固定化微球降解土壤中PAEs效果及影响因素

旨为研究土壤邻苯二甲酸酯污染修复中,固定化微球降解土壤中邻苯二甲酸酯的效果及影响因素。以海藻酸钠为载体,采用包埋法对课题组前期提取的微小杆菌进行固定化,比较固定化微球和游离菌降解土壤中邻苯二甲酸酯(Phthalates esters,PAEs)的效果及pH、温度、重金属、无机盐等对降解菌降解目标物的影响。结果显示:(1)在土壤环境相同条件下,固定化微球对邻苯二甲酸二甲酯(Dimethyl ortho-phthalate,DMP)、邻苯二甲酸二正丁酯(Di-n-butyl ortho-phthalate,DnBP)和邻苯二甲酸二(2-乙基己)酯(Bis(2-ethylhexyl)ortho-phthalate,DEHP)的降解效果高于游离菌,DMP在7 d可降解完全,DnBP在10 d内可降解完全,DEHP在20 d降解率63.73%;而游离菌则在15 d内完全降解DMP,20 d内完全降解DnBP,DEHP在20 d降解率48.77%;(2)不同pH值时,固定化微球对DMP、DnBP、DEHP的降解率均高于游离菌,pH9时,固定化微球对于DMP、DnBP、DEHP的降解率最高分别为96.81%、89.39%、58.35%;(3)不同温度,固定化微球对DMP、DnBP、DEHP的降解率也均高于游离菌,温度为30℃时,固定化微球对于DMP、DnBP、DEHP的降解效率达到最高,分别为96.27%、89.19%、59.01%;(4)重金属使游离菌对DMP、DnBP、DEHP降解率下降较多,而使固定化微球对DMP、DnBP的降解率仅下降了16.35%、9.95%,DEHP不仅没有降低,反而增加2.49%,说明重金属对游离菌起到很强的抑制作用,但对于固定化微球的降解效果影响较小;(5)盐碱条件下,中性盐极大降低了游离菌和固定化微球降解DMP、DnBP、DEHP的降解能力,碱性盐和混合盐对降解菌影响较小,且增强了固定化微球对DnBP、DEHP的降解能力。固定化微球降解PAEs效果明显高于游离菌,对外界环境有更好的适应能力,且对重金属、无机盐污染环境有一定的抵御能力。     

New embedding medium for sectioning undecalcified bone

Methylmethacrylate (MMA) is the most commonly used embedding medium for sectioning undecalcified bone; however, a number of problems exist with its use in a research laboratory. MMA requires a long infiltration time and temperature control, and it reacts with many polymers. We used Kleer Set resin? as an alternative embedding medium for sectioning undecalcified bone specimens. Fluorochrome labeled bone specimens were sectioned transversely using a ground section technique and longitudinally on a sledge macrotome. The slides were viewed using both transmitted light and epifluorescence microscopy. High quality sections were obtained using Kleer Set resin? for both sectioning techniques. We have shown that this new embedding medium is simpler, safer, quicker to use and does not interfere with visualization of fluorochromes.     

Effects and interaction of dietary calcium and non-phytate phosphorus for slow-growing yellow-feathered broilers during the starter phase

Calcium (Ca) and non-phytate phosphorus (NPP) are fundamental minerals for bone formation and growth, and optimizing their level is required in broiler production. This experiment was conducted to investigate the effect and interaction of dietary Ca and NPP on growth performance, tibial characteristics and biochemical variables for slow-growing yellow-feathered broilers during 1–28 d (the starter phase). Seven hundred and twenty hatchling female broilers were randomly divided into nine groups, which received three levels of Ca (0.80%, 0.90%, 1.00%) each with three levels of NPP (0.40%, 0.45%, 0.50%). The results showed: (1) Dietary Ca level influenced (P < 0.05) the feed to gain ratio (F:G) and average daily feed intake (ADFI). Compared with broilers provided 1.00% Ca, ADFI of birds provided with 0.80% or 0.90% Ca and F:G of those with 0.90% Ca were decreased (P < 0.05). Dietary NPP level did not affect (P > 0.05) growth performance of broilers. (2) Dietary Ca affected (P < 0.05) tibial length. Compared with birds provided with 0.80% Ca, the length of tibia was decreased (P < 0.05) in birds received 1.00% Ca. Interactions between dietary Ca and NPP were observed (P < 0.05) on ash content, breaking strength and bone density of tibia. These three characteristics were better when birds received 0.90% Ca and 0.40% NPP or 1.00% Ca and 0.45% NPP. (3) Dietary Ca significantly affected (P < 0.05) the activity of alkaline phosphatase (ALP) in serum with decreased activity in birds fed 0.80% or 0.90% Ca. The dietary NPP influenced (P < 0.05) the contents of Ca in serum. Serum Ca was increased when birds were provided 0.40% NPP compared with other levels (P < 0.05). Again, there was interaction between Ca and NPP in diet on the contents of phosphorus (P) in serum (P < 0.05). In conclusion, interactions occurred between dietary Ca and NPP level on tibial breaking strength, density, ash content, and the content of P in the serum of young yellow-feathered broilers. Furthermore, dietary Ca affected ADFI, F:G and serum ALP activity, and dietary NPP also affected the P content in serum. Considering all indicators, 0.90% Ca and 0.40% NPP are optimal for slow-growing yellow-feathered broilers during 1–28 d of age.     

