阿苯达唑体外对微小膜壳绦虫损伤作用的组织学变化

目的：应用形态学方法观察比较阿苯达唑在２４ｈ、７２ｈ对微小膜壳绦虫损伤的组织学改变。方法：用ＨＥ染色方法，对阿苯达唑作用后的微小膜壳绦虫的组织变化进行光镜下观察。结果：２４ｈ虫体节片拉长，皮层水肿增粗，表面绒毛脱落，基膜增厚，实质区水肿明显。７２ｈ皮层区基底膜及皮下肌细胞脱落，虫体表面呈糜烂状；实质区呈空网格状改变，排泄管扩张，出现核固缩、核碎裂现象。结论：阿苯达唑对微小膜壳绦虫具有较强损伤作用。     

Triggering immunological memory against the tapeworm Hymenolepis diminuta to protect against colitis

Infection with parasitic helminths can ameliorate the severity of concomitant inflammatory disease. To use the tapeworm, Hymenolepis diminuta, and to extend this concept by assessing whether triggering a memory response against the worm inhibits dinitrobenzene sulphonic acid (DNBS)‐induced colitis in Balb/c mice. Initial studies revealed that oral infection with 1, 3 or 5 H. diminuta cysticercoids 8 days before intrarectal administration of DNBS (3 mg) resulted in less severe inflammation and that infected mice displayed an increased propensity for T helper‐2 immunity. A 1 mg dose of a PBS‐soluble extract of the worm (HdAg) delivered intraperitoneally concomitant with DNBS was anticolitic as determined by macroscopic and histological disease scores 72 hour post‐DNBS. Mice infected 28 days previously had a memory response as determined by HdAg‐evoked increases in interleukin (IL)‐4 and IL‐10 from in vitro stimulated splenocytes and serum anti‐H. diminuta IgG. Moreover, mice infected with 5 H. diminuta 28 days previously were protected from DNBS‐induced colitis by secondary infection or 100 μg HdAg (ip.) at the time of DNBS treatment. An additional approach to managing inflammatory disease could be infection with H. diminuta followed by eliciting antiworm recall responses.     

Bromophenols from the brown alga Leathesia nana

Two new bromophenols, (E)-3-(2,3-dibromo-4,5-dihydroxyphenyl)-2-methylpropenal (1) and 3-(2,3-dibromo-4,5-dihydroxyphenyl)-2-methyl-1-propanol (2), together with 11 known bromophenols (3-13), were isolated from the ethanolic extract of the brown alga Leathesia nana S. et G. Their structures have been elucidated by spectroscopic methods, including IR, MS, HRMS, 1D and 2D NMR techniques.     

缩小膜壳绦虫感染1例报告

本文报道了在血吸虫病调查中发现1例缩小膜壳绦虫感染儿童,用吡喹酮治愈。     

云南大理下关野栖小兽微小膜壳绦虫感染调查

为初步了解大理市下关野栖小兽类哺乳动物微小膜壳绦虫感染的情况，采用捕鼠笼和鼠夹捕捉小兽类哺乳动物，共捕获小兽526只，分属3目5科10属20种，以齐氏姬鼠为优势种，占29．86％；感染小兽77只，分属2目8种，感染率14．64％，其中以卡氏小鼠、中华姬鼠、白腹鼠和齐氏 姬鼠的感染率较高，分别为40．48％，29．03％，18．75％和18．47％。大理市下关野栖小兽微小膜壳绦虫感染率较高，有必要进行预防和控制人群微小膜壳绦虫病。     

湛江市区褐家鼠和黄胸鼠膜壳绦虫感染调查

目的　了解广东省湛江市区褐家鼠和黄胸鼠膜壳绦虫的感染情况。　方法　笼诱捕获褐家鼠和黄胸鼠 ,乙醚处死后解剖检查膜壳绦虫感染情况。　结果　在捕获的 2 0 3只鼠中检出 5 2只感染膜壳绦虫 ,感染率 2 5 .62 % ;其中 2只同时感染缩小膜壳绦虫和微小膜壳绦虫。褐家鼠膜壳绦虫感染率明显高于黄胸鼠 (分别为 2 9.80 %和 13 .46% ,P <0 .0 5 )。鼠膜壳绦虫感染率与其体重显著相关。缩小膜壳绦虫感染度为 1～ 65条 ,平均为 (5 .3 88± 10 .2 3 2 )条 ;微小膜壳绦虫感染度为 1～ 10条 ,平均 (5 .2 0 0± 3 .70 1)条。缩小膜壳绦虫寄生于鼠胃、小肠和大肠 ;微小膜壳绦虫寄生于鼠小肠。结论　湛江市区褐家鼠和黄胸鼠膜壳绦虫的感染较为普遍 ,对人类健康构成一定威胁     

Herbivory and warming interact in opposing patterns of covariation between arctic shrub species at large and local scales

A major challenge in predicting species’ distributional responses to climate change involves resolving interactions between abiotic and biotic factors in structuring ecological communities. This challenge reflects the classical conceptualization of species’ regional distributions as simultaneously constrained by climatic conditions, while by necessity emerging from local biotic interactions. A ubiquitous pattern in nature illustrates this dichotomy: potentially competing species covary positively at large scales but negatively at local scales. Recent theory poses a resolution to this conundrum by predicting roles of both abiotic and biotic factors in covariation of species at both scales, but empirical tests have lagged such developments. We conducted a 15-y warming and herbivore-exclusion experiment to investigate drivers of opposing patterns of covariation between two codominant arctic shrub species at large and local scales. Climatic conditions and biotic exploitation mediated both positive covariation between these species at the landscape scale and negative covariation between them locally. Furthermore, covariation between the two species conferred resilience in ecosystem carbon uptake. This study thus lends empirical support to developing theoretical solutions to a long-standing ecological puzzle, while highlighting its relevance to understanding community compositional responses to climate change.

