Remedial habitat creation: does Nereis diversicolor play a confounding role in the colonisation and establishment of the pioneering saltmarsh plant, Spartina anglica?

Increasing concerns over global warming and expected sea level rises have led to the adoption of new coastal management strategies around the south-east coast of England. This paper explores the role played by the estuarine invertebrate Nereis diversicolor in limiting the colonisation and establishment of the invasive pioneering salt marsh plant, Spartina anglica. The biology of N. diversicolor is briefly reviewed and data from field experiments are presented demonstrating significant negative effects of worm abundance on transplanted S. anglica biomass. Laboratory-based experiments demonstrated significant negative effects of N. diversicolor abundance on the survival of S. anglica seeds transplanted to sediment cores. The importance of estuarine invertebrates in engineering the mudflat habitat may confound the foreseen ecosystem services and function provided by saltmarsh management schemes. Received: 15 February 1999 / Received in revised form: 4 June 1999 / Accepted: 11 June 1999     

江西与上海青少儿体质状况比较及影响因素分析

目的比较江西和上海儿童青少年生长发育差异及其影响因素。方法利用2000年全国学生体质调研数据,对江西和上海城乡6—22岁青少儿的身高、体重、BMI指数、肺活量体重指数等均值进行比较并作统计检验。结果上海学生体格发育水平明显好于江西学生,城、乡男生身高最大差距分别达7.6cm和10.7cm,城、乡女生身高最大差距分别为5.7cm和8.0cm;BMI指数显示上海学生身体充实度更好,但江西女生成年时体型相对粗壮;肺活量体重发育水平则上海学生显著低于江西学生。结论上海学生的青春期生长突增的开始时间早于江西学生,突增幅度大,增长时间也比后者长;而上海学生应加强户外活动以促进其肺功能。     

肺炎支原体肺炎患儿外周血白介素的表达与肺功能变化的相关性

目的:探讨肺炎支原体(MPP)肺炎患儿外周血中IL-10、IL-17的表达水平与肺功能变化的相关性。方法:选取70例肺炎支原体肺炎患儿为研究对象,以是否有哮鸣音分为喘息组和非喘息组,以30例健康儿童为对照组,空腹采血5ml,分离血清,ELISA检测血清中IL-10、IL-17的表达水平,肺功能检测仪检测受检者的第一秒用力呼气容积(PEV1),最大呼气流量(PEF),用力肺活量(FEV1/FVC)。结果:喘息组中IL-10的表达水平与对照组相比差异显著(P0.05),喘息组中IL-10的表达水平与非喘息组相比差异显著(P0.05),喘息组中IL-17的表达水平与对照组相比差异显著(P0.05),喘息组中IL-17的表达水平与非喘息组相比差异显著(P0.05)。喘息组和非喘息组中IL-10水平均低于对照组,喘息组和非喘息组中IL-17水平均高于于对照组。非喘息组较喘息组PEV1、PEF、PVE1/FVC值高,差异显著(P0.05)。肺炎支原体肺炎患儿血清中的IL-10的水平与PEV1、PEF、PVE1/FVC呈正相关,肺炎支原体肺炎患儿血清中的IL-17的水平与PEV1、PEF、PVE1/FVC呈负相关。结论:肺炎支原体肺炎患儿血清中IL-10、IL-17的表达水平与肺功能密切相关。     

髓内固定对老年股骨转子间骨折患者关节功能的影响

摘要 目的：研究髓内固定对老年股骨转子间骨折患者关节功能的影响。方法：选取2016年9月~2019年9月我院收治的股骨转子间骨折的老年患者80例为研究对象,采用随机数字表法将其分为两组,每组各40例。对照组患者采用Gamma钉进行治疗,观察组患者采用股骨近端防旋髓内钉固定治疗。比较两组患者的围术期相关指标、骨折愈合时间、Harris评分、临床治疗效果及并发症的发生情况。结果：观察组患者的手术时间、切口长度、术中出血量、术后引流量、住院时间及骨折愈合时间均显著少于或短于对照组(P＜0.05)。术前,两组患者的Harris评分比较无统计学差异(P＞0.05);术后6个月及术后12个月,两组患者的Harris评分均较术前显著升高,且观察组显著高于对照组(P＜0.05)。观察组患者的治疗优良率为92.50 %,显著高于对照组(75.00 %,P＜0.05)。两组患者深静脉血栓、感染、褥疮、固定松动、股骨头坏死及严重疼痛的发生率比较无统计学差异(P＞0.05)。结论：股骨近端防旋髓内钉固定治疗老年股骨转子间骨折效果明显优于Gamma钉治疗,可有效缩短骨折愈合时间,提高髋关节功能。     

Roles of Long-range Electrostatic Domain Interactions and K+ in Phosphoenzyme Transition of Ca2+-ATPase

Sarcoplasmic reticulum Ca²⁺-ATPase couples the motions and rearrangements of three cytoplasmic domains (A, P, and N) with Ca²⁺ transport. We explored the role of electrostatic force in the domain dynamics in a rate-limiting phosphoenzyme (EP) transition by a systematic approach combining electrostatic screening with salts, computer analysis of electric fields in crystal structures, and mutations. Low KCl concentration activated and increasing salt above 0.1 m inhibited the EP transition. A plot of the logarithm of the transition rate versus the square of the mean activity coefficient of the protein gave a linear relationship allowing division of the activation energy into an electrostatic component and a non-electrostatic component in which the screenable electrostatic forces are shielded by salt. Results show that the structural change in the transition is sterically restricted, but that strong electrostatic forces, when K⁺ is specifically bound at the P domain, come into play to accelerate the reaction. Electric field analysis revealed long-range electrostatic interactions between the N and P domains around their hinge. Mutations of the residues directly involved and other charged residues at the hinge disrupted in parallel the electric field and the structural transition. Favorable electrostatics evidently provides a low energy path for the critical N domain motion toward the P domain, overcoming steric restriction. The systematic approach employed here is, in general, a powerful tool for understanding the structural mechanisms of enzymes.     

