1株产紫杉醇内生真菌LNUF014的鉴定及产物检测

从红豆杉的韧皮部组织中分离得到的360株内生真菌中,通过对发酵粗提的检测,共筛选到11株产紫杉醇的真菌。其中1株内生真菌LNUF014的发酵液采用有机试剂抽提紫杉醇,经薄层层析和高效液相色谱分析,初步表明该菌株的紫杉醇类物质含量为53.68μg/L。根据形态学研究和真核生物18S rDNA基因序列分析,将其鉴定为镰刀菌属(Fusarium)。产紫杉醇内生真菌的研究将对紫杉醇类抗肿瘤药物的研制具有重要意义。     

贵州苏铁根的解剖学研究

对贵州苏铁（Cycas guizhouensis K.M.Lan et R.F.Zou）的根进行了解剖学研究,结果表明：（1）据外部形态和内部结构不同,贵州苏铁的根可分为正常根、珊瑚状根和肉质根三种类型。（2）正常根与肉质根的木栓形成层起源于表皮内方第1～2层皮层薄壁细胞,珊瑚状根的木栓形成层则起源于外方皮层的第2～3层细胞,而非中柱鞘。（3）首次发现肉质根一种新的增粗方式,是由周皮内方的皮层薄壁细胞恢复分裂能力,持续或周期性产生新的皮层薄壁细胞,引起根的增粗。     

高黎贡山地区雉类多样性及其保护

根据高黎贡山地形和气候变化,将其分为南、中、北三段。通过查阅文献、访谈和野外调查,在该地区共记录到21种雉类。分布在海拔2500m以上的仅有9种,占45%;在海拔2500m以下的地域分布有雉类17种,占85%。北段有雉类13种,中段有11种,南段有12种。其中北、中、南段均有分布的仅有3种,北段和中段共有种为9种,中段和南段共有种为5种,北段和南段共有种也是5种。结果表明雉类多样性随海拔升高而降低,北段高于南段。生境破坏与狩猎是该区雉类生存的主要威胁因子。加强管理,恢复和建立生境走廊,加强宣传教育和执法力度以及开展观鸟旅游,可使该区雉类得到更好的保护。     

Bacteriophages immunomodulate the response of monocytes

Bacteriophages are present in fluids from cirrhosis patients. However, their effect on the immune response is unknown. In this work, we explore the role of phages in the phenotype, function, and cytokine production of monocytes. We stimulated healthy monocytes with five different butanol-purified phage suspensions infective for Gram-negative and Gram-positive bacteria. We studied the expression of the monocyte markers involved in lipopolysaccharide recognition (LPS; CD14), antigen presentation (HLA-DR) and co-stimulation (CD86), and the concentration of induced cytokines (TNF-α, IFN-α, and IL-10) by phages. To confirm the direct role of phages without the interference of contaminating soluble LPS in phage suspensions, polymyxin B was added to the cell cultures. Phagocytosis experiments were assessed by flow cytometry using labeled phage suspensions. We observed that butanol-purified phages reduced the surface levels of CD14 and CD86 in monocytes and increased the secreted levels of TNF-α and IL-10 compared with the control sample containing only butanol buffer. All phage suspensions showed downregulation of HLA-DR expression but only Staphylococcus aureus phage contaminated with Escherichia coli reached statistical significance. The addition of polymyxin B did not restore the monocytic response induced by phages, suggesting that the effect was not caused by the presence of LPS. Monocytes were able to phagocyte phages in a dose- and time-dependent manner. To conclude, the phagocytosis of butanol-purified phages altered the phenotype and cytokine production of monocytes suggesting they become tolerogenic.     

Regeneration and characterization of somatic hybrids combining sweet orange and mandarin/mandarin hybrid cultivars for citrus scion improvement

Protoplast fusion between sweet orange and mandarin/mandarin hybrids scion cultivars was performed following the model ??diploid embryogenic callus protoplast?+?diploid mesophyll-derived protoplast??. Protoplasts were isolated from embryogenic calli of ??Pera?? and ??Westin?? sweet orange cultivars (Citrus sinensis) and from young leaves of ??Fremont??, Nules??, and ??Thomas?? mandarins (C. reticulata), and ??Nova?? tangelo [C. reticulata?×?(C. paradisi?×?C. reticulata)]. The regenerated plants were characterized based on their leaf morphology (thickness), ploidy level, and simple sequence repeat (SSR) molecular markers. Plants were successfully generated only when ??Pera?? sweet orange was used as the embryogenic parent. Fifteen plants were regenerated being 7 tetraploid and 8 diploid. Based on SSR molecular markers analyses all 7 tetraploid regenerated plants revealed to be allotetraploids (somatic hybrids), including 2 from the combination of ??Pera?? sweet orange?+???Fremont?? mandarin, 3 ??Pera?? sweet orange?+???Nules?? mandarin, and 2 ??Pera?? sweet orange?+???Nova?? tangelo, and all the diploid regenerated plants showed the ??Pera?? sweet orange marker profile. Somatic hybrids were inoculated with Alternaria alternata and no disease symptoms were detected 96?h post-inoculation. This hybrid material has the potential to be used as a tetraploid parent in interploid crosses for citrus scion breeding.     

