双歧杆菌脂磷壁酸与5-氟尿嘧啶联用的抗肿瘤研究

目的探讨双歧杆菌脂磷壁酸与5-氟尿嘧啶（5-Fu）联用对H22荷瘤小鼠的抗肿瘤作用及免疫功能的影响。方法双歧杆菌脂磷壁酸单独或联合5-Fu处理H22荷瘤Balb／c小鼠,定期测量肿瘤大小,观察小鼠一般状况;计算抑瘤率、血红细胞数和白细胞数,取脾和胸腺计算脏器指数;HE染色分析肿瘤组织变化;MTT法检测小鼠脾T淋巴细胞增殖转化功能以及ELISA法检测小鼠脾淋巴细胞分泌IFN-γ含量。结果双歧杆菌脂磷壁酸及5-Fu单独应用均可抑制肿瘤生长,但单独5-Fu处理组小鼠一般状况差,毒性反应重;双歧杆菌脂磷壁酸与5-Fu联合应用,与单独5-Fu处理组比较,不仅抑瘤率明显提高（P〈0．01）,且荷瘤小鼠一般状况改善,白细胞数升高,脏器指数增加,小鼠脾T淋巴细胞增殖能力强,脾淋巴细胞分泌IFN-γ,水平提高;光镜观察HE染色瘤体组织,双歧杆菌脂磷壁酸处理组可见大量炎症细胞浸润。结论双歧杆菌脂磷壁酸联合5-FU能增强化疗的抑瘤作用,并能扭转化疗引起的免疫低下现象,起到增效减毒作用。     

‘中新4’杨树夏季光合生理特性研究

研究了南方杨树主栽品种'中新4'(Populus deltoides CL.'Zhongxin 4')幼株在6、7月两种不同生态条件下的光合生理特性.结果表明,高温(≥32℃)初期的净光合速率下降以气孔限制因素为主导;随高温时间延长和RH(相对湿度)降低,气孔及非气孔限制同时作用.'中新4'对高温胁迫的耐受程度随RH的不同而变化,RH降低,温度胁迫程度加大,表现量子效率下降.在空气湿润条件下,Pn(净光合速率)与PAR(叶片光合有效辐射)呈正相关;而在空气干燥的条件下,Pn与RH呈正相关.     

Arsenic upregulates MMP-9 and inhibits wound repair in human airway epithelial cells

As part of the innate immune defense, the polarized conducting lung epithelium acts as a barrier to keep particulates carried in respiration from underlying tissue. Arsenic is a metalloid toxicant that can affect the lung via inhalation or ingestion. We have recently shown that chronic exposure of mice or humans to arsenic (10-50 ppb) in drinking water alters bronchiolar lavage or sputum proteins consistent with reduced epithelial cell migration and wound repair in the airway. In this report, we used an in vitro model to examine effects of acute exposure of arsenic (15-290 ppb) on conducting airway lung epithelium. We found that arsenic at concentrations as low as 30 ppb inhibits reformation of the epithelial monolayer following scrape wounds of monolayer cultures. In an effort to understand functional contributions to epithelial wound repair altered by arsenic, we showed that acute arsenic exposure increases activity and expression of matrix metalloproteinase (MMP)-9, an important protease in lung function. Furthermore, inhibition of MMP-9 in arsenic-treated cells improved wound repair. We propose that arsenic in the airway can alter the airway epithelial barrier by restricting proper wound repair in part through the upregulation of MMP-9 by lung epithelial cells.     

Identification and characterization of ten polymorphic microsatellite loci in the red panda Ailurus fulgens

Ten polymorphic microsatellite loci were characterized from two genomic DNA-enriched libraries of the red panda (Ailurus fulgens). The number of observed alleles among 35 samples of red pandas ranged from five to 12. Observed and expected heterozygosities were 0.286–0.971 and 0.443–0.894, and the mean polymorphic information content was 0.712. All loci followed Hardy–Weinberg expectations except Aifu-14 and Aifu-16, which may due to the presence of inbreeding or null alleles. Three pairs of loci exhibited significant linkage disequilibrium after Bonferroni correction for multiple comparisons. These microsatellites would be useful to strengthen population management, genetic diversity exploration, and demographic history speculation of this species.     