微生物降解石油烃的功能基因研究进展

微生物对石油烃的降解在自然衰减去除土壤和地下水石油烃污染的过程中发挥了重要作用。微生物通过其产生的一系列酶来利用和降解这类有机污染物,其中,编码关键降解酶的基因称为功能基因。功能基因可作为生物标志物用于分析环境中石油烃降解基因的多样性。因此,研究石油降解功能基因是分析土著微生物群落多样性、评价自然衰减潜力与构建基因工程菌的重要基础。本文主要介绍了烷烃和芳香烃在有氧和无氧条件下的微生物降解途径,重点总结了烷烃和芳香烃降解的主要功能基因及其作用,包括参与羟化作用的单加氧酶和双加氧酶基因、延胡索酸加成反应的琥珀酸合酶基因以及中心中间产物的降解酶基因等。     

Gene microarray analysis of expression profiles in Suberoyllanilide hyroxamic acid-treated Dendritic cells

Objective

The purpose of this study is to provide a further theoretical basis for the role of Suberoyllanilide hyroxamic acid (SAHA) affect on Dendritic cells (DCs).

Specific Activation of Insulin-like Growth Factor-1 Receptor by Ginsenoside Rg5 Promotes Angiogenesis and Vasorelaxation

Ginsenoside Rg5 is a compound newly synthesized during the steaming process of ginseng; however, its biological activity has not been elucidated with regard to endothelial function. We found that Rg5 stimulated in vitro angiogenesis of human endothelial cells, consistent with increased neovascularization and blood perfusion in a mouse hind limb ischemia model. Rg5 also evoked vasorelaxation in aortic rings isolated from wild type and high cholesterol-fed ApoE^−/− mice but not from endothelial nitric-oxide synthase (eNOS) knock-out mice. Angiogenic activity of Rg5 was highly associated with a specific increase in insulin-like growth factor-1 receptor (IGF-1R) phosphorylation and subsequent activation of multiple angiogenic signals, including ERK, FAK, Akt/eNOS/NO, and G_i-mediated phospholipase C/Ca²⁺/eNOS dimerization pathways. The vasodilative activity of Rg5 was mediated by the eNOS/NO/cGMP axis. IGF-1R knockdown suppressed Rg5-induced angiogenesis and vasorelaxation by inhibiting key angiogenic signaling and NO/cGMP pathways. In silico docking analysis showed that Rg5 bound with high affinity to IGF-1R at the same binding site of IGF. Rg5 blocked binding of IGF-1 to its receptor with an IC₅₀ of ∼90 nmol/liter. However, Rg5 did not induce vascular inflammation and permeability. These data suggest that Rg5 plays a novel role as an IGF-1R agonist, promoting therapeutic angiogenesis and improving hypertension without adverse effects in the vasculature.     

细胞色素P450酶的结构、功能与应用研究进展

细胞色素P450 (cytochrome P450,CYP)酶是广泛存在于微生物、动植物及人体中与膜结合的血红蛋白类酶,具有氧化、环氧化、羟化、去甲基化等多种生物催化活性。CYP酶在药物、类固醇、脂溶性维生素和许多其他类型化学物质的代谢中具有重要作用,其在异源物质的解毒、药物相互作用和内分泌功能等领域的研究是热点问题。本综述对CYP的结构、功能、临床应用与开发前景进行了概述,并对其最新的研究现状和发展前景进行探讨。     

结扎大鼠左冠状动脉不同时间制备心肌梗死模型的比较

目的探索大鼠左冠状动脉前降支不同结扎处理后,对心肌形态学及心功能的影响,以建立适合移植干细胞再生修复心肌梗死研究的稳定、可靠和更合乎发病机制的动物模型。方法雄性SD大鼠70只,随机分为五组。即:结扎(15、30、456、0 min)再灌、结扎非再灌。于处理后1 d、1周2、周或4周动态观察心肌梗死变化,并于处理一月后测量动脉收缩压(ASP)、动脉舒张压(ADP),左室收缩压(LVSP),左室舒张末压(LVEDP)及左室压力上升及下降最大速度(±dp/dtmax)。结果引起明显的心肌梗死至少需要结扎30 min。结扎(456、0 min)再灌、结扎非再灌的心肌梗死明显,并观察到梗死区域心肌已绝大部分纤维化,且梗死面积变化较恒定。同时测定不同结扎时间心功能的变化发现,结扎(456、0 min)再灌或结扎非再灌各组ASP、DAP、LVSP、±dp/dtmax显著下降,LVEDP明显升高。并见不同结扎时间处理后,大鼠心功能的变化与心肌梗死后的梗死面积变化密切相关。结论建立了实验大鼠左冠状动脉前降支中上1/3处结扎45 min以上的大鼠心肌梗死模型。不仅合乎临床心肌梗死的发病机制,而且梗死部位、梗死区域面积稳定,适合于移植细胞再生修复心肌梗死的研究。