Lack of Interleukin-6 (IL-6) Enhances Susceptibility to Infection but Does Not Alter Latency or Reactivation of Herpes Simplex Virus Type 1 in IL-6 Knockout Mice

The ability of the pleotropic, proinflammatory cytokine interleukin-6 (IL-6) to affect the replication, latency, and reactivation of herpes simplex virus type 1 (HSV-1) in cell culture and in IL-6 knockout (KO) mice was studied. In initial studies, we found no effect of exogenous IL-6, monoclonal antibodies to IL-6, or monoclonal antibody to the IL-6 coreceptor, gp130, on HSV-1 replication in vitro by plaque assay or reactivation ex vivo by explant cocultivation of latently infected murine trigeminal ganglia (TG). Compared with the wild-type (WT) mice, the IL-6 KO mice were less able to survive an ocular challenge with 10(5) PFU of HSV-1 (McKrae) (40% survival of WT and 7% survival KO mice; P = 0.01). There was a sixfold higher 50% lethal dose of HSV-1 in WT than IL-6 KO mice (1.7 x 10(4) and 2.7 x 10(3) PFU, respectively). No differences were observed in titers of virus recovered from the eyes, TG, or brains or in the rates of virus reactivation by explant cocultivation of TG from latently infected WT or KO mice. Exposure of latently infected mice to UV light resulted in comparable rates of reactivation and in the proportions of WT and KO animals experiencing reactivation. Moreover, quantitative PCR assays showed nearly identical numbers of HSV-1 genomes in latently infected WT and IL-6 KO mice. These studies indicate that while IL-6 plays a role in the protection of mice from lethal HSV infection, it does not substantively influence HSV replication, spread to the nervous system, establishment of latency, or reactivation.     

东北小鲵中枢神经系统形态学与组织学初步研究

本文应用脊椎动物神经标本制作法和HE染色法,对东北小鲵中枢神经系统的外部形态和组织学结构进行了初步研究,描述了东北小鲵神经系统形态和组织学结构的特点,并与无尾两栖类和爬行类相对比,探讨了有尾两栖类的进化地位。结果表明:与无尾两栖类(如蛙)相比,东北小鲵中枢神经系统中,大脑半球较小,结构较为原始,小脑结构简单,是两栖类中较为原始的类群。此外,东北小鲵开始具有了臂神经丛和骶神经丛,但没有爬行类的发达,可作为两栖类向爬行类进化的证据之一。     

不同种源中间锦鸡儿碳氮磷化学计量特征研究

中间锦鸡儿(Caragana liouana)是中国毛乌素沙地的主要灌木建群种,在其主要分布区采集9个不同地理种源的种子,栽种至同质园,并测定不同器官(根、茎、叶)碳(C)、氮(N)、磷(P)含量,比较种源和器官间碳氮磷化学计量特征的差异及元素之间的相关性。结果显示:(1)不同种源中间锦鸡儿根、茎、叶的C含量差异显著,分别为361.12~426.30mg·g~(-1)、412.32~463.13mg·g~(-1)、419.21~478.94mg·g~(-1);N含量种源间差异显著,分别为20.52~33.67mg·g~(-1)、15.77~23.92mg·g~(-1)、27.60~36.44mg·g~(-1);P含量种源间差异显著,分别为1.52~3.73mg·g~(-1)、1.24~2.14mg·g~(-1)、1.44~2.38mg·g~(-1);不同器官的C/N、C/P、N/P也表现出种源间显著差异。(2)种源和器官对中间锦鸡儿碳氮磷化学计量特征的影响程度存在差异,种源对P、C/P、N/P影响较大,器官对C、N、C/N影响较大。(3)相关性分析表明,N、P分别对C/N和C/P的变异起主导作用,并共同影响N/P的变异。研究表明,中间锦鸡儿的碳氮磷化学计量特征在长期的适应进化过程中已产生遗传分化,并形成了自身的养分利用策略。     

