外周血Treg细胞、T淋巴细胞及其亚群与早期宫颈癌的关系及对淋巴结转移的预测价值研究

摘要 目的：分析外周血Treg细胞、T淋巴细胞及其亚群与早期宫颈癌的关系及对淋巴结转移的预测价值。方法：选择我院自2017年1月至2020年12月接诊的60例接受子宫颈癌根治术及盆腔淋巴清扫术的早期宫颈癌患者作为观察组,另选同期的60例健康体检者作为对照组。比较两组外周血Treg细胞、T淋巴细胞及其亚群水平,使用受试者工作特征曲线（ROC）下面积（AUC）评价外周血Treg细胞、T淋巴细胞及其亚群对淋巴结转移的预测效能。结果：观察组外周血Treg细胞、CD8⁺T细胞水平高于对照组,CD3⁺T细胞、CD4⁺T细胞、CD4⁺/CD8⁺比值均低于对照组（P＜0.05）;观察组术后外周血Treg细胞、CD8⁺T细胞水平较术前降低,CD3⁺T细胞、CD4⁺T细胞、CD4⁺/CD8⁺比值均较术前升高（P＜0.05）;在60例早期宫颈癌患者中,发生淋巴结转移12例;淋巴结转移组术前外周血Treg细胞水平、CD8⁺T细胞高于非淋巴结转移组,CD3⁺T细胞、CD4⁺T细胞、CD4⁺/CD8⁺比值均低于非淋巴结转移组（P＜0.05）;经多因素Logistic回归分析,外周血Treg细胞、CD3⁺T细胞、CD4⁺/CD8⁺比值均是早期宫颈癌患者发生淋巴结转移的独立预测因素（P＜0.05）;经ROC曲线分析,外周血Treg细胞、CD3⁺T细胞联合CD4⁺/CD8⁺比值预测早期宫颈癌患者发生淋巴结转移的AUC为0.910。结论：外周血Treg细胞、T淋巴细胞及其亚群水平与早期宫颈癌的病情演变有关,其中外周血Treg细胞、CD3⁺T细胞联合CD4⁺/CD8⁺比值预测淋巴结转移的效能较好,值得进一步研究应用。     

外周血T细胞CD38和HLA-DR的表达水平在儿童传染性单核细胞增多症中的临床意义

摘要 目的：探讨传染性单核细胞增多症（IM）患儿外周血T细胞活化分子CD38和人类白细胞抗原DR（HLA-DR）表达水平的临床意义。方法：采用流式细胞术分别检测45例IM患儿急性期和恢复期的活化分子CD38和HLA-DR在T细胞的表达水平,并与30例健康体检儿童进行对比。分析IM患儿急性期CD38和HLA-DR在T细胞的表达水平与EB病毒载量、肝功能指标、外周血异型淋巴细胞比例、淋巴细胞计数的相关性,并采用ROC曲线分析CD8⁺CD38⁺T和CD8⁺HLA-DR+T细胞百分比的诊断效能。结果：与对照组比较,IM急性期患儿的CD38和HLA-DR在T细胞的表达水平显著升高（P＜0.05）。CD8⁺CD38⁺T、CD8⁺HLA-DR+T细胞百分比分别与EBV-DNA、ALT、AST、LDH、异型淋巴细胞百分比、淋巴细胞计数呈正相关（P＜0.05）,与白蛋白（ALB）呈负相关（P＜0.05）;CD4⁺CD38⁺T、CD4⁺HLA-DR+T细胞百分比与上述指标无显著相关性（P均＞0.05）。IM恢复期CD38和HLA-DR在T细胞的表达水平较急性期明显降低（P＜0.05）。ROC曲线分析CD8⁺CD38⁺T、CD8⁺HLA-DR+T细胞百分比显示诊断儿童IM的AUC值分别为0.931和0.993,特异度均为100%,灵敏度分别为88.89 %和93.33 %。结论：流式法检测CD38和HLA-DR在T细胞的变化有助于判断病情变化。外周血CD8⁺CD38⁺T、CD8⁺HLA-DR+T细胞百分比不仅能反映出IM急性期肝功能损伤严重程度,还可作为儿童IM的流式诊断指标。     