兔后交叉韧带断裂后外侧胫骨平台退变的组织学研究

目的：探讨兔后交叉韧带（Posterior cruciate ligament,PCL）断裂对外侧胫骨平台组织学的影响。方法：48只家兔膝关节随机配对为实验侧和对照侧造模,造模后第4、8、16、24周各随机处死12只,行外侧胫骨平台大体观察、HE染色、免疫组化检测基质金属蛋白酶13（matrix metalloproteinase-13,MMP-13）、基质金属蛋白酶抑制剂1（Tisse inhibitor-1 of matrix metalloproteinasel,TIMP-1）表达。结果：①大体观察,随时间延长,实验组外侧胫骨平台软骨出现磨损,呈灰黄色,弹性差,骨赘形成。②组织学观察,随时间延长,胫骨平台软骨纤维化,细胞排列紊乱,簇聚细胞出现频率增加。⑧实验组MMP-13、TIMP—1表达均高于对照组,有显著性差异。P〈0．05。④实验组MMP-13、TIMP-1表达阳性率第4、8、16周逐渐升高,24周下降,各组比较有显著性差异,P〈0．05。结论：①兔膝关节PCL断裂会引起外侧胫骨平台软骨退行性变,且该退变随着时间的推移逐渐加重。②MMP-13与TIMP-1在PCL断裂膝关节外侧胫骨平台中的表达呈现先高后低的变化规律,造成MMP-13与T1MP-1的失衡,加速软骨退变。⑨MMP-13与T／MP-1表达增高提示MMP-13与TIMP—1可能参与了PCL断裂后外侧胫骨平台软骨的退变过程。     

Preparation of Adult Drosophila Eyes for Thin Sectioning and Microscopic Analysis

Drosophila has long been used as model system to study development, mainly due to the ease with which it is genetically tractable. Over the years, a plethora of mutant strains and technical tricks have been developed to allow sophisticated questions to be asked and answered in a reasonable amount of time. Fundamental insight into the interplay of components of all known major signaling pathways has been obtained in forward and reverse genetic Drosophila studies. The fly eye has proven to be exceptionally well suited for mutational analysis, since, under laboratory conditions, flies can survive without functional eyes. Furthermore, the surface of the insect eye is composed of some 800 individual unit eyes (facets or ommatidia) that form a regular, smooth surface when looked at under a dissecting microscope. Thus, it is easy to see whether a mutation might affect eye development or growth by externally looking for the loss of the smooth surface (''rough eye'' phenotype; Fig. 1) or overall eye size, respectively (for examples of screens based on external eye morphology see e.g.¹). Subsequent detailed analyses of eye phenotypes require fixation, plastic embedding and thin-sectioning of adult eyes.The Drosophila eye develops from the so-called eye imaginal disc, a bag of epithelial cells that proliferate and differentiate during larval and pupal stages (for review see e.g. ²). Each ommatidium consists of 20 cells, including eight photoreceptors (PR or R-cells; Fig. 2), four lens-secreting cone cells, pigment cells (''hexagon'' around R-cell cluster) and a bristle. The photoreceptors of each ommatidium, most easily identified by their light sensitive organelles, the rhabdomeres, are organized in a trapezoid made up of the six "outer" (R1-6) and two "inner" photoreceptors (R7/8; R8 [Fig. 2] is underneath R7 and thus only seen in sections from deeper areas of the eye). The trapezoid of each facet is precisely aligned with those of its neighbors and the overall anteroposterior and dorsoventral axes of the eye (Fig. 3A). In particular, the ommatidia of the dorsal and ventral (black and red arrows, respectively) halves of the eye are mirror images of each other and correspond to two chiral forms established during planar cell polarity signaling (for review see e.g. ³).The method to generate semi-thin eye sections (such as those presented in Fig. 3) described here is slightly modified from the one originally described by Tomlinson and Ready⁴. It allows the morphological analysis of all cells except for the transparent cone cells. In addition, the pigment of R-cells (blue arrowheads in Fig. 2 and 3) can be used as a cell-autonomous marker for the genotype of a R-cell, thus genetic requirements of genes in a subset of R-cells can readily be determined^5,6.     