Detection of Airborne Stachybotrys chartarum Macrocyclic Trichothecene Mycotoxins in the Indoor Environment

The existence of airborne mycotoxins in mold-contaminated buildings has long been hypothesized to be a potential occupant health risk. However, little work has been done to demonstrate the presence of these compounds in such environments. The presence of airborne macrocyclic trichothecene mycotoxins in indoor environments with known Stachybotrys chartarum contamination was therefore investigated. In seven buildings, air was collected using a high-volume liquid impaction bioaerosol sampler (SpinCon PAS 450-10) under static or disturbed conditions. An additional building was sampled using an Andersen GPS-1 PUF sampler modified to separate and collect particulates smaller than conidia. Four control buildings (i.e., no detectable S. chartarum growth or history of water damage) and outdoor air were also tested. Samples were analyzed using a macrocyclic trichothecene-specific enzyme-linked immunosorbent assay (ELISA). ELISA specificity was tested using phosphate-buffered saline extracts of the fungal genera Aspergillus, Chaetomium, Cladosporium, Fusarium, Memnoniella, Penicillium, Rhizopus, and Trichoderma, five Stachybotrys strains, and the indoor air allergens Can f 1, Der p 1, and Fel d 1. For test buildings, the results showed that detectable toxin concentrations increased with the sampling time and short periods of air disturbance. Trichothecene values ranged from <10 to >1,300 pg/m³ of sampled air. The control environments demonstrated statistically significantly (P < 0.001) lower levels of airborne trichothecenes. ELISA specificity experiments demonstrated a high specificity for the trichothecene-producing strain of S. chartarum. Our data indicate that airborne macrocyclic trichothecenes can exist in Stachybotrys-contaminated buildings, and this should be taken into consideration in future indoor air quality investigations.     

Interaction of epithelial cell membrane rafts with Paracoccidioides brasiliensis leads to fungal adhesion and Src-family kinase activation

Membrane rafts are cholesterol- and sphingolipid-enriched cell membrane domains, which are ubiquitous in mammals and play an essential role in different cellular functions, including host cell-pathogen interaction. In this work, by using several approaches, we demonstrated the involvement of epithelial cell membrane rafts in adhesion process of the pathogenic fungus Paracoccidioides brasiliensis. This conclusion was supported by the localization of ganglioside GM1, a membrane raft marker, at P. brasiliensis-epithelial cell contact sites, and by the inhibition of this fungus adhesion to host cells pre-treated with cholesterol-extractor (methyl-beta-cyclodextrin, MbetaCD) or -binding (nystatin) agents. In addition, at a very early stage of P. brasiliensis-A549 cell interaction, this fungus promoted activation of Src-family kinases (SFKs) and extracellular signal-regulated kinase 1/2 (ERK1/2) of these epithelial cells. Whereas SFKs were partially responsible for activation of ERK1/2, membrane raft disruption with MbetaCD in A549 cells led to total inhibition of SFK activation. Taking together, these data indicate for the first time that epithelial cell membrane rafts are essential for P. brasiliensis adhesion and activation of cell signaling molecules.     

基于Voronoi图的丹顶鹤巢址空间格局分析

依据1996年、2003—2007年扎龙保护区丹顶鹤巢址数据,利用Voronoi图理论,分析了巢址的空间分布特征,计算了其拓扑指数—Voronoi图面积。结果表明,丹顶鹤巢址空间分布具有明显的空间聚类特征。以扎龙保护区的2006年巢址、居民点、国道和铁路为对象,构成其Voronoi图,较好地说明了人类活动对丹顶鹤巢址的空间格局的影响,研究结果对丹顶鹤栖息地的保护将起到重要作用。     

植物丝氨酸/精氨酸丰富(SR)蛋白的结构和功能及其在植物发育中的作用

丝氨酸／精氨酸丰富（SR）蛋白家族是真核生物中的一类剪接因子,在前体mRNA的组成性和选择性剪接中起作用。本文就近十几年来SR蛋白结构和功能及其在植物发育中的作用的研究进展作以介绍。