基于果蝇口腔感染的肠道训练免疫模型研究（英文）

目的 利用果蝇作为遗传工具从个体和分子层面研究果蝇的训练免疫效应,并为后续深入研究其分子机制提供依据。方法 首先构建无菌果蝇模型,在此基础上构建果蝇成虫及跨发育阶段训练免疫模型,用两种革兰氏阴性菌——胡萝卜软腐欧文氏菌（Erwinia carotovora carotovora 15）及铜绿假单胞菌（Pseudomonas aeruginosa）分别经口腔感染果蝇。在第一次感染完全消退后进行再次感染,然后通过比较果蝇在两个感染阶段的存活率和细菌量来衡量训练免疫的潜在效果。通过实时荧光定量PCR检测相应先天免疫相关基因的表达水平,研究革兰氏阴性菌对免疫缺陷（IMD）通路的诱导作用。结果 果蝇成虫及幼虫初次感染均可提高二次感染后的生存率、细菌清除效率及死亡时能承受的最高细菌负荷;二次感染的果蝇中,IMD通路中免疫反应基因的基础表达比未感染的高,这提供了获得感染抗性的分子基础;果蝇的免疫反应主要发生在中肠,二次免疫比初次免疫的效应更迅速且剧烈;二次免疫的果蝇中,肠道干细胞的数量显著多于初次感染。结论 果蝇肠道中强大的训练免疫可由同源或异源革兰氏阴性菌口腔感染引发,且免疫记忆可在整个发育阶段持...     

Human pluripotent stem cell-derived extracellular vesicles: From now to the future

Extracellular vesicles (EVs) are nanometric particles that enclose cell-derived bioactive molecules in a lipid bilayer and serve as intercellular communication tools. Accordingly, in various biological contexts, EVs are reported to engage in immune modulation, senescence, and cell proliferation and differentiation. Therefore, EVs could be key elements for potential off-the-shelf cell-free therapy. Little has been studied regarding EVs derived from human pluripotent stem cells (hPSC-EVs), even though hPSCs offer good opportunities for induction of tissue regeneration and unlimited proliferative ability. In this review article, we provide an overview of studies using hPSC-EVs, focusing on identifying the conditions in which the cells are cultivated for the isolation of EVs, how they are characterized, and applications already demonstrated. The topics reported in this article highlight the incipient status of the studies in the field and the significance of hPSC-EVs’ prospective applications as PSC-derived cell-free therapy products.     

Exosomes for angiogenesis induction in ischemic disorders

Ischaemic disorders are leading causes of morbidity and mortality worldwide. While the current therapeutic approaches have improved life expectancy and quality of life, they are unable to “cure” ischemic diseases and instate regeneration of damaged tissues. Exosomes are a class of extracellular vesicles with an average size of 100–150 nm, secreted by many cell types and considered a potent factor of cells for paracrine effects. Since exosomes contain multiple bioactive components such as growth factors, molecular intermediates of different intracellular pathways, microRNAs and nucleic acids, they are considered as cell-free therapeutics. Besides, exosomes do not rise cell therapy concerns such as teratoma formation, alloreactivity and thrombotic events. In addition, exosomes are stored and utilized more convenient. Interestingly, exosomes could be an ideal complementary therapeutic tool for ischemic disorders. In this review, we discussed therapeutic functions of exosomes in ischemic disorders including angiogenesis induction through various mechanisms with specific attention to vascular endothelial growth factor pathway. Furthermore, different delivery routes of exosomes and different modification strategies including cell preconditioning, gene modification and bioconjugation, were highlighted. Finally, pre-clinical and clinical investigations in which exosomes were used were discussed.     

Human and animal mesenchymal progenitor cells from bone marrow: Identification of serum for optimal selection and proliferation

Summary An undifferentiated subset of cells within the stromal cell population of bone marrow in postnatal mammals retains the capacity to differentiate along osteogenic, adipogenic, fibroblastic, and chondrogenic lines. These cells, which are referred to as mesenchymal stem cells (MSCs), can be maintainedin vitro and expanded in number through a process of subculturing. MSCs are maintained in culture in medium supplemented with 10% fetal bovine serum (FBS). It is believed that certain, as yet unidentified, serum components play critical roles in the attachment and proliferation of MSCs. Commercially available FBS is poorly characterized and may vary in composition and quality from lot to lot. This study describes a method for the selection of lots of FBS that best support maintenance of the undifferentiated state, mitotic expansion of MSCsin vitro, and retention of multilineage developmental potential in response to appropriate cues.     

