大蒜素对致死型约氏疟原虫鼠疟模型CD4+活化/凋亡T细胞的影响

探讨大蒜素对致死型约氏疟原虫(Plasmodium yoelii 17XL,P.y 17XL)感染BALB/c小鼠T细胞免疫应答的影响。P.y 17XL感染后第0~2天每日口服给予不同浓度大蒜素(3 mg/kg或9 mg/kg)处理;动态监测各组小鼠原虫血症水平和生存期;感染后第0天、第3天和第5天无菌提取小鼠脾细胞,FACS检测小鼠活化T细胞(CD4~+CD69~+)、凋亡CD4~+T细胞(7AAD~-Annexin V~+)数量变化;ELISA检测脾细胞培养上清中IFN-γ和TNF-α的水平。结果显示:与NC组相比,大蒜素处理组能降低感染小鼠的原虫血症水平,延长生存期。大蒜素处理能提高感染小鼠活化T细胞的数量,降低凋亡T细胞数量,并能提高脾细胞培养上清中IFN-γ和TNF-α的水平。大蒜素能在感染早期促使宿主建立有效的Th1免疫应答,从而抑制红内期P.y 17XL疟原虫感染进程。     

BALB/c小鼠感染不同疟原虫CD4＋ Th应答和凋亡特点的比较研究

探讨不同疟原虫感染BALB/c小鼠的免疫应答特点。BALB/c小鼠经腹腔注射致死型约氏疟原虫（P.y17XL）和夏氏疟原虫（P.cAS）感染的红细胞,计数红细胞感染率;ELISA动态检测感染小鼠脾细胞培养上清中IFN-γ和IL-4水平;流式细胞术检测脾中CD4＋T细胞凋亡数量。约氏疟原虫（P.y17XL）感染早期,小鼠原虫血症持续上升;IFN-γ和IL-4分泌水平仅在感染后第3天出现一过性有意义的升高,而且峰值较低;脾中CD4＋T细胞大量凋亡,小鼠全部死亡;而夏氏疟原虫（P.cAS）感染小鼠,原虫血症上升缓慢;IFN-γ分泌水平在感染后第5天达峰值;IL-4分泌水平在感染后第10天达峰值,且峰值较高维持时间较长;脾中CD4＋T细胞凋亡细胞于感染后8 d出现有意义升高,小鼠全部存活。抗疟保护性免疫有赖于Th1和Th2型免疫应答的有效建立和协调过渡,感染期间CD4＋T细胞凋亡的时相和数量可能是影响免疫应答的强度或引起宿主免疫抑制的原因,从而影响宿主疟原虫感染的结局。     

TLR7激动剂对P.y 17XNL感染BALB/c小鼠免疫调节效应的影响

宿主抗疟保护性免疫应答的水平和强度与疟疾预后关系密切,当疟原虫侵袭宿主时,TLRs向机体传达病原体入侵信息,激活免疫系统。采用TLR7激动剂处理P.y 17XNL感染的BALB/c小鼠,通过FACS和ELISA检测DC亚群(mDC和pDC)、CD4~+ T细胞亚群(Th1、Th2、Tfh和Treg)和细胞因子(IFN-γ、IL-4、IL-21和IL-10)的水平,明确TLR7通过DC调控宿主应答的免疫机制。结果显示,TLR7激动剂能够促进DC亚群数量的增加,同时也提高Th1和Tfh细胞分化,并显著增加IFN-γ分泌水平。因此,TLR7激动剂通过诱导DC活化,促进Th1型免疫应答降低原虫血症水平,在疟疾感染过程中发挥保护性免疫作用。     

