Proteomic Analysis of High Temperature Stress-Responsive Proteins in Chrysanthemum Leaves

Chrysanthemum is one of the most important ornamental flowers in the world, and temperature has a significant influence on its field production. In the present study, differentially expressed proteins were investigated in the leaves of Dendranthema grandiflorum ‘Jinba’ under high temperature stress using label-free quantitative proteomics techniques. The expressed proteins were comparatively identified and analyzed. A total of 1,463 heat-related, differentially expressed proteins were successfully identified by Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS), and 1,463 heat-related, differentially expressed proteins were successfully identified by mass spectrometry after a high temperature treatment. Among these, 701 proteins were upregulated and 762 proteins were downregulated. The in-depth bioinformatics analysis of these differentially expressed proteins revealed that these were involved in energy metabolism pathways, protein metabolism, and heat shock. In the present study, the investigators determined the changes in the levels of some proteins, and their expression at the protein and molecular levels in chrysanthemum to help reveal the mechanism of heat resistance in chrysanthemum. Furthermore, the present study elucidated some of the proteins correlated to heat resistance in chrysanthemum, and their expression changes at the protein and molecular levels to help reveal the mechanism of heat resistance in this flower species. These results provide a theoretical basis for the selection of new heat resistant varieties of chrysanthemum in the field.     

Proteasome Inhibition-Induced Downregulation of Akt/GSK-3β Pathway Contributes to Abnormality of Tau in Hippocampal Slice

Proteasome inhibition can induce abnormal accumulation and phosphorylation of microtubule-associated protein tau. The major function of tau protein is to promote microtubules assembly and stabilization, and abnormal tau protein would disturb its microtubule-binding function. In this study, proteasome inhibitor MG132 was used to treat hippocampal slices to explore the role and mechanism of Akt/glycogen synthase kinase-3β (GSK-3β) in proteasome inhibition-induced tau abnormality. During the culture period, we measure the lactate dehydrogenase (LDH) content to assay the viability of hippocampal slices. Following 2.5 and 5 μM MG132 treatment for 6 h, we detected the expression, phosphorylation modification, and microtubule-binding function of tau protein of slices. We also analyzed the changed activities of glycogen synthase kinase-3β (GSK-3β) and protein kinase B (PKB/Akt) and the level of heat shock protein 90 (Hsp90) in the process. In addition, co-immunoprecipitation was used to investigate the interaction between Akt and Hsp90, Akt and protein phosphatase-2A (PP2A) in the MG132-treated organotypic hippocampal slices. Our results indicated that proteasome inhibition led to degradation obstacles and abnormal phosphorylation of tau protein. The downregulated Akt/GSK-3β signaling pathway might be responsible for the abnormal phosphorylation of tau protein at multiple sites which further reduced the microtubule-binding function of tau protein. Furthermore, proteasome inhibition decreased the binding capacity of Akt-Hsp90 while increased the Akt-PP2A binding ability which mediated Akt inactivity. This current study establishes a hippocampal slice model targeting Akt/GSK-3β signaling pathway to explore the pivotal role of proteasome inhibition in tau pathology.     

Risk Factors of Pneumothorax after Endobronchial Ultrasound-Guided Transbronchial Biopsy for Peripheral Lung Lesions

Background

The risk of endobronchial ultrasound-guided transbronchial biopsy-related pneumothorax is a major concern and warrants further studies. The aim of our study was to estimate the risk of pneumothorax after this procedure and identify its risk factors.

Methods

From 2007 to 2011, 399 patients who underwent endobronchial ultrasound-guided transbronchial biopsy for peripheral lung lesions were included in this study. The variables analyzed included patient factors, lesion factors and procedure factors. Multivariate logistic regression analysis was used to identify independent risk factors for pneumothorax.

