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Rhizobia nodulating native Astragalus and Oxytropis spp. in Northern Europe are not well-studied. In this study, we isolated bacteria from nodules of four Astragalus spp. and two Oxytropis spp. from the arctic and subarctic regions of Sweden and Russia. The phylogenetic analyses were performed by using sequences of three housekeeping genes (16S rRNA, rpoB and recA) and two accessory genes (nodC and nifH). The results of our multilocus sequence analysis (MLSA) of the three housekeeping genes tree showed that all the 13 isolates belonged to the genus Mesorhizobium and were positioned in six clades. Our concatenated housekeeping gene tree also suggested that the isolates nodulating Astragalus inopinatus, Astragalus frigidus, Astragalus alpinus ssp. alpinus and Oxytropis revoluta might be designated as four new Mesorhizobium species. The 13 isolates were grouped in three clades in the nodC and nifH trees. 15N analysis suggested that the legumes in association with these isolates were actively fixing nitrogen.  相似文献   

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Human cytomegalovirus (HCMV) has been detected in various types of tumors. We studied the prevalence of HCMV in ovarian cancer and its relation to clinical outcome. Paraffin-embedded tissues obtained prospectively from 45 patients with ovarian cancer and 30 patients with benign ovarian cystadenoma were analyzed for expression of HCMV immediate-early protein (IE) and HCMV tegument protein (pp65) by immunohistochemistry. Plasma was analyzed for HCMV serology. HCMV-IgG levels were higher in patients with ovarian cancer or benign cystadenoma than in age-matched controls (P?=?.002, P?<?.0001, respectively). HCMV IgM was detected in 12% of ovarian cancer patients and 3% of patients with benign tumors but was absent in controls. In patients with ovarian cancer, higher IgG levels were associated with better outcomes (P?=?.04). Extensive HCMV-IE protein expression was detected in 75% of ovarian cancers and 26% of benign tumors; pp65 was detected in 67% of ovarian cancers and 14% of benign tumors. A higher grade of HCMV infection was associated with higher stage of disease. Extensive HCMV-pp65 expression was associated with shorter median overall survival than focal expression (39 versus 42.5?months, P?=?.03). At study closure, 58% of ovarian cancer patients with focal pp65 expression were alive versus 27% of patients with extensive pp65 expression (P?=?.03). Thus, HCMV proteins are detected at different levels in ovarian tumors and benign cystadenomas. Ovarian cancer patients with focal HCMV-pp65 expression in their tumors and high IgG levels against HCMV lived longer, highlighting a need for in-depth studies of the oncomodulatory role of HCMV in ovarian cancer.  相似文献   

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Summary Airborne pollen studies were carried out, by means of Burkard volumetric spore traps, at two different sites (the city of Stockholm and the suburb Huddinge) 15 km apart in the Stockholm region. Within the city of Stockholm the study was carried out in 1973–89 while in Huddinge the investigation period was 1977–82. In all the years under investigation the total pollen catch and the number of pollen types were higher in Stockholm than in Huddinge. The reason for this is not explained by the composition of the local vegetation surrounding the traps. It is concluded that parameters such as qualitative changes in the daily catches and occurrence during the main pollen season are more important than the absolute daily figures. The cyclic trends in the local annual sums over a long period of years do not show any periodicity that is altogether regular and reliable.  相似文献   

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INTRODUCTION: The presence of KRAS mutations in patients with metastatic colorectal cancer (mCRC) predicts poor response to agents targeting the EGFR. Even in patients with RAS wild type (WT) tumors, resistance eventually develops due to multiple mechanisms, including the expansion of previously undetected KRAS mutated clones. In this feasibility study, we aimed to detect KRAS exon 2 mutations in serial samples of circulating tumor cells (CTCs) of RAS WT patients with mCRC captured by the Isolation by Size of Epithelial Tumor cells (ISET) system. METHODS: CTC isolation using the ISET system was performed from prospectively collected blood samples obtained from patients with RAS and BRAF WT mCRC prior to first-line therapy initiation, at first imaging assessment and on disease progression. CTCs were enumerated using hematoxylin & eosin and CD45 double stain on a single membrane spot. DNA was extracted from 5 spots and KRAS exon 2 mutations were detected using a custom quantitative Polymerase Chain Reaction (qPCR) assay. RESULTS: Fifteen patients were enrolled and 28 blood samples were analyzed. In 9 (60%) patients, at least one sample was positive for the presence of a KRAS exon 2 mutation. In 11 out of 28 samples (39.2%) with detectable CTCs a KRAS mutation was detected; the corresponding percentages for baseline and on progression samples were 27% and 37.5%, respectively. The most commonly detected mutations were G13D and G12C (n = 3). The presence of KRAS mutated CTCs at baseline was not prognostic for either PFS (P = .950) or OS (P = .383). CTC kinetics did not follow tumor response patterns. CONCLUSION: The results demonstrate that using a qPCR-based assay, KRAS exon 2 mutations could be detected in CTCs captured by the ISET system from patients with RAS WT primary tumors. However, the clinical relevance of these CTCs remains to be determined in future studies.  相似文献   