重组IL-33在致死型约氏疟原虫感染中对细胞因子表达的影响及意义

探讨IL-33作为外源性细胞因子对致死型约氏疟原虫感染的细胞因子表达的影响及意义。以致死型约氏疟原虫(Plasmodium yoelii 17XL,P.y 17XL)感染BALB/c小鼠为研究对象,感染D0-D5腹腔注射重组IL-33,动态观察原虫血症。感染后3 d和5 d,无菌制备脾细胞悬液,P.y 17XL原虫裂解物体外刺激脾细胞培养72 h。采用多因子检测方法对脾细胞培养上清多种细胞因子进行定量分析。与对照组相比,IL-33给药组原虫血症上升缓慢,原虫血症峰值延迟出现。与对照组相比,IL-33给药组脾细胞培养上清IFN-γ、IL-6、TNF-α和IL-18表达明显下调,而IL-5表达水平明显增加。趋化因子MIP-1β、MIP-1α、RANTES和GRO-α表达明显降低。重组IL-33在P.y 17XL感染过程中通过下调趋化因子表达,减少炎症细胞浸润进而降低前炎症细胞因子表达。通过上调IL-5表达,增强嗜酸性粒细胞活性进而发挥控制P.y 17XL原虫增殖的作用。     

血吸虫感染通过抑制前炎症免疫应答缓解实验性脑疟的发生

脑疟所引起的严重神经系统的并发症是引起5岁以下儿童死亡的主要原因。疟疾宿主体内免疫应答紊乱是引起脑疟发生的重要机制。目前在疟疾流行区,疟疾患者常常伴有蠕虫感染,但感染虫株类型,严重程度以及感染途径不同均会影响感染结局。为探讨前炎症免疫应答在混合感染中的作用地位,采用日本血吸虫和ECM模型来探讨相关免疫机制。通过建立混合感染模型,监测原虫血症水平和宿主生存期;FACS检测脾脏中DC亚群、巨噬细胞、Treg以及相关功能分子CD86、TLR4、TLR9的表达水平;ELISA和Griess法检测脾细胞培养上清中IL-10、TNF-α、IFN-γ和NO的分泌水平。日本血吸虫感染增加ECM小鼠体重,降低原虫血症,延长小鼠生存期。混合感染抑制ECM模型小鼠脾脏DC亚群和巨噬细胞的数量,TLR9的表达水平也显著降低。ELISA和Griess检测结果显示混合感染显著降低ECM前炎症细胞因子TNF-α、IFN-γ和NO的表达水平,同时增加Treg的数量和IL-10的表达水平。结果表明,日本血吸虫感染会通过抑制前炎症免疫应答来缓解ECM的发生,从而延长宿主生存期。     

香菇多糖对急性弓形虫感染小鼠Th应答调节作用的实验研究

目的 探讨香菇多糖(Lentinan,Lent)对急性弓形虫感染小鼠BALB/c Th1/Th2免疫应答调节效应的影响.方法 对RH强毒株感染的BALB/c小鼠进行不同时间点的香菇多糖预处理,动态观察用药后各组感染小鼠的生存率;在感染后第0、3、5、8和10天提取小鼠的脾细胞,ELISA法检测脾细胞培养上清中IFN-γ和IL-10的分泌水平.结果 感染前6 d 1 mg/kg LNT用药组与药物未处理组相比显著提高了生存率;显著增强了Th1免疫应答中关键细胞因子IFN-γ和Th2免疫应答中关键细胞因子IL-10的分泌水平.结论 对急性弓形虫感染的BALB/c小鼠采用香菇多糖预处理之后能有效激发Th1/Th2型免疫应答的有效建立,对于抵抗弓形虫感染具有重要意义.     