Results

The incidence of pneumothorax was 3.3% (13/399). Chest tube placement was required for 31% (4/13) of pneumothoraces. Independent risk factors for pneumothorax included pulmonary emphysema (OR, 55.09; 95% CI, 9.37–324.03; p<0.001) and probe position adjacent to the lesion (OR, 17.01; 95% CI, 2.85–101.64; p = 0.002). The number of biopsy specimens, age, sex, history of prior lung surgery and lesion size, location and character did not influence the risk of pneumothorax in our analyses.

Conclusions

The risk of pneumothorax after endobronchial ultrasound-guided transbronchial biopsy is low. To further reduce the risk of pneumothorax, every effort should be made to advance the endobronchial ultrasound probe into the bronchus where it is imaged within the target lesion before embarking on transbronchial biopsy.     

兰花蕉花部维管束系统的解剖学研究

兰花蕉花梗的维管束分散排列．子房基部的维管束排成两部分,外方为一轮大维管束环,中央为分散排列的小维管束区。前者的纸管束进入子房壁,后者进入子房的中轴,形成股座纸管束;及至延长都以后,股座维管束逐渐消失．子房壁上的维管束较易识别的有心皮背束、心皮背束伴束和隔膜束．三束心皮背束经延长部最终进入花柱和柱头．心皮背束指心皮背束务与其紧靠的大维管束,三枚心皮背束伴束最终分别进入三枚外轮雄蓝．三枚隔膜束中远轴面的两枚分别进入两校内轮雄蕊,而近轴面的一枚伴随着第六枚雄蓝的缺失最后进入唇瓣中央．子房壁其余的维管束进入延长部后,先向外分出一轮纸管束进入花幕,余下的中央部分排成一轮心形的线管来环．该环远轴面的维管束分为两半分别进入两枚侧生花瓣;近轴面即心形凹陷一侧初为两轮即外轮大的维管束与内轮小的维管束,后排成一轮并与近轴面的隔膜束一同进入唇瓣．兰花蕉的唇瓣既为花瓣成员,又含一枚缺失的雄蓝维管束,与姜目已报道的只来自退化雄蕊的竹芋科的兜状结构和美人蕉科、姜科、闭鞘姜科的唇瓣有明显区别．在旅人蕉科尚未有研究资料的情况下,作者根据已有资料,对姜目雄蕊维管束系统来源和结构进行比较,初步认为在姜目的系统演化上,兰花蕉科与芭蕉料更近．     

生物复苏——大绝灭后生物演化历史的第一幕

生命史是一部生物界短期,快速剧变与长期,慢速稳定相互交替的历史。大绝灭（即集群绝灭）事件反映了全球环境的大突变,点断了地质历史中的生命记录及其发展历程,预示着生物界的演化出现了最有意义的飞跃,近年来尝试研究大绝灭后全球生物界的残存－复苏及其基本型式,并探索复苏的控制因素,标志着地质科学中一个重心的转移（即从大绝灭转向其后的生物残存与复苏的研究）。生物复苏揭示了大绝灭后生物演化历史的第一幕,其研究的     

青海湖裸鲤寄生舌状绦虫的空间格局研究

舌状绦虫裂头蚴只寄生在体长小于２２０ｍｍ的青海湖裸鲤中,其种群在宿主种群中呈聚集分布。其聚集分布的强度随寄生虫种群平均密度的增加而降低。由于舌状绦虫在宿主体腔生长,产生明显的空间拥挤效应,可能导致宿主死亡或被食鱼鸟类捕食而转移到终末宿主中。在体长小于１２０ｍｍ的宿主中,密度依赖的死亡过程可能是使聚集强度降低的原因;而体长１４０－２００ｍｍ的鱼中,则是非密度依赖的全死过程使聚集强度增加．     

Immunochemical studies on blood groups: The internal structure and immunological properties of water-soluble human blood group A substance studied by Smith degradation,liberation, and fractionation of oligosaccharides and reaction with lectins

