AHR,a novel acute hypoxia‐response sequence,drives reporter gene expression under hypoxia in vitro and in vivo

ADAMTS1 (a disintegrin and metalloproteinase with thrombospondin motifs 1) is an early immediate gene. We have previously reported that ADAMTS1 was strongly induced by hypoxia. In this study, we investigated whether ADAMTS1 promoter‐driven reporter signal is detectable by acute hypoxia. We constructed the GFP (green fluorescent protein) expression vector [AHR (acute hypoxia‐response sequence)‐GFP] under the control of ADAMTS1 promoter and compared it with the constitutive GFP‐expressing vector under the control of CMV (cytomegalovirus promoter‐GFP). We transduced AHR‐GFP and examined whether GFP signals can be detected under the acute hypoxia. When the human umbilical vein [HUVEC (human umbilical vein endothelial cells)] was transduced under normoxia, there were few GFP signals, while CMV‐GFP showed considerable GFP signals. When HUVEC was stimulated with hypoxia, GFP signals from AHR‐GFP gene were induced under hypoxic conditions. Notably, the GFP signals peaked at 3 h under hypoxia. In ischaemic hind limb model, transduced AHR‐GFP showed hypoxic induction of GFP signals. In summary, we have demonstrated that the AHR system induced the reporter gene expression by acute hypoxia, and its induction is transient. This is the first report showing the unique acute hypoxia‐activated gene expression system.     

Outer membrane vesicles of Porphyromonas gingivalis elicit a mucosal immune response

We previously reported that mutation of galE in Porphyromonas gingivalis has pleiotropic effects, including a truncated lipopolysaccharide (LPS) O-antigen and deglycosylation of the outer membrane protein OMP85 homolog. In the present study, further analysis of the galE mutant revealed that it produced little or no outer membrane vesicles (OMVs). Using three mouse antisera raised against whole cells of the P. gingivalis wild type strain, we performed ELISAs to examine the reactivity of these antisera with whole cells of the wild type or the galE mutant. All three antisera had significantly lower reactivity against the galE mutant compared to wild type. OMVs, but not LPS, retained the immunodominant determinant of P. gingivalis, as determined by ELISAs (with wild type LPS or OMVs as antigen) and absorption assays. In addition, we assessed the capacity of OMVs as a vaccine antigen by intranasal immunization to BALB/c mice. Synthetic double-stranded RNA polyriboinosinic polyribocytidylic acid [Poly (I∶C)], an agonist of Toll-like receptor 3 (TLR3), was used as the mucosal adjuvant. Vaccination with OMV elicited dramatically high levels of P. gingivalis-specific IgA in nasal washes and saliva, as well as serum IgG and IgA. In conclusion, the OMVs of P. gingivalis have an important role in mucosal immunogenicity as well as in antigenicity. We propose that P. gingivalis OMV is an intriguing immunogen for development of a periodontal disease vaccine.     

Two thimet oligopeptidase-like Pz peptidases produced by a collagen-degrading thermophile, Geobacillus collagenovorans MO-1

A collagen-degrading thermophile, Geobacillus collagenovorans MO-1, was found to produce two metallopeptidases that hydrolyze the synthetic substrate 4-phenylazobenzyloxycarbonyl-Pro-Leu-Gly-Pro-D-Arg (Pz-PLGPR), containing the collagen-specific sequence -Gly-Pro-X-. The peptidases, named Pz peptidases A and B, were purified to homogeneity and confirmed to hydrolyze collagen-derived oligopeptides but not collagen itself, indicating that Pz peptidases A and B contribute to collagen degradation in collaboration with a collagenolytic protease in G. collagenovorans MO-1. There were many similarities between Pz peptidases A and B in their catalytic properties; however, they had different molecular masses and shared no antigenic groups against the respective antibodies. Their primary structures clarified from the cloned genes showed lower identity (22%). From homology analysis for proteolytic enzymes in the database, the two Pz peptidases belong to the M3B family. In addition, Pz peptidases A and B shared high identities of over 70% with unassigned peptidases and oligopeptidase F-like peptidases of the M3B family, respectively. Those homologue proteins are putative in the genome database but form two distinct segments, including Pz peptidases A and B, in the phylogenic tree. Mammalian thimet oligopeptidases, which were previously thought to participate in collagen degradation and share catalytic identities with Pz peptidases, were found to have lower identities in the overall primary sequence with Pz peptidases A and B but a significant resemblance in the vicinity of the catalytic site.     