反复呼吸道感染儿童血清维生素A、维生素E水平与免疫球蛋白、T淋巴细胞亚群、NK细胞及骨密度的关系分析

摘要 目的：探讨反复呼吸道感染（RRTI）儿童血清维生素A、维生素E水平与免疫球蛋白（Ig）、T淋巴细胞亚群、NK细胞及骨密度的关系。方法：选择2018年2月至2020年12月我院儿科收治的107例RRTI患儿（感染组）和83例同期于我院体检的健康儿童（对照组）为研究对象,检测两组血清维生素A、维生素E水平、Ig水平,外周血T淋巴细胞亚群、NK细胞占比以及骨密度。分析维生素A、维生素E与Ig、T淋巴细胞亚群、NK细胞及骨密度的相关性。结果：感染组血清维生素A、维生素E、IgG、IgA、IgM及外周血CD3⁺T细胞百分比、CD4⁺T细胞百分比、CD3^-CD56⁺ NK细胞百分比、CD56brightNK细胞百分比、CD56dimNK细胞百分比、桡骨和胫骨骨密度均低于对照组（P＜0.05）,外周血CD8⁺T细胞百分比高于对照组（P＜0.05）。血清维生素A及维生素E水平与外周血CD8⁺T细胞百分比呈负相关（P＜0.05）,与IgG、IgA、IgM水平,外周血CD3⁺ T细胞百分比、CD4⁺T细胞百分比、CD3^-CD56⁺ NK细胞百分比、CD56brightNK细胞百分比、CD56dimNK细胞百分比、桡骨和胫骨骨密度呈正相关（P＜0.05）。结论：RRTI患儿血清维生素A、维生素E水平明显降低,且与免疫功能障碍和骨密度降低有关。     

卡瑞利珠单抗联合卡培他滨用于一线治疗复发转移鼻咽癌患者维持治疗疗效及对患者免疫功能的影响

摘要 目的：探讨卡瑞利珠单抗联合卡培他滨用于一线治疗复发转移鼻咽癌（NPC）患者维持治疗的疗效及对患者免疫功能的影响。方法：选取2020年1月至2022年1月钦州市第一人民医院收治的80例复发转移NPC患者,按照随机数字表法分为对照组和观察组,每组各40例。两组均接受吉西他滨联合顺铂化疗,对照组化疗后接受卡瑞利珠单抗单药维持治疗至1年,观察组化疗后接受卡瑞利珠单抗联合卡培他滨维持治疗至1年。比较两组疗效,不良反应,治疗前后B淋巴细胞亚群和自然杀伤（NK）细胞所占百分比的差异。结果：观察组客观缓解率（ORR）、疾病控制率（DCR）高于对照组（P＜0.05）。两组治疗后外周血CD5⁺B细胞、CD5⁺CD19⁺ B细胞、CD3^-CD56⁺NK细胞占比降低（P＜0.05）,但观察组治疗后外周血CD5⁺B细胞、CD5⁺CD19⁺ B细胞、CD3^-CD56⁺NK细胞占比高于对照组（P＜0.05）。两组Ⅲ度以上不良反应发生率比较差异无统计学意义（P＞0.05）。结论：卡瑞利珠单抗联合卡培他滨一线维持治疗复发转移NPC可提高临床疗效,减轻对细胞免疫功能的影响,且安全可靠。     

2型糖尿病并发肺结核患者PCT、HMGB1、CD4+/CD8+比值与继发肺部感染的关系

摘要 目的：探讨2型糖尿病并发肺结核患者降钙素原（PCT）、高迁移率族蛋白1（HMGB1）、CD4⁺/CD8⁺比值与继发肺部感染的关系。方法：选择2019年1月至2022年6月四川大学华西医院呼吸与危重症医学科收治的97例2型糖尿病并发肺结核患者,根据入院治疗时是否继发肺部感染分为肺部感染组（53例）及非肺部感染组（44例）。检测两组血清PCT、HMGB1水平以及外周血CD4⁺/CD8⁺比值。单因素和多因素Logistic回归分析2型糖尿病并发肺结核患者继发肺部感染的因素。受试者工作特征（ROC）曲线分析PCT、HMGB1和CD4⁺/CD8⁺比值预测2型糖尿病并发肺结核患者继发肺部感染的价值。结果：肺部感染组血清PCT、HMGB1水平高于非肺部感染组（P＜0.05）,外周血CD4⁺/CD8⁺比值低于非肺部感染组（P＜0.05）。糖化血红蛋白及血清PCT、HMGB1水平升高是2型糖尿病并发肺结核患者继发肺部感染的危险因素（P＜0.05）,高CD4⁺/CD8⁺比值是保护因素（P＜0.05）。PCT、HMGB1、CD4⁺/CD8⁺比值预测2型糖尿病并发肺结核患者继发肺部感染的曲线下面积为0.719、0.761、0.738,联合PCT、HMGB1和CD4⁺/CD8⁺比值预测的曲线下面积为0.878,高于各指标单独预测。结论：2型糖尿病并发肺结核患者血清PCT、HMGB1水平增高,外周血CD4⁺/CD8⁺比值降低,均与继发肺部感染有关,PCT、HMGB1联合CD4⁺/CD8⁺比值可辅助预测2型糖尿病并发肺结核患者继发肺部感染的风险。     