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描述了采自中国浙江九龙山的苔类植物一新种——毛茎合叶苔Scapania paraphyllia T.Cao,C.Gao,J.Sun&B.R.Zuo。该新种与腋毛合叶苔S.bolanderiAust.相近,两种皆具带齿叶片和假鳞毛,但新种具如下特征可与腋毛合叶苔区别:(1)植物体小,通常红色;(2)假鳞毛多数,不分枝,不仅生于叶腋,茎上也有着生;(3)背脊为腹瓣长的1/4-1/3,背瓣为腹瓣大小1/2-1/3;(4)叶角质层表面粗糙,具粗瘤,直径达6-8μm。与另一个相似种sampliata Steph.相比,因新种具有粗糙的叶表面和假鳞毛等特征,也易于区别。  相似文献   

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描述了中国云南姜科Zingiberaceae一新种——苍山象才参Roscoea cangshanensisM.H.LUO,X.F.Gao&H.H.Lin。该种与大理象牙参R.forrestii Cowley在体态上相近,但唇瓣深裂成2裂片,每个裂片再2裂,基部收缩成具白色条纹的柄,叶片较狭窄,(2-)7-24×1.5-2.5cm,叶片基部狭缩成叶柄状而不同。该新种叶片基部狭缩成叶柄状,唇瓣倒卵状楔形,长2.5-3.5cm,宽2.5-3.0cm,基部收缩成具白色条纹的柄,与长柄象牙参R.debilis Gagnep.相似,但苞片非管状,较短,长5-15mm,隐藏于叶鞘内,花冠管较长,10-12.5cm,唇瓣深裂成2裂片,每个裂片再2裂,可与后者明显区别。  相似文献   

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Microtubules and the organization of the Golgi complex   总被引:42,自引:0,他引:42  
Electron microscopic and cytochemical studies indicate that microtubules play an important role in the organization of the Golgi complex in mammalian cells. During interphase microtubules form a radiating pattern in the cytoplasm, originating from the pericentriolar region (microtubule-organizing centre). The stacks of Golgi cisternae and the associated secretory vesicles and lysosomes are arranged in a circumscribed juxtanuclear area, usually centered around the centrioles, and show a defined orientation in relation to the rough endoplasmic reticulum. Exposure of cells to drugs such as colchicine, vinblastine and nocodazole leads to disassembly of microtubules and disorganization of the Golgi complex, most typically a dispersion of its stacks of cisternae throughout the cytoplasm. These alterations are accompanied by disturbances in the intracellular transport, processing and release of secretory products as well as inhibition of endocytosis. The observations suggest that microtubules are partly responsible for the maintenance and functioning of the Golgi complex, possibly by arranging its stacks of cisternae three-dimensionally within the cell and in relation to other organelles and ensuring a normal flow of material into and away from them. During mitosis, microtubules disassemble (prophase) and a mitotic spindle is built up (metaphase) to take care of the subsequent separation of the chromosomes (anaphase). The breaking up of the microtubular cytoskeleton is followed by vesiculation of the rough endoplasmic reticulum and partial atrophy, as well as dispersion of the stacks of Golgi cisternae. After completion of the nuclear division (telophase), the radiating microtubule pattern is re-established and the rough endoplasmic reticulum and the Golgi complex resume their normal interphase structure. This sequence of events is believed to fulfil the double function to provide tubulin units and space for construction of the mitotic spindle and to guarantee an approximately equal distribution of the rough endoplasmic reticulum and the Golgi complex on the two daughter cells.  相似文献   

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The interaction of K+ with mammalian ribosomes was studied by equilibrium dialysis and compared with that of other univalent cations. The heavy K+ analogue, Tl+, binds more firmly than K+ to ribosomes and, unlike K+, has a practically useful isotope. With 204Tl+ as a marker of K+-selective binding the ribosome-cation interaction could be followed down to levels below 0.1 average Tl+-occupied site per ribosome. The Tl+/ribosome ratio varied with the free Tl+ concentration in a multiple way. At high Tl+ saturation Tl+ was easily displaced by Mg2+. With decreasing Tl+ saturation the competitive activity of Mg++ was strikingly reduced, indicating that Tl+ and Mg++ compete with different efficiency for different classes of sites.The experiments on univalent cations were performed at 1.5 mM Mg2+ under two complementary conditions: (1) Ribosomes were pretreated with 5 × 10?2, 5 × 10?3, and 5 × 10?4 M LiNO3, NaNO3, KNO3, and CsNO3, and then equilibrated with different concentrations of 204TlNO3 in the same buffers. (2) Ribosomes were pretreated with 10?2, 10?4, and 10?6 M 204TlNO3, and then equilibrated with different concentrations of LiNO3, NaNO3, KNO3, and CsNO3 (displacement experiments). At high Tl+ saturation Na+ and Li+ were about as active as K+ and Cs+ in competing with 204Tl+. With decreasing Tl+ saturation a differentiation occurred in favor of K+ and Cs+, with some preference for K+. It is concluded that ribosomes contain a limited number of sites with pronounced ion specificity. Of physiological cations K+ is most firmly bound to these sites.  相似文献   

