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1.
目的:探讨SD大鼠肺微血管周细胞(rat pulmonarymicrovessel pericytes,RPMPC)的分离、培养与鉴定方法。方法:采用机械剪切、Ⅰ型胶原酶消化法和微孔过滤结合超高速离心法分离大鼠肺微血管片段,用含15%胎牛血清(FBS)的高糖培养基(DMEM)进行培养,倒置显微镜观察原代RPMPC的形态及生长特性。免疫荧光法检测神经元-胶质抗原2(neuron-glial antigen 2,NG2),α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、结蛋白(desmin)和CD31相关抗原的表达,同时应用免疫细胞化学法检测血小板源性生长因子受体β(PDGFR-β)的表达。CCK-8测定周细胞生长曲线。通过周细胞-内皮细胞共培养成管实验检测细胞成管能力。结果:本方法培养获取的RPMPC纯度较高,并能连续传代。细胞48 h后爬出,呈长梭形、三角形等不规则形,8~10 d细胞汇合,呈栅栏或旋涡状生长,无接触性抑制,前期可见有少量内皮细胞伴随生长,单核偶见双核,核呈卵圆形,胞浆丰富。PDGFR-β、α-SMA、NG2、desmin染色阳性,CD31阴性;周细胞与内皮细胞共培养形成管腔结构。结论:通过本方法能够获得纯度较高的肺微血管周细胞,且所获细胞具有周细胞的特性及功能。  相似文献   
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Antiviral activity against H1N1 influenza was studied using ethnic medicinal plants of South India. Results revealed that Wrightia tinctoria (2.25 μg/ml) was one of the best antidotes against H1N1 virus in terms of inhibitory concentration of 50% (IC50) whereas the control drug Oseltamivir showed 6.44 μg/ml. Strychnos minor, Diotacanthus albiflorus and Cayratia pedata showed low cytotoxicity (>100) to the MDCK (Malin darby canine kidney) cells by cytotoxicity concentration of 50% (CC50) and possessed antiviral activity suggesting that these plants can be used as herbal capsules for H1N1 virus. W. tinctoria and S. minor showed high therapeutic indexes (TI) such as 12.67 and 21.97 suggesting that those plants can be used for anti-viral drug development. The CC50 values of Eugenia singampattiana (0.3 μg/ml), Vitex altissima (42 μg/ml), Salacia oblonga (7.32 μg/ml) and Salacia reticulata (7.36 μg/ml) resulted in cytotoxicity of the MDCK cells, due to their high phenolic content. Findings from this study state that the plant W. tinctoria can be a potent source for third generation anti-viral drug development against H1N1.  相似文献   
4.
Cardiac stem cells are described in a number of mammalian species including humans. Cardiac stem cell clusters consisting of both lineage-negative and partially committed cells are generally identified between contracting cardiac myocytes. In the present study, c-kit+, Sca+, and Isl1+ stem cells were revealed to be located inside the sarcoplasm of cardiac myocytes in myocardial cell cultures derived from newborn, 20-, and 40-day-old rats. Intracellularly localized cardiac stem cells had a coating or capsule with a few pores that opened into the host cell sarcoplasm. The similar structures were also identified in the suspension of freshly isolated myocardial cells (ex vivo) of 20- and 40-day-old rats. The results from this study provide direct evidence for the replicative division of encapsulated stem cells, followed by their partial cardiomyogenic differentiation. The latter is substantiated by the release of multiple transient amplifying cells following the capsule rupture. In conclusion, functional cardiac stem cells can reside not only exterior to but also within cardiomyocytes.  相似文献   
5.
Biotherapeutic proteins represent a mainstay of treatment for a multitude of conditions, for example, autoimmune disorders, hematologic disorders, hormonal dysregulation, cancers, infectious diseases and genetic disorders. The technologies behind their production have changed substantially since biotherapeutic proteins were first approved in the 1980s. Although most biotherapeutic proteins developed to date have been produced using the mammalian Chinese hamster ovary and murine myeloma (NS0, Sp2/0) cell lines, there has been a recent shift toward the use of human cell lines. One of the most important advantages of using human cell lines for protein production is the greater likelihood that the resulting recombinant protein will bear post-translational modifications (PTMs) that are consistent with those seen on endogenous human proteins. Although other mammalian cell lines can produce PTMs similar to human cells, they also produce non-human PTMs, such as galactose-α1,3-galactose and N-glycolylneuraminic acid, which are potentially immunogenic. In addition, human cell lines are grown easily in a serum-free suspension culture, reproduce rapidly and have efficient protein production. A possible disadvantage of using human cell lines is the potential for human-specific viral contamination, although this risk can be mitigated with multiple viral inactivation or clearance steps. In addition, while human cell lines are currently widely used for biopharmaceutical research, vaccine production and production of some licensed protein therapeutics, there is a relative paucity of clinical experience with human cell lines because they have only recently begun to be used for the manufacture of proteins (compared with other types of cell lines). With additional research investment, human cell lines may be further optimized for routine commercial production of a broader range of biotherapeutic proteins.  相似文献   
6.