视频脑电图联合PEWS评分、NSE、CD4+/CD8+比值对病毒性脑炎患儿病情评估及预后预测的临床价值

摘要 目的：探讨视频脑电图（VEEG）联合儿童早期预警评分（PEWS）、神经元特异性烯醇化酶（NSE）、CD4⁺/CD8⁺比值对病毒性脑炎患儿病情评估及预后预测的价值。方法：选择2020年3月至2022年3月南京医科大学附属儿童医院收治的152例病毒性脑炎患儿，根据病情严重程度将患儿分为重症组（67例）和轻症组（85例），另选择72例无神经系统损伤住院患儿为对照组。治疗2周后，根据儿童格拉斯哥预后量表（CGOS）将其分为预后良好组（4~5级，89例）与预后不良组（1~3级，63例）。所有研究对象均接受PEWS测评和VEEG检查，检测血清NSE水平，计算CD4⁺/CD8⁺比值。采用单因素和多因素Logistic回归分析影响病毒性脑炎患儿预后的因素。采用受试者工作特征（ROC）曲线分析PEWS、VEEG 及血清NSE、CD4⁺/CD8⁺比值预测病毒性脑炎患儿预后的价值。结果：重症组PEWS、VEEG重度异常比例及血清NSE水平高于轻症组和对照组，CD4⁺/CD8⁺比值低于轻症组和对照组（P＜0.05）；轻症组PEWS、VEEG重度异常比例及血清NSE水平高于对照组，CD4⁺/CD8⁺比值低于对照组（P＜0.05）。预后不良组PEWS、VEEG重度异常比例、血清NSE水平高于预后良好组，CD4⁺/CD8⁺比值低于预后良好组（P＜0.05）。多因素Logistic回归分析结果显示，持续惊厥、高PEWS、VEEG重度异常、血清NSE水平升高是病毒性脑炎患儿预后不良的危险因素，CD4⁺/CD8⁺比值升高是保护因素（P＜0.05）。联合PEWS、VEEG 及血清NSE、CD4⁺/CD8⁺比值预测病毒性脑炎患儿预后曲线下面积为0.859，高于各指标单独预测。结论：病毒性脑炎患儿高PEWS、VEEG重度异常、血清NSE水平升高、CD4⁺/CD8⁺比值降低，与病情加重和预后不良有关，联合以上四项指标辅助预测病毒性脑炎患儿预后的价值较高。     

慢阻肺患者运动负荷气道反应性与T细胞亚群的关系

摘要 目的：探讨与分析慢性阻塞性肺疾病（COPD）患者运动负荷气道反应性与T细胞亚群的关系。方法：2020年1月到2022年4月选择在本院诊治的慢阻肺患者88例作为慢阻肺组,同期选择在本院进行健康体检者88例作为健康组,检测两组T细胞亚群含量,判定两组的运动负荷气道反应性情况并进行相关性分析。结果：慢阻肺组的CD8⁺T淋巴细胞比例明显高于健康组,CD3⁺T淋巴细胞、CD4⁺T淋巴细胞比例明显低于健康组（P<0.05）。慢阻肺组的运动负荷气道反应性发生率为20.9 %,明显高于健康组的1.2 %（P<0.05）。在慢阻肺中,Spearsman分析显示运动负荷气道反应性发生率与CD3+T淋巴细胞、CD4⁺T淋巴细胞、CD8⁺T淋巴细胞比例存在相关性（P<0.05）。logistic回归分析显示CD3⁺T淋巴细胞、CD4⁺T淋巴细胞、CD8⁺T淋巴细胞比例都为影响运动负荷气道反应性发生的重要危险因素（P<0.05）。结论：慢阻肺患者多伴随有T细胞亚群异常,也多伴随有运动负荷气道反应性,运动负荷气道反应性与T细胞亚群存在相关性,也表明T细胞亚群紊乱是导致运动负荷气道反应性发生的重要因素。     