兔VX2肝癌模型制作技术改良

目的探讨制作兔VX2肝癌模型的新技术、新方法。方法将新西兰兔30只随机等分为3组,分别为嵌插组、改良嵌插组和经皮穿剌组。分别按不同方法建立肝癌模型,于建模后第1、2、3周分别进行CT扫描,评估肿瘤大小。3周后处死动物进行解剖,观察肝脏成瘤及转移情况,比较各组转移率,并行常规病理组织学检查。结果 30只动物建模成功28只,成功率93%,经皮穿剌组有2只肝脏未见种植灶,嵌插组和改良嵌插组全部种植成功。改良嵌插组腹壁转移率显著低于嵌插组和经皮接种组。结论改良嵌插法3周内不会形成接种部位腹壁以及远处的转移,是一种理想的移植性肝癌模型建模方法。     

Electron-microscopic demonstration of olfactory-marker protein with protein G-gold in freeze-substituted,Lowicryl K11M-embedded rat olfactory-receptor cells

Summary In this study electron-microscopic immunocytochemistry was used to localize olfactory marker protein in olfactory epithelia. Rat olfactory-epithelial samples were rapidly frozen, freeze-substituted with acetone, embedded at low temperatures with Lowicryl K11M and labelled on the sections with polyclonal antibodies raised against olfactory marker protein and with protein G conjugated to colloidal gold. Apart from the aforementioned use of acetone, substitution was carried out in the complete absence of chemical fixation, i.e., neither aldehydes nor OsO⁴ were used. This procedure resulted in localization concurrent with a good ultrastructural preservation. Olfactory-marker protein was present throughout the cytoplasmic compartments of dendrites and dendritic endings of olfactory-receptor cells, but it was not found in organelles such as mitochondria. Olfactory-marker protein was found only in dendriticendings of olfactory-receptor cells mature enough to have given rise to cilia, but these cilia displayed less labelling than dendrites and dendritic endings. Olfactory-marker protein was not found in apices and microvilli of neighboring olfactory-supporting cells.     

荷斯坦奶牛瘤胃微生物元基因组Fosmid文库的构建与分析

采用包埋法提取荷斯坦奶牛瘤胃微生物大片段总DNA,纯化后脉冲场电泳回收大小为36～48 kb,与pcc2FOS vector连接,转染至大肠埃希菌EPI 300宿主细胞,构建瘤胃微生物Fosmid基因组文库.对文库进行鉴定,该文库平均插入片段大小约35 kb,共保存30 000个克隆,空载体率小于2%,库容达1 050 Mb.     

A modelling approach demonstrating micromechanical changes in the tibial cemented interface due to in vivo service

Post-operative changes in trabecular bone morphology at the cement-bone interface can vary depending on time in service. This study aims to investigate how micromotion and bone strains change at the tibial bone-cement interface before and after cementation. This work discusses whether the morphology of the post-mortem interface can be explained by studying changes in these mechanical quantities. Three post-mortem cement-bone interface specimens showing varying levels of bone resorption (minimal, extensive and intermediate) were selected for this study Using image segmentation techniques, masks of the post-mortem bone were dilated to fill up the mould spaces in the cement to obtain the immediately post-operative situation. Finite element (FE) models of the post-mortem and post-operative situation were created from these segmentation masks. Subsequent removal of the cement layer resulted in the pre-operative situation. FE micromotion and bone strains were analyzed for the interdigitated trabecular bone. For all specimens micromotion increased from the post-operative to the post-mortem models (distally, in specimen 1: 0.1 to 0.5 µm; specimen 2: 0.2 to 0.8 µm; specimen 3: 0.27 to 1.62 µm). Similarly bone strains were shown to increase from post-operative to post-mortem (distally, in specimen 1: −185 to −389 µε; specimen 2: −170 to −824 µε; specimen 3: −216 to −1024 µε). Post-mortem interdigitated bone was found to be strain shielded in comparison with supporting bone indicating that failure of bone would occur distal to the interface. These results indicate that stress shielding of interdigitated trabeculae is a plausible explanation for resorption patterns observed in post-mortem specimens.     

交锁髓内钉与经皮锁定钢板治疗胫骨骨折的临床对照研究

目的:探讨交锁髓内钉与经皮锁定钢板治疗胫骨骨折的疗效。方法:选取了100例胫骨骨折患者,按住院单双号分为两组,对照组(48例)给予交锁髓内钉,观察组(52例)给予经皮锁定钢板治疗。通过观察并记录疗效,围手术期指标及随访3个月的并发症发生情况,评价交锁髓内钉与经皮锁定钢板治疗胫骨骨折的疗效。结果:采用经皮锁定钢板内固定和交锁髓内钉治疗胫骨骨折,两种手术方法所需手术时间无统计学差异(P0.05),经皮锁定钢板内固定术术中出血量更少,术后观察组患者住院时间和骨折愈合时间更短(P0.05),术后3个月,观察组患者有效率明显高于对照组(P0.05),随访3个月期间,观察组并发症5例,发生率9.6%,对照组并发症12例,发生率25.0%,观察组并发症发生率明显低于对照组(P0.05)。结论:经皮锁定钢板对胫骨骨折具有较好的疗效,手术安全性高,并发症少,能促进骨折愈合,使患者尽早康复,值得临床推广使用。