子多糖微粒的聚乳酸-聚羟基乙酸共聚物(PLGA-PLA)微球,研究了微球的表面形态和粒径大小,并且运用ELISA方法考察了微球的体外释放效果和免疫活性。结果:本方法制备的白介素-12因子微球光滑圆整,体外缓释达45天,累积释放率近90%。结论:本方法制备的白介素-12因子微球,不仅具有有效地保护IL-12蛋白活性,同时实现长效缓释的目标,是一种可行的IL-12缓释方案。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various