脓毒症患者外周血T淋巴细胞PD-1表达变化及胸腺肽α-1的免疫调理作用研究

摘要 目的：探讨脓毒症患者外周血T淋巴细胞程序性细胞死亡受体1（PD-1）表达特点,分析胸腺肽?琢-1治疗对患者免疫功能的影响。方法：选择2018年3月至2020年6月我院重症医学科收治的140例脓毒症患者（脓毒症组）和同期于我院进行体检的95例健康志愿者（对照组）,根据急性生理与慢性健康评估Ⅱ（APACHE Ⅱ）、序贯器官衰竭评估（SOFA）评分结果将脓毒症患者分为APACHE Ⅱ 0~10分组（51例）、11~20分组（62例）和＞20分组（27例）;SOFA评分0~5分组（48例）、6~10分组（60例）和＞10分组（32例）。检测外周血CD4⁺T细胞上PD-1表达、CD8⁺T细胞上PD-1表达,比较组间差异性。Pearson秩相关性分析外周血CD4⁺T细胞上PD-1表达、CD8⁺T细胞上PD-1表达与APACHE Ⅱ、SOFA评分相关性。根据治疗方法将脓毒症患者分为A组（60例）和B组（80例）,A组给予常规综合治疗和乌司他丁治疗,B组在A组的基础上联合胸腺肽α-1治疗,比较两组治疗前后外周血T淋巴细胞（CD3⁺、CD4⁺、CD8⁺）、NK细胞（CD3-CD16⁺CD56⁺）差异。结果：脓毒症组外周血CD4⁺T细胞上PD-1表达、CD8⁺T细胞上PD-1表达高于对照组（P＜0.001）,外周血CD4⁺T细胞上PD-1表达、CD8⁺T细胞上PD-1表达随APACHE Ⅱ、SOFA评分的增加而增高,各组间差异显著（P＜0.05）。Pearson秩相关分析结果显示外周血CD4⁺T细胞上PD-1表达、CD8+T细胞上PD-1表达与APACHE Ⅱ评分、SOFA评分呈正相关（r=0.569、0.475;0.653、0.509,P均＜0.05）。B组治疗后CD3⁺、CD4⁺、CD3-CD16⁺CD56⁺高于A组（P＜0.05）,CD8⁺低于A组（P＜0.05）。结论：脓毒症患者外周血CD4⁺、CD8⁺T细胞上PD-1表达均增高,其表达与病情严重程度密切相关。给予胸腺肽α-1治疗可改善患者免疫功能。     

基于免疫性PTR的血小板膜糖蛋白及T/B淋巴细胞表达水平研究

摘要 目的：探究血小板膜糖蛋白及T/B淋巴细胞免疫在免疫性血小板输注无效发生机制中的重要作用。方法：采用血小板特异性抗体检测试剂盒及流式细胞技术检测免疫性PTR患者血小板特异性抗体（抗GPIIb/IIIa、抗GPIa/IIa、抗GPIb/IX、抗GPIV）、血小板膜糖蛋白（CD36、CD61、CD41a）表达情况及外周血T/B淋巴细胞数量,运用SPSS19.0软件及R软件分析免疫性PTR与血小板膜糖蛋白、外周血T/B淋巴细胞的相关性。结果：免疫性PTR与血小板输注有效者比较,血小板特异性抗体的产生无显著差异,血小板膜糖蛋白CD36和CD61的表达具有显著差异,CD36对免疫性PTR发生风险具有极大的预测价值,外周血CD8⁺T细胞比例增高,而CD4⁺T细胞比例减低。结论：免疫性PTR患者产生血小板抗体具体机制不明确,了解患者细胞免疫状态有助于明确免疫性PTR的发生机制,为患者提供更优质的诊疗策略。     