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广西唇柱苣苔属(苦苣苔科)一新变种——光华唇柱苣苔   总被引:1,自引:0,他引:1  
记载了广西苦苣苔科Gesneriaceae一新变种——光华唇柱苣苔Chirita tribracteata、W.T.Wang var.zhuana Z.Y.Li,Q.Xing&Y.B.Li。该变种与原变种不同在于叶大而厚,边缘具圆齿或牙齿,叶柄具宽翅,苞片宽倒卵形或倒披针形,有锯齿,花冠淡紫色,喉部具黄色纵纹。  相似文献   

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中国云南秋海棠属(秋海棠科)一新种——假侧膜秋海棠   总被引:1,自引:0,他引:1  
描述了中国云南秋海棠科Begoniaceae秋海棠属Begonia扁果组sect.Platycentrum的一新种——假侧膜秋海棠Begonia coelocentroides Y.M.Shui&Z.D.Wei。该种与山地秋海棠B.oreodoxa Chun&F.Chun相似,子房上部为侧膜胎座,但雌花被片5,蒴果最大翅舌形,长20-22mm,而易于区别。  相似文献   

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Plagiochila dubia Lindenb. & Gottsche is reduced to a synonym of the Neotropical P. patula (Sw.) Lindenb. Specimens from the Canary Islands and Madeira proved to belong to the eastern North American P. virginica A.Evans, new to Europe. Phylogenetic analyses of the internal transcribed spacer regions (ITS1-5.8S-ITS2) of nuclear ribosomal DNA of ten Plagiochila species produced four independent lineages that are well supported by all bootstrap analyses (maximum likelihood, maximum parsimony, and distance). These lineages correspond with the Plagiochila sections Arrectae, Contiguae, Cucullatae and Glaucescentes. Spruce's “Ramiflorae” and “Cauliflorae” may no longer be regarded as monophyletic units of Plagiochila. Received August 19, 2001 Accepted October 11, 2001  相似文献   

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报道了在广西发现的2个百合科蜘蛛抱蛋属Aspidistra新种,即乳突蜘蛛抱蛋A. papillata G. Z. Li和环江蜘蛛抱蛋A. huanjiangensis G. Z. Li&Y. G. Wei。乳突蜘蛛抱蛋与大花蜘蛛抱蛋A. tonkinensis(Gagner. )F. T. Wang&K. Y. Lang近缘。它们的共同特征是:花单生;花被裂片两侧彼此覆盖;柱头盾状,边缘3裂,上表面具3条辐射状沟缝。不同点是:乳突蜘蛛抱蛋植株较大花蜘蛛抱蛋的粗大;叶柄较粗;叶片椭圆形或长椭圆形;花被阔钟  相似文献   

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描述了四川无心菜属(石竹科)一新种——道孚无心菜Arenaria dawuensis A. J. Li&Q. Ban。该种具纺锤形根,聚伞花序,花柱2,线形而与纟遂瓣无心菜A. fimbriata(E. Pritz. )Mattf. 相近,但叶匙形,萼片边缘具长缘毛,花瓣短于萼片,顶端细流苏状而不同。  相似文献   

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中国珍珠菜属(报春花科)一新种——右旋过路黄   总被引:1,自引:0,他引:1  
对新种右旋过路黄Lysimachia dextrorsiflora X. P. Zhang, X. H. Guo &; J. W. Shao进行了描述和绘图。该新种产于中国安徽和福建, 因茎匍匐, 叶对生, 花黄色, 单生叶腋与过路黄L. christinae Hance近缘, 但其花冠裂片在蕾期右旋(顺时针)旋转排列(俯视), 花梗通常长于叶片与叶柄长之和, 花期4月初至5月初而不同。  相似文献   

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云南龙血树属(龙舌兰科)一新种——深脉龙血树   总被引:1,自引:0,他引:1  
描述了龙血树属Dracaena一新种--深脉龙血树D. impressivenia Y. H. Yan &; H. J. Guo, 并绘了线图。该种产于中国云南盈江县, 与矮龙血树D. terniflora Roxb.叶形相似, 但侧脉深陷, 总状花序上具许多每6-9朵簇生的花, 苞片暗红色, 花被伸直, 长3-3.5 cm, 可与后者明显区别。  相似文献   

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报道了产于中国云南高黎贡山的水龙骨科Polypodiaceae节肢蕨属Arthromeris一新种——贯众叶节肢蕨A.cyrtomioides S.G Lu&C.D.Xu。该新种的植标大小与节肢蕨A .lehmanni(Mett.)Ching相似。但叶片的背面密被绒毛,表面被短柔毛,侧生羽片9-16对。该新种在毛被方面与厚毛羽毛节肢蕨A.tomentosa W.M.Chu相似,但羽片边缘无软骨质的膜质边,侧生羽片多达9-16对。  相似文献   

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