IL-10在Plasmodium yoelii 17XL和Plasmodium chabaudi AS疟原虫混合感染宿主病理损伤中的作用研究

为探讨IL-10在致死型约氏疟原虫(Plasmodium yoelii 17XL,P.y17XL)和夏氏疟原虫(Plasmodiumchabaudi AS,P.cAS)混合感染宿主病理损伤中的作用,用P.y17XL、P.cAS和P.y17XL+P.cAS分别感染DBA/2小鼠,计数红细胞感染率;感染后第3、5、8、10、12和19天分别尾静脉取血,肝素抗凝后短暂离心,采用高纯度DNA提取试剂盒抽提DNA,实时定量PCR检测虫负荷水平;感染后第0、1、3、5、8、10、12和15天制备脾细胞悬液,ELISA检测脾细胞培养上清中IL-10水平。实验结果发现,P.y17XL单独感染和混合感染小鼠IL-10水平在感染后第5天和第8天分别达峰值,随后开始下降至正常水平,小鼠虫血症均达中等水平,存活率100%;相比P.cAS感染小鼠IL-10在感染后第3天突然出现高水平升高并且维持时间较长;于感染后第8天达峰值,是同天P.y17XL单独感染和混合感染小鼠IL-10水平的2倍,虫血症水平较高,小鼠全部死亡。同时实时定量PCR结果发现,混合感染小鼠,于感染后3～12 d P.y17XL增殖占优势,而感染后15～19 d则P.cAS增殖处于优势状态。表明以IL-10为核心的免疫调节网络与疟疾感染过程中病理损伤密切相关。同时提示混合感染小鼠应答模式与P.y17XL感染小鼠的应答模式相同。     

预防性给予维生素D对实验性脑疟前炎症应答的影响

通过预防性给予维生素D(Vitamin D,VD)治疗,研究VD对实验性脑疟(ECM)模型鼠感染结局及免疫应答的影响,进一步阐明VD的免疫调节作用。通过P.b ANKA感染的C57BL/6小鼠建立ECM模型,通过ELISA和Griess法检测了预防给予VD对实验组小鼠脾上清和血清中前炎性细胞因子(IFN-γ、TNF-α和NO)和抗炎性细胞因子(IL-10)水平的影响,并检测了血脑屏障通透性的变化。结果显示,VD处理能够显著延长宿主生存期,同时显著降低血清和脾上清中的前炎性细胞因子水平,显著提升抗炎性细胞因子水平,从而保护血脑屏障完整性,进而抑制脑疟发生。结果表明,预防性给予VD治疗可以通过抑制宿主前炎症免疫应答以防止脑疟发生。     

TLR7刺激对系统性红斑狼疮易感型小鼠树突状细胞免疫功能的影响

目的研究TLR7通路对于系统性红斑狼疮易感Fas-/-MRLlpr/lpr小鼠树突状细胞免疫功能的影响。方法 从5周龄MRLlpr/lpr小鼠骨髓提取DC体外培养,以TLR7激活剂咪喹莫特处理48h,流式细胞仪检测细胞表面分子CD80、MHCⅡ表达。ELISA法检测细胞培养上清中细胞因子IFN-γ、TNF-α、IL-10。结果咪喹莫特处理后,树突状细胞表面抗原提呈相关分子MHCⅡ和CD80分子均降低,分泌的IFN-γ、TNF-α和IL-10均明显增加。结论 TLR7通路调节系统性红斑狼疮易感小鼠MRLlpr/lpr小鼠DC抗原呈递能力,具有影响免疫应答作用。     

蛋氨酸脑啡肽对疟疾感染鼠一氧化氮产生的研究

探讨蛋氨酸-脑啡肽(M-ENK)对约氏疟原虫感染早期小鼠脾细胞分泌一氧化氮(NO)的免疫调节效应及相关机制。以不同浓度的M-ENK(单独或与LPS合用)与疟原虫感染后第3dBALB/c或DBA/2小鼠的脾细胞共同培养,通过Griess反应和ELISA法分别检测其上清中NO和IFN-γ的水平。脾细胞与浓度为10-10或10-11mol/L的M-ENK培养后,NO的分泌水平明显升高,并且与LPS联合刺激后其NO的产生进一步增强,但IFN-γ水平均未出现有意义的变化。提示浓度为10-10或10-11mol/L的M-ENK能够促进约氏疟原虫感染小鼠脾细胞NO的产生,该作用与IFN-γ活化巨噬细胞路径可能无关,同时M-ENK对LPS的刺激效应也具有强化作用。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.