A readily observable phenomenon in nature is the tendency for the distributions of potentially competing species to covary positively at large spatial scales but negatively at small scales (1, 2). This scale dependence in patterns of species covariation is a defining phenomenon in ecology (3), and a classic illustration of it derives from MacArthur’s observations of Dendroica sp. warblers in mixed forests of the northeastern United States (1) and related theoretical work (4, 5). However, while opposing patterns of species covariation at large and local scales are ubiquitous, assigning causality to interacting drivers of such patterns in natural systems is challenging. Originally, theory explained this phenomenon as a product of distinct types of drivers of species abundance and distribution at large versus local scales. According to this framework, regional factors, such as climate, determine species’ distributions over large scales, while biotic interactions such as exploitation and interference determine presence, absence, and relative abundances of species at local scales (5–10). Hence, species with similar resource demands should, and often do, overlap spatially (covary positively) at broad scales as their distributions track abiotic niche requirements such as favorable climatic conditions (11). Meanwhile, the same species should, and often do, covary negatively at smaller spatial scales, where local biotic interactions such as competition, interference, niche complementarity, or exploitation by consumers or pathogens promote exclusion or segregation (5, 12–14). More recent theoretical developments have, however, highlighted the potential for roles of both types of drivers in patterns at both scales (7, 15, 16). Understanding whether, and how, climate and biotic interactions simultaneously influence species’ covariation at large and local scales has been repeatedly identified as a key challenge in improving predictions of species’ distributional and biodiversity responses to climate change (15, 17, 18).In contrast to progress in theory, field experimental tests of such potential interactions between biotic and abiotic factors in opposing patterns of species covariation at large and local scales have been lacking (14), in part because of the challenges inherent in conducting sufficiently controlled field experiments over suitably long time scales (19, 20). Consequently, novel empirical support for the role of, for example, biotic interactions in large scale patterns of species covariation has been strictly observational (21). Application of more robust empirical tests of predictions deriving from recent theory on this topic may also improve understanding of the consequences of patterns of species covariation at opposing spatial scales for important aspects of ecosystem function (22), including carbon exchange (23–26). Here, we present results of a 15-y warming and herbivore-exclusion experiment conducted at a remote arctic field site aimed at investigating influences of both drivers on patterns of covariation between two dominant shrub species at local and large spatial scales. The experimental design targets temperature as the abiotic limiting factor and herbivory (and associated ancillary effects) as the biotic limiting factor (Methods).The two focal shrub species in this study, dwarf birch (Betula nana) and gray willow (Salix glauca), hereafter “birch” and “willow,” respectively, are the most abundant plant species at our study site in low-arctic Greenland (27), and their functional role in ecosystem CO₂ exchange far exceeds that of any other vascular plant species at the site (28, 29). Furthermore, the two species are codominant across much of the Arctic (Fig. 1) (30, 31), but some experimental evidence indicates that Betula has the capacity to outcompete Salix at local scales in the Arctic due to its greater developmental plasticity and ability to invest rapidly in stem growth (32). Hence, although annual sampling throughout the duration of our experiment has assessed aboveground dynamics of all components of the plant community (Methods), our focus here is on patterns of covariation between birch and willow. Although birch is generally more common than willow across the study site (SI Appendix), the two species share similar distributions across the site, occur mainly on low to mid elevation slopes and plateaus, and predictably avoid arid steep slopes and stagnant mesic or saturated lowlands and fens (Fig. 1B). Each of the two species readily forms monospecific “shrub islands” at the local scale (Fig. 1C and SI Appendix, Fig. S3).Open in a separate windowFig. 1.(A) Circum-Arctic distributions of the two focal shrub species, dwarf birch (B. nana) and gray willow (S. glauca). Shaded polygons were derived from published range maps (30, 65). Point locations were derived from occurrence records (66–68) and the GBIF data portal (www.gbif.org). (B and C) Landscape and local scale views of patterns of covariation between the two species at the study site near Kangerlussuaq, Greenland. (B) South-facing hillside and lowland plains at the study site illustrating cooccurrence of dwarf birch (B. nana) and gray willow (S. glauca) at the landscape scale. (C) Monospecific shrub islands of each species are evident at smaller plot scales at the study site. In both photographs, birch appears dark or olive green, while willow appears lighter green. Image credit: E.P.     

库鲁木提草对自发性高血压大鼠的降压作用及机制研究＊

目的 探究库鲁木提草水提液对自发性高血压大鼠的降压作用及机制。方法 将58只自发性高血压大鼠根据体重、血压随机分为5组：高血压对照组（n=12）、库鲁木提草水提液低剂量组（n=12）、库鲁木提草水提液中剂量组（n=12）、库鲁木提草水提液高剂量组（n=12）、厄贝沙坦阳性对照组（n=10），正常血压大鼠10只作为正常血压对照。大鼠灌胃治疗8周，研究库鲁木提草水提液对自发性高血压大鼠的降压及心血管保护作用的有效性及机制。结果 与空白组比较，库鲁木提草水提液治疗后可降低自发性高血压大鼠的收缩压、舒张压及平均动脉血压，库鲁木提草水提液降压作用差于厄贝沙坦。库鲁木提草水提液能改善自发性高血压大鼠心脏功能并减轻了心肌纤维化。库鲁木提草水提液还改善了自发性高血压大鼠的循环一氧化氮水平，并降低血清内皮素-I和血管紧张素-Ⅱ水平。结论 库鲁木提草水提液能够降低自发性高血压大鼠血压，改善内皮细胞功能紊乱和心脏重塑。