肺癌患者外周血T淋巴细胞分型与抗核抗体之间的关系研究

摘要 目的：研究肺癌患者外周血T淋巴细胞分型与抗核抗体之间的关系。方法：选择2019年1月到2021年6月在我院接受治疗的肺癌患者81例作为研究组,并选择同期健康志愿者81例作为对照组,检测并比较两组患者外周血CD4⁺、CD8⁺和CD4⁺/CD8⁺淋巴细胞比例,以及抗核抗体血清滴度。比较不同抗核抗体、年龄、性别、TNM分期、肿瘤分化程度以及病理类型肺癌患者外周血CD4⁺、CD8⁺和CD4⁺/CD8⁺淋巴细胞比例。结果：（1）肺癌患者外周血CD4⁺和CD4⁺/CD8⁺淋巴细胞比例显著低于对照组,而CD8⁺淋巴细胞比例显著高于对照组（P<0.05）;（2）III+IV肺癌患者外周血CD4⁺、和CD4⁺/CD8⁺淋巴细胞比例均显著低于I+II肺癌患者,而CD8⁺淋巴细胞比例均显著高于I+II肺癌患者（P<0.05）;（3）小细胞肺癌患者外周血CD4⁺、和CD4⁺/CD8⁺淋巴细胞比例均显著低于非小肺癌患者,而CD8⁺淋巴细胞比例均显著高于非小肺癌患者（P<0.05）;（4）肺癌患者抗核抗体血清滴度显著高于对照组（P<0.05）;（5）抗核抗体阳性患者CD4⁺和CD4⁺/CD8⁺淋巴细胞亚群比例均显著低于抗核抗体阴性患者,而CD8⁺淋巴细胞亚群比例显著高于抗核抗体阴性患者（P<0.05）。结论：肺癌患者外周血T淋巴细胞亚群表达异常,并且其表达水平可能与抗核抗体滴度有关。     

Serology and systematics of the Ebenales and the Theales

The systematic position ofthe Ebenaceae, Sapotaceae, Styracaceae, Ochnaceae, Stachyuraceae, Dipterocarpaceae, Clusiaceae and Hypericaceae has been investigated using serological comparisons of sets of antigenic determinants. The results show that the Sytracaceae and Sapotaceae are undoubtedly more closely associated with the Actinidiaeceae and Theaceae, respectively, than with each other. We found no corresponding determinants betnween antigen systems from the Ebenaceae and systems from any other family whose relations to this family have been proposed. As discovered previously, investigations of antigen systems from the Ochnaceae, Dipterocarpaceae, Stachyuraceae, Clusiaceae and Hypericaceae are against the idea of a natural order “Theales” in which these families, or at least some of them, are combined with the Theaceae and Actinidiaceae. This paper completes our previous investigations which largely support a superorder Ericanae sensu Ehrendorfer and Takhtajan. We propose to include the Actinidiaceae and Theaceae in this superorder, assigning them a central position laong with the Sapotaceae and Sytracaeae on one side and the Primulales and Ericales on the other. Another most interesting finding is that there are corresponding determinants between antigen systems from the members of the Ericanae and representatives of the Polemoniaceae and Loasaceae.     

The Choroid Plexuses and the Barriers Between the Blood and the Cerebrospinal Fluid

1. The fluid homeostasis of the brain depends both on the endothelial blood–brain barrier and on the epithelial blood–cerebrospinal fluid (CSF) barrier located at the choroid plexuses and the outer arachnoid membrane.2. The brain has two fluid environments: the brain interstitial fluid, which surrounds the neurons and glia, and the CSF, which fills the ventricles and external surfaces of the central nervous system.3. CSF acts as a fluid cushion for the brain and as a drainage route for the waste products of cerebral metabolism.4. Recent findings suggest that CSF may also act as a third circulation conveying substances secreted into the CSF rapidly to many brain regions.     

Epigenetics and aging: the targets and the marks

'Aging epigenetics' is an emerging field that promises exciting revelations in the near future. Here we focus on the functional and biological significance of the epigenetic alterations that accumulate during aging and are important in tumorigenesis. Paradigmatic examples are provided by the global loss of DNA methylation in aging and cancer and by the promoter hypermethylation of genes with a dual role in tumor suppression and progeria, such as the Werner syndrome (WRN) and lamin A/C genes. Another twist is provided by sirtuins, a family of NAD-dependent deacetylases that act on Lys16 of histone H4, which are emerging as a link between cellular transformation and lifespan.     

Biophysics and Structure of the Patch and the Gigaseal

Interpreting channel behavior in patches requires an understanding of patch structure and dynamics, especially in studies of mechanosensitive channels. High resolution optical studies show that patch formation occurs via blebbing that disrupts normal membrane structure and redistributes in situ components including ion channels. There is a 1-2 μm region of the seal below the patch where proteins are excluded and this may consist of extracted lipids that form the gigaseal. Patch domes often have complex geometries with inhomogeneous stresses due to the membrane-glass adhesion energy (E_a), cytoskeletal forces, and possible lipid subdomains. The resting tension in the patch dome ranges from 1-4 mN/m, a significant fraction of the lytic tension of a bilayer (∼10 mN/m). Thus, all patch experiments are conducted under substantial, and uneven, resting tension that may alter the kinetics of many channels. E_a seems dominated by van der Waals attraction overlaid with a normally repulsive Coulombic force. High ionic strength pipette saline increased E_a and, surprisingly, increased cytoskeletal rigidity in cell-attached patches. Low pH pipette saline also increased E_a and reduced the seal selectivity for cations, presumably by neutralizing the membrane surface charge. The seal is a negatively charged, cation selective, space with a resistance of ∼7 gigohm/μm in 100 mM KCl, and the high resistivity of the space may result from the presence of high viscosity glycoproteins. Patches creep up the pipette over time with voltage independent and voltage dependent components. Voltage-independent creep is expected from the capillary attraction of E_a and the flow of fresh lipids from the cell. Voltage-dependent creep seems to arise from electroosmosis in the seal. Neutralization of negative charges on the seal membrane with low pH decreased the creep rate and reversed the direction of creep at positive pipette potentials.     