瞬时感受器电位通道与疾病

哺乳动物瞬时感受器电位(transient receptor potential,TRP)通道超家族由TRPC、TRPM、TRPV、TRPA、TRPP和TRPML六个亚家族组成。这些亚家族的29个离子通道几乎表达于所有的组织和细胞。大多对单价和二价阳离子都有通透性。TRP通道与多种生物学功能有关,包括高血压、温度觉、血管炎症、刺激感、肿瘤增生、细胞内离子稳态及神经细胞信号转导。对这些通道的生理功能及其与人类疾病的关系的研究有助于开发具有潜在治疗价值的TRP通道调节剂。     

短柄禾叶蕨配子体发育的研究

首次通过人工培养的方式,详细记录了短柄禾叶蕨（Grammitis dorsipila (Christ.)C.Chr.）具代表性的配子体形态发育全过程及各环节的特征,包括孢子萌发、原丝体、毛状体、叶绿体、边缘细胞、精子器等,并附特征性结构照片29幅。为禾叶蕨科（Grammitidaceae）的研究积累了配子体发育方面的详实资料,并初步讨论了短柄禾叶蕨配子体特征所体现的系统学意义。     

Identification of quantitative trait loci for four morphologic traits under water stress in rice （Oryza sativa L.）

Late season drought coinciding with the rice booting to heading stage affects the development of plant height,panicle exsertion,and flag leaf size,and causes significant yield loss.In this study,a recombinant inbred line population derived from a cross between paddy and upland cultivars was used for data collection of the morphologic traits under well water and drought stress conditions.bought stress was applied at the stage of panicle initiation in the field in 2002 and at the booting stage in PVC pipes in 2003.The data from stress con ditions and their ratios(tait measured under stress condition/trait measured under well water condition)or differences(trait measured under stress condition minus trait measured under well water condition)were used for OTL analysis.Totally,17 and 36 QTLs for these traits were identified in 2002 and 2003,respectively,which explained a range of 2.58%-29.82%Of the phenotypic variation.Among them,six QTLs were commonly identified in the two years,suggesting that the drought stress in the two years was different.The genetic basis of these traits will provide useful information for improving rice late season drought resistance,and their application as indirect indices in rice late season drought resistance screening was also discussed.     

Estimation of fine root production, mortality and turnover with Minirhizotron in Larix gmelinii and Fraxinus mandshurica plantations

Fine root turnover is a major pathway for car-bon and nutrient cycling in forest ecosystems. However, to estimate fine root turnover, it is important to first understand the fine root dynamic processes associated with soil resource availability and climate factors. The objectives of this study were: (1) to examine patterns of fine root production and mortality in different seasons and soil depths in the Larix gmelinii and Fraxinus man-dshurica plantations, (2) to analyze the correlation of fine root production and mortality with environmental factors such as air temperature, precipitation, soil temperature and available nitrogen, and (3) to estimate fine root turn-over. We installed 36 Minirhizotron tubes in six mono-specific plots of each species in September 2003 in the Mao'ershan Experimental Forest Station. Minirhizotron sampling was conducted every two weeks from April 2004 to April 2005. We calculated the average fine root length, annual fine root length production and mortality using image data of Minirhizotrons, and estimated fine root turnover using three approaches. Results show that the average growth rate and mortality rate in L. melinii were markedly smaller than in F. mandshurica, and were high-est in the surface soil and lowest at the bottom among all the four soil layers. The annual fine root production and mortality in F. mandshurica were significantly higher than in L. gmelinii. The fine root production in spring and summer accounted for 41.7% and 39.7% of the total annual production in F. mandshurica and 24.0% and 51.2% in L. gmelinii. The majority of fine root mortality occurred in spring and summer for F. mandshurica and in summer and autumn for L. gmelinii. The turnover rate was 3.1 a-1 for L. gmelinii and 2.7 a-1 for F. mandshurica. Multiple regression analysis indicates that climate and soil resource factors together could explain 80% of the varia-tions of the fine root seasonal growth and 95% of the seasonal mortality. In conclusion, fine root production and mortality in L. gmelinii and F. mandshurica have dif-ferent patterns in different seasons and at different soil depths. Air temperature, precipitation, soil temperature and soil available nitrogen integratively control the dynamics of fine root production, mortality and turnover in both species.