Clinical Value of Prognosis Gene Expression Signatures in Colorectal Cancer: A Systematic Review

Introduction

The traditional staging system is inadequate to identify those patients with stage II colorectal cancer (CRC) at high risk of recurrence or with stage III CRC at low risk. A number of gene expression signatures to predict CRC prognosis have been proposed, but none is routinely used in the clinic. The aim of this work was to assess the prediction ability and potential clinical usefulness of these signatures in a series of independent datasets.

Methods

A literature review identified 31 gene expression signatures that used gene expression data to predict prognosis in CRC tissue. The search was based on the PubMed database and was restricted to papers published from January 2004 to December 2011. Eleven CRC gene expression datasets with outcome information were identified and downloaded from public repositories. Random Forest classifier was used to build predictors from the gene lists. Matthews correlation coefficient was chosen as a measure of classification accuracy and its associated p-value was used to assess association with prognosis. For clinical usefulness evaluation, positive and negative post-tests probabilities were computed in stage II and III samples.

Results

Five gene signatures showed significant association with prognosis and provided reasonable prediction accuracy in their own training datasets. Nevertheless, all signatures showed low reproducibility in independent data. Stratified analyses by stage or microsatellite instability status showed significant association but limited discrimination ability, especially in stage II tumors. From a clinical perspective, the most predictive signatures showed a minor but significant improvement over the classical staging system.

Conclusions

The published signatures show low prediction accuracy but moderate clinical usefulness. Although gene expression data may inform prognosis, better strategies for signature validation are needed to encourage their widespread use in the clinic.     

Muscle damage and its relationship with muscle fatigue during a half-iron triathlon

Background

To investigate the cause/s of muscle fatigue experienced during a half-iron distance triathlon.

Methodology/Principal Findings

We recruited 25 trained triathletes (36±7 yr; 75.1±9.8 kg) for the study. Before and just after the race, jump height and leg muscle power output were measured during a countermovement jump on a force platform to determine leg muscle fatigue. Body weight, handgrip maximal force and blood and urine samples were also obtained before and after the race. Blood myoglobin and creatine kinase concentrations were determined as markers of muscle damage.

Results

Jump height (from 30.3±5.0 to 23.4±6.4 cm; P<0.05) and leg power output (from 25.6±2.9 to 20.7±4.6 W · kg⁻¹; P<0.05) were significantly reduced after the race. However, handgrip maximal force was unaffected by the race (430±59 to 430±62 N). Mean dehydration after the race was 2.3±1.2% with high inter-individual variability in the responses. Blood myoglobin and creatine kinase concentration increased to 516±248 µg · L⁻¹ and 442±204 U · L⁻¹, respectively (P<0.05) after the race. Pre- to post-race jump change did not correlate with dehydration (r = 0.16; P>0.05) but significantly correlated with myoglobin concentration (r = 0.65; P<0.001) and creatine kinase concentration (r = 0.54; P<0.001).

Conclusions/significance

During a half-iron distance triathlon, the capacity of leg muscles to produce force was notably diminished while arm muscle force output remained unaffected. Leg muscle fatigue was correlated with blood markers of muscle damage suggesting that muscle breakdown is one of the most relevant sources of muscle fatigue during a triathlon.     

大花栀子植物挥发物成分测定及其日变化分析

为探究大花栀子植物挥发物成分组成及其一天内早、中、晚的差异,采用热脱附气质联用技术对其进行香气成分的分析。结果表明:全天从其花朵中共鉴定出62种成分,主要为萜烯类、酯类、醇类物质,且不同时间其成分差异显著,如早、中、晚3个时间段,β-蒎烯相对含量分别为1.93%、1.69%、8.81%,顺式-β-罗勒烯分别为28.22%、4.35%、16.47%。3-蒈烯(3.45%)、异丁子香酚(0.21%)等只在早上检出;月桂烯(0.38%)、伞花烃(2.46%)等只在晚上检出;芳樟醇、金合欢烯等在早上和午间两个时间段相对含量较高,而在晚上却未检测出。从植物VOCs角度结合其日变化动态,为大花栀子园林配置及其综合开发利用提供理论依据。     

早熟油菜成花相关基因LFY的克隆与分析

以甘蓝型油菜晚熟品种RG-8的早熟突变体RG-8M为材料,通过同源克隆法得到1个LEAFY(LFY)同源基因,命名为BnLFY。该基因cDNA全长为1 310bp,包含1个长为1 248bp的开放阅读框,编码415个氨基酸。序列分析表明,推测的氨基酸序列含双子叶植物LFY类蛋白特有的N端脯氨酸富集区、中央酸性区、亮氨酸拉链结构以及富含赖氨酸与精氨酸的碱性区;且与几种十字花科植物LFY类蛋白的氨基酸序列一致性均在84%以上。转录表达分析表明,BnLFY基因在油菜中为组成型表达。