钛合金和钴铬合金表面白色念珠菌粘附的研究

目的比较钛合金(Ti-6Al-4V)和钴铬合金(Chromium-Cobaltalloy)表面白色念珠菌粘附能力的大小,研究表面粗糙度与细菌粘附的关系。方法将不同表面粗糙度的钛合金和钴铬合金试件进行白色念珠菌体外粘附试验,采用菌落形成计数法测定试件表面的细菌粘附量。结果各钛合金试件组的细菌粘附量均少于相同表面粗糙度的钴铬合金试件组,两种金属试件表面的细菌粘附量均随表面粗糙度的增大而增加。结论钛合金较钴铬合金更能减少由白色念珠菌引起的义齿性口炎等并发症,同时修复体表面严格的研磨抛光也能有效减少这些并发症。     

毒品快速定量测试方法的探讨

阐述了毒品金免疫层析试条的定量测试机理,推导出浓度值与吸光度之间的测试模型,并对主要干扰因素及消除方法进行分析。最后验证了毒品快速定量测试方法的可行性。     

小鼠雌性生殖系统电穿孔与微泡增强超声波转EG即基因的研究（简报）

非病毒载体转基因法。如注射裸DNA或脂质体转染,不产生细胞毒性。但除了肌肉组织外其他组织的转导效率均不高。电脉冲可使细胞膜产生临时的微孔允许一些分子通过。因此应用此方法可将药物或基因转人动物组织。电穿孔常用于培养的细胞转基因,理论上,低强度、长脉冲。或高强度、短脉冲有利于电转导。选择适合的参数是电转导的关键。本实验比较了不同电压和脉冲时间对小鼠卵巢在体转入绿色荧光蛋白基因的效果．确定了最适的电转导参数。为卵巢疾病的药物、基因治疗和研究卵泡发育中的基因调控提供了实验手段。     

渤海莱州湾表层沉积物中底栖有孔虫分布特征及其环境意义

对渤海莱州湾海域240个站位表层沉积物中底栖有孔虫群落进行了分析,共鉴定常见的底栖有孔虫42种。结果表明,莱州湾表层沉积物中底栖有孔虫主要以玻璃质壳为主(平均丰度达70.9%),瓷质壳含量次之,胶结壳含量最低;玻璃质壳占有孔虫全群的百分含量,随水深的增加而增加;从黄河口向外海方向,有孔虫分异度和丰度都逐渐增大。该海域底栖有孔虫平面分布的主要控制因素为盐度和底质沉积物类型,大体可分为两个组合分区,I区为Ammonia beccarii-Quinqueloculina spp.组合,代表盐度较低的近岸海陆过渡浅水环境;II区为Cribrononionsub-incertum-Protelphidium tuberculatum组合,代表盐度较高的远岸内陆架环境。     

甘肃窑街侏罗纪Pityostrobus sp.的原位花粉与分散花粉的关系

松柏类植物是侏罗纪最为繁盛的裸子植物类群之一。通过室内实验和镜下鉴定,对甘肃窑街盆地中侏罗世Pityostrobus sp.的原位花粉进行了研究,并结合现生松科花粉的形态特征,分析对比了其原位花粉与地层中的分散花粉的关系,经对比分析,初步认为Piceites arxanensis是化石Pityostrobus sp.的花粉,而后者是前者的母体植物。化石Pityostrobus sp.的原位花粉特征的研究,对古松柏类化石植物的鉴定和分类具有一定的指导意义;同时,可为进一步研究古松柏类植物在中生代侏罗纪的地理分布和生态特征提供新的线索。     

北部湾中部海域底质沉积物中的有孔虫

本文对北部湾中部海域水深2.4m到61m、共计184个站位表层沉积物中的有孔虫进行研究。结果显示浮游有孔虫丰度非常低,种类也较稀少,仅在南侧水深较大的少数站位有发现,且含量不超过5%;而底栖有孔虫则较丰富,多数样品中以含有螺旋式与平旋式的玻璃质壳类型为主,暖水或大型底栖有孔虫分子常见。和其它海区相较而言,该海域底栖有孔虫中胶结壳类含量偏高,可能与沉积物底质颗粒较粗及海水盐度较低有关。该研究详细报道了底栖有孔虫主要属种在北部湾的分布特征。与海洋环境对比显示,水深和沉积物底质类型是影响这些属种平面分布的主要因素,而湾外温暖水团则是控制暖水种分子分布的另一重要因素。