The efficacy of ropivacaine and bupivacaine in the caesarean section and the effect on the vital signs and the hemodynamics of the lying-in women

ObjectiveTo investigate the efficacy of ropivacaine and bupivacaine in caesarean section and vital signs and the hemodynamics of the lying-in women.MethodsA total of 480 lying-in women who were admitted to this hospital for treatment between December 2017 and June 2018 were enrolled into this study as the subjects, which were divided into the experiment group and the control group, with 240 subjects in each group. In the experiment group, subjects received the local anesthesia by infusion of 1.5 mL ropivacaine (0.75%), while those in the control group also took the local anesthesia by infusion of 1.5 mL bupivacaine (0.75%). Thereafter, we observed the differences in the anesthetic efficiency, vital signs and hemodynamics of the lying-in women between two groups.ResultsThe excellent and good rates of the anesthesia in two groups were 92.1% and 87.9%, showing no obvious difference; in the experiment group, the average arterial pressures and systolic pressures at 5 min and 10 min after combined spinal and epidural analgesia (CSEA) were all elevated when comparing to the control group (all P < 0.05); in the experiment group, the onset time was obviously extended, while duration of sensory and motor block and the duration of motor block were all shorter than those in the control group (all P < 0.05). During anesthesia, the incidence rate of the adverse reactions in the control group was 2.50%, significantly higher than 0.83% in the experiment group (P < 0.05).ConclusionDespite that ropivacaine and bupivacaine are efficient in anesthesia in the CSEA in the caesarean section, ropivacaine is more recommended for little influence on the hemodynamics, shorter duration of sensory block and motor block and low incidence rate of adverse reactions, which are conducive to the recovery and also safe to the patients.     

On the structure and dynamics of the complex of the nucleosome and the linker histone

Several different models of the linker histone (LH)–nucleosome complex have been proposed, but none of them has unambiguously revealed the position and binding sites of the LH on the nucleosome. Using Brownian dynamics-based docking together with normal mode analysis of the nucleosome to account for the flexibility of two flanking 10 bp long linker DNAs (L-DNA), we identified binding modes of the H5-LH globular domain (GH5) to the nucleosome. For a wide range of nucleosomal conformations with the L-DNA ends less than 65 Å apart, one dominant binding mode was identified for GH5 and found to be consistent with fluorescence recovery after photobleaching (FRAP) experiments. GH5 binds asymmetrically with respect to the nucleosomal dyad axis, fitting between the nucleosomal DNA and one of the L-DNAs. For greater distances between L-DNA ends, docking of GH5 to the L-DNA that is more restrained and less open becomes favored. These results suggest a selection mechanism by which GH5 preferentially binds one of the L-DNAs and thereby affects DNA dynamics and accessibility and contributes to formation of a particular chromatin fiber structure. The two binding modes identified would, respectively, favor a tight zigzag chromatin structure or a loose solenoid chromatin fiber.     

Initiating and promoting the aquatic ecosystem health concept: the Society and the Journal

Since the 1970's the management of aquatic habitats has changed from piecemeal monitoring to the ecosystem approach; this was initiated in the North American Great Lakes, comprising social, economic, and environmental aspects. The information included in this paper is based on the presentation made at the Seminar On Ecosystem Approach To Water Management held in Oslo, Norway during 1991. Recently, the multidisciplinary, holistic, and integrated concept of ecosystem health has emerged, and is being advanced for the implementation of an ecosystem approach to environmental management, which has resulted in the formation of an international society (Aquatic Ecosystem Health & Management Society) and the publication of a primary journal (Journal of Aquatic Ecosystem Health). The information has been updated to incorporate new developments and recent progress about the Society and the journal since the Oslo Seminar.