Stem deformity inPinus radiata plantations in south-eastern Australia

Plantations of radiata pine (P. radiata D.Don) on soils previously under legume based pastures have a high incidence of stem deformity compared with forest soils. A comparison of soil properties and tree nutrition of 5 to 7 year-old radiata pine on former pastures in the first part of the study showed that stem deformity was strongly correlated with mineralisation of soil N and in particular with nitrification. Other soil properties that have changed as a result of pasture improvement, e.g. pH, available P and Mn, were only partially correlated with stem deformity. In the second part of the study, the role of N availability and other soil properties in the expression of deformity was further investigated in a separate field experiment on soils formerly under native eucalypt forest, tobacco cropping, and improved pasture. Young radiata pine plantings were treated with lime, phosphorus, and nitrogen applied as urea and sodium nitrate. Liming increased soil pH by around 1.5 units, raised exchangeable Ca²⁺ and decreased available Mn. Soil mineral N content was only marginally affected by liming. Superphosphate increased soil available P and raised levels of P in foliage. Changes in soil pH, availability of P, Mn, and B did not affect growth or stem deformity at any of the sites. In contrast, application of N fertilisers at 200 and 600 kg N ha^-1 increased mineral N content and stimulated nitrification, particularly at the forest site. The high rate of N fertiliser increased basal area at the forest site by 45%, but also raised the level of stem deformity from 12% to 56%. At the tobacco and pasture sites, this treatment did not increase growth and did not significantly raise stem deformity above the already high basic level of deformity (63%). Implications of stem deformity in young plantations of radiata pine on potential utilisation later in the rotation are discussed.     

Influence of gibberellin biosynthesis inhibitors on stem elongation and floral initiation on in vitro chicory root explants under dark and light conditions

Root explants of chicory (Cichorium intybus L.) were cultured in vitro under continuous light or darkness. On a standard medium (no plant growth regulators added), flowering-stems were initiated under continuous light while under continuous dark, vegetative-stems were formed. Different types of GA (gibberellin) biosynthesis inhibitors were added to the culture medium. Paclobutrazol and compounds belonging to the group of cyclohexanetriones clearly reduced flowering-stem growth under light conditions and vegetative-stem growth under dark conditions. Under light conditions, flower bud initiation was not affected. These and other results suggest that GA₁ may be synthesized during the in vitro culture period and that it controls flowering-stem growth but not floral initiation.Abbreviations CCC chlormequat chloride - GA gibberellin - LAB 198 999 3,5-dioxo-4-butyryl-cyclohexane carboxylic acid ethyl ester - BAS 111..W 1-phenoxy-3-(1H-1,2,4-triazol-1-yl)-4-hydroxy-5,5-dimethylhexane     

The basic organization of the Plathelminthes

The basic organization of the Plathelminthes is summarized. Special attention is given to epidermal structures, musculature, extracellular matrices, nervous system and sensory structures, digestive system, totipotent stem cells, protonephridia, reproductive system and life cycle. The latest common ancestor of the Plathelminthes lacked any parenchymal cells and tissues; Plathelminthes do not represent Parenchymia. Discussions concerning the relationships of the Plathelminthes with other Metazoa must be based on the characteristics of the plathelminth stem species.     

Disinfection Alternatives for Control of Ditylenchus dipsaci in Garlic Seed Cloves

Hot-water dips with and without the additives abamectin and sodium hypochlorite were evaluated for control of Ditylenchus dipsaci infection of garlic seed cloves. All treatments were compared to hot water-formalin clove dip disinfection and to nontreated infected controls for garlic emergence, midseason infection, bulb damage, and yield at harvest in field plots in 12 experiments. Hot-water treatments without additives only partially controlled D. dipsaci when a warming presoak dip (38 C) of 30, 45, or 60 minutes'' duration was followed by a hot-water dip (49 C) of 15-30 minutes'' duration. Exposure to 49 C for 30 minutes caused slight retardation of garlic emergence, although normal stand was established. Abamectin at 10-20 ppm as the 20-minute hot dip (49 C) or as a 20-minute cool dip (18 C) following a 20-minute hot-water dip and sodium hypochlorite at 1.052-1.313% aqueous solution as the 20-minute hot dip were highly effective in controlling D. dipsaci and were noninjurious to garlic seed cloves. None of these treatments was as effective as a hot water-formalin dip and were noneradicative, but showed high efficacy on heavily infected seed cloves relative to nontreated controls. Abamectin was most effective as a cool dip. These abamectin cool-dip (following hot-water dip) and sodium hypochlorite hot-dip treatments can be considered as effective alternatives to replace formalin as a dip additive for control of clove-borne D. dipsaci. Sodium hypochlorite was less effective as the cool dip, and at concentrations of 1.75-2.63% was phytotoxic to garlic.     

小鼠造血干细胞增殖和分化的分子生物学证据

本文采用Ｙ染色体特异的性别决定基因（Ｓｒｙ）作为新的细胞遗传标志,通过ＰＣＲ技术来追踪观察造血干细胞的增殖与分化性能。该方法具有简便、灵敏和特异等优点。雌性受体小鼠输注雄鼠骨髓细胞和１３天脾结节（ＣＦＵ－Ｓ１３）细胞后,Ｓｒｙ ＰＣＲ测试受体小鼠的ＣＦＵ－Ｓ结果表明,它们均为供体来源的ＸＹ细胞。用Ｓｒｙ ＰＣＲ骨髓细胞和骨髓中脾结节生成细胞（ＣＰＵ－Ｓ）的长期重建造血能力,结果表明,在存活雌性小鼠