目前,国内普遍采用亮菌固体发酵工艺生产亮菌制剂。采用小型发酵罐液体深层发酵和液体静置发酵对亮菌发酵工艺进行优化研究。液体深层发酵采用28℃,200 r/min,通气量1∶1 v/v·m,培养7 d,亮菌干重为16.55g/L,其中菌丝体中多糖含量为5.42%,蛋白含量为1.75%;液体静置发酵采用500 mL三角瓶,28℃,150 r/min,摇瓶3 d后静置发酵14 d,亮菌干重可达10.69 g/L,发酵液中多糖含量为1.016 g/L,蛋白含量为0.320 g/L。对液体静置发酵进一步研究发现其发酵液中亮菌甲素含量可达3.118 mg/L。由此可见,两种发酵方式在保证生物量和活性成分的前提下,缩短了发酵周期,均优于传统的固体发酵工艺,值得工业生产借鉴。  相似文献   
7.
Advances in soil microbial ecology and the biodiversity   总被引:3,自引:0,他引:3  
Recent studies on the colony formation of soil bacteria opened the way to categorize soil bacteria into colony forming curve (CFC) groups of different growth rates. A bacterial culture collection comprising organisms from every CFC group is called an ecocollection. Outlines of ECs of paddy soil 1992 and grassland soil 1987 and 1992 were described. Phylogenetic studies by 16S rDNA sequencing showed a great diversity of culture strains of the ecocollections (EC). A set of alternative concepts was proposed; the active and the quiescent forms of bacterial cells in soil. The former is able to be cultivated and thus counted by the plate method, while the latter is not unless it transforms into the former. Based on the results several points required for extensive cataloguing of soil bacteria were noted.  相似文献   
8.
Two distinct cDNAs for 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) were obtained from a glyphosate-tolerant tobacco cell line. The cDNAs were 89% identical and the predicted sequences of the mature proteins were greater than 83% identical with EPSPS proteins from other plants. Tobacco EPSPS proteins were more similar to those from tomato and petunia than Arabidopsis. One cDNA clone, EPSPS-1, represented a gene that was amplified in glyphosate-tolerant cells, while the gene for EPSPS-2 was unaltered in these cells. Consequently, EPSPS-1 mRNA was more abundant in tolerant than unselected cells, whereas EPSPS-2 mRNA was at relatively constant levels in these cell lines. Exposure of unselected cells and tobacco leaves to glyphosate produced a transient increase in EPSPS mRNA. However, glyphosate-tolerant cells containing amplified copies of EPSPS genes did not show a similar response following exposure to glyphosate. A significant proportion of the EPSPS gene amplification was maintained when tolerant cells were grown in the absence of glyphosate for eight months. Plants regenerated from these cells also contained amplified EPSPS genes.  相似文献   
9.
Experiments on three autumn-heading cauliflower genotypes (2 hybrids and a genotype selected from a population) were conducted to study different factors affecting anther culture. Culture conditions of the donor plants proved to be important: the best results were obtained during spring in a greenhouse where the temperature was maintained between 10 and 20°C. Overall winter and spring seemed more suitable than summer and early autumn for culture establishment. The optimal bud development stage depended on the genotype: for the hybrid 702, the greatest number of embryos for 100 plated anthers was obtained at the uninucleate pollen stage of the microspores; for V23.2 and 703, the optimal stage of the buds corresponded to the first mitotic division. Sucrose proved to be the best carbon supply for embryogenesis with an optimal concentration of 140 g l-1. The addition of a cytokinin (BAP) in the medium led to lower embryo production, and this negative effect increased when the hormone concentration in the medium increased. The use of liquid medium and a dark incubation period immediately after the high temperature treatment were favourable for embryogenesis.  相似文献   
10.
Abstract. Maintenance of realistically low solution P concentrations under controlled conditions is a major difficulty in studies of P nutrition. In this report, we describe a relatively simple and economical sand culture system capable of sustaining plant growth to maturity under controlled yet realistic P regimes. The system uses Al2O3 as a solid-phase P buffer, and modern process control technology to control irrigation and addition of other mineral nutrients. Aspects of the design, use and potential applications of automated solid-phase systems are discussed. The system was used to grow Phaseolus vulgaris to matarity at 0.4 mmol m3, 1.0 mmol m3 and 27 mmol m3 P with and without mycorrhizal inoculation. At flowering, low solution P concentrations were associated with reduced leaf concentrations of P in nonmycorrhizal plants, and reduced leaf concentrations of Ca in both mycorrhizal and nonmycorrhizal plants. Mycorrhizal inoculation increased leaf P, K, Mg and Mn concentrations, but reduced leaf N concentration. Low P regimes reduced final seed yield by diminishing both the number of pods per plant and the number of seeds per pod. Mycorrhizal inoculation significantly enhanced seed yield under low P regimes by increasing seed weight, the number of pods per plant, and the number of seeds per pod.  相似文献   
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