Carbohydrate structures in the interior of a blood group A active substance (MSS) were exposed by one and by two Smith degradations. Reactivities of the original glycoprotein and its Smith degraded products with 13 different lectins and with anti-I Ma were studied by quantitative precipitin assay. MSS and its first Smith degraded product completely precipitated Ricinus communis hemagglutinin with five times less of the first Smith degraded glycoprotein being required for 50% precipitation. The second Smith degraded material precipitated only 90% of the lectin. MSS did not precipitate peanut lectin, whereas its first and second Smith degraded products completely precipitated the lectin. The first Smith degraded glycoprotein also reacted well with Wistaria floribunda, Maclura pomifera, Bauhinia purpurea alba, and Geodia lectins indicating that its carbohydrate moiety could contain dGalNAc, dGalβ1 → 3dGalNAc, dGalβ1 → 4dGlcNAc, dGalβ1 → 3dGlcNAcβ1 → 3dGal and/or dGalβ1 → 4dGlcNAcβ1 → 6dGal and/or dGalβ1 → 4dGlcNAcβ1 → 6dGalNAc determinants at nonreducing ends. The second Smith degraded material precipitated well with Ricinus communis hemagglutinin, Arachis hypogaea, Geodia cydonium, Maclura pomifera, and Helix pomatia lectins showing that dGalNAc, dGalβ1 → 3dGalNAc, dGalβ1 → 4dGlcNAc residues at terminal nonreducing ends could be involved. Monoclonal anti-I Ma (group 1) serum reacted strongly with the first Smith degraded product indicating large numbers of anti-I Ma determinants, dGalβ1 → 4dGlcNAcβ1 → d 6dGal and/or dGalβ1 → 4dGlcNAcβ1 → 6dGalNAc at nonreducing ends. The comparable activities of the native and Smith degraded products with wheat germ lectin indicate capacity to react with DGlcNAc residues at nonreducing ends and/or at positions in the interior of the chain. The totality of lectin reactivities indicates heterogeneity of the carbohydrate side chains. Oligosaccharides with ³H at their reducing ends released from the protein core of the first and second Smith degraded products were obtained by treatment with 0.05 m NaOH and 1 M NaB³H₄ at 50 °C for 16 h (Carlson degradation). The liberated reduced oligosaccharides were fractionated by dialysis, followed by retardion, Bio-Gel P-2, P-4, and P-6 columns. They were further purified on charcoal-celite columns, and by preparative paper chromatography and high-pressure liquid chromatography. Their distribution by size was estimated by the yields on dialysis, Bio-Gel P-2, and Bio-Gel P-6 chromatography, and from the radioactivity of the reduced sugars. Of the oligosaccharide fractions from the first Smith degraded product, about 77% of the carbohydrate side chain residues contained from 1 to 6 sugars, 13% from 7 to perhaps 12 sugars, and 10% was nondialyzable (polysaccharides and glycopeptide fragments). Of the second Smith degraded product, approximately 82% of carbohydrate residues had from 1 to 6 sugars, 14% from 7 to perhaps 20 sugars and 4% was nondialyzable. The biological activity profile of the two Smith degraded products together with the size distributions of the oligosaccharides indicated that their carbohydrate side chains, comprised a heterogeneous population ranging in size from 1 to about 12 sugars. When most of these chains that are shorter than hexasaccharides are fully characterized it may be possible to reconstruct the overall structure of the carbohydrate moiety of the blood group substances and account for their biological activities.     

Complete genome sequence of an H10N8 avian influenza virus isolated from a live bird market in Southern China

An H10N8 avian influenza virus (AIV), designated A/Duck/Guangdong/E1/2012 (H10N8), was isolated from a duck in January 2012. This is first report that this subtype of AIV was isolated from a live bird market (LBM) in Guangdong Province in southern China. Furthermore, the complete genome of this strain was analyzed. The availability of genome sequences is helpful to further investigations of epidemiology and molecular characteristics of AIV in southern China.