松萎蔫病病原的研究

为了探讨松萎蔫病与松材线虫的关系,笔者研制了一种简单试验装置"冷闸",使接种的线虫被隔离在松树接种枝内而不能迁移.用该装置进行接种试验的结果表明:在松材线虫被局限于接种枝内而不能移动到寄主其他部位的情况下,接种无菌松材线虫与致病荧光假单胞菌Pseudomonas fluorescerns(GcM5-1A),以及该致病细菌体外培养的无细胞滤液,同样能诱发该病.该致病细菌又从接种无菌线虫和致病细菌后病死寄主中分离到并被鉴定,证明符合柯赫法则.致病荧光假单胞菌GcM5-1A体外培养的无细胞滤液接种试验结果说明,该致病菌株培养物中的内吸性毒素导致了寄主的萎蔫和死亡.由此,松萎蔫病经实验证实为首例由细菌和线虫互惠共生复合体引起的植物病害.     

马尾松毛虫幼虫的超微结构

<正>马尾松毛虫(Dendrolimus punctatus walker)是我国林业上的重大害虫,在我国南方地区严重危害马尾松。我们于1983和1984年对马尾松幼虫体壁及消化道等作了超微结构的研究,本文就SEM及TEM观察的部份结果予以报导。 材料和方法 本研究以马尾松毛虫4龄幼虫为材料,用光学显微镜观察组织切片和用电子扫描显微镜观察体表超微结构,透射电子显微镜观察超薄切片。 组织切片制法是用Bouin氏液固定材料,石蜡切片,苏木精及伊红染色方法制作玻片标本。 电子显微镜超微结构样品的制备方法如下: 用乙醚麻醉后的马尾松毛虫4龄幼虫,置入2％戊二醛液内,在双筒体视显微镜下解剖:     

云南程海蓝藻毒性研究

将云南省程海采集的微囊藻和鱼腥藻干粉分别添加到小鼠饲料中饲喂小白鼠，随添加剂量的增加，动物出现不同程度的中毒现象．用生理盐水浸泡的微囊藻、鱼腥藻粗提液给小白鼠腹腔注射的急性动物实验及血凝反应表明，微囊藻和鱼腥藻粗提液能使动物产生中毒反应，甚至死亡，同时也能产生血凝反应     

粘虫血淋巴溶菌酶的纯化及其对染病小白鼠的初试

给粘虫注射大肠杆菌，血淋巴中溶菌酶活性增强，然后用琼脂糖（ＣＭＳｅｐｈａｒｏｓｅ）离子交换层析法纯化溶菌酶。小白鼠先注射致病的阴沟肠杆菌，一小时后腹腔注射从粘虫免疫血淋巴纯化的溶菌酶，结果处理小白鼠死亡率比对照组低，说明试虫血淋巴中的溶菌酶在小白鼠体内可能有一定的抗菌作用。     

黑足凹眼姬蜂生物学特性的研究

<正>黑足凹眼姬蜂是马尾松毛虫幼虫重要的寄生性天敌,在江苏、安徽两省,对马尾松毛虫幼虫的平均寄生率为3.4～50％。该蜂在南京一年发生5代,以幼虫在3～4龄越冬代马尾松毛虫幼虫体内越冬。卵～幼虫期28d,蛹期10～20d,成虫在白天交尾、产卵。成虫寿命2.8～13.6d。无趋光性。雌蜂的平均怀卵量67～207。黑足凹眼姬蜂的茧蛹重寄生天敌有8种,平均重寄生率27.9％,最高重寄生率29.5％(越冬代),其中以次生大腿小蜂为主。     

微量法测定产气荚膜梭菌α毒素

为了快速、灵敏地测定样品中的产气荚膜梭菌α毒素，本实验以产气荚膜梭菌培养滤液经硫酸铵分段盐析、丙酮分段沉淀及凝胶过滤得精制α毒素，在96孔细胞板上，经卵黄反应浊度(微量)法测定精制α毒素及培养滤液卵黄反应滴度分别为1：32768和1：2048，且该方法特异性强、稳定性好，是产气荚膜梭菌α毒素的一种快速、简便的检测手段．     

鞭毛蛋白毒素导致的黑松超微结构病理学变化

【目的】以松材线虫、致病细菌荧光假单胞菌及其鞭毛蛋白毒素、非致病细菌缓慢葡萄球菌等材料对3年生黑松进行接种试验,通过其样枝切片的超微结构病理学变化,了解致病细菌毒素在松萎蔫病中的作用。【方法】分别以野生松材线虫悬液、荧光假单胞菌菌株GcM5-1A无细胞滤液、无菌松材线虫+荧光假单胞菌菌株GcM5-1A、荧光假单胞菌菌株GcM5-1A的鞭毛蛋白毒素Flg、无菌松材线虫+缓慢葡萄球菌菌株AM2C、无菌松材线虫悬液接种黑松,以健康松树为对照。对于发病的处理,在接种后病程的第2或第3阶段取样; 对于未发病的处理,则在接种11 d后取样。取样时,在距离接种点不同位置进行,然后制备透射电镜样品,观察这些切片的超微结构变化。【结果】野生松材线虫、GcM5-1A无细胞滤液、无菌松材线虫+GcM5-1A、GcM5-1A鞭毛蛋白毒素等4种处理下黑松树体组织的超微结构均遭受严重破坏,病理学变化趋势一致。无菌松材线虫、无菌松材线虫+AM2C等两种处理下树体组织基本未遭受破坏,超微结构观察结果与健康松树的基本一致。GcM5-1A无细胞滤液与野生松材线虫的处理中,在靠近接种点处,前者处理下切片的超微结构受害比后者严重; 在远离接种点处,前者受害反而比后者轻。通过GcM5-1A无细胞滤液与野生松材线虫接种观察结果比较,发现松材线虫在树体内的移动加速了致病菌的扩散,导致毒素的增产和扩散,加速了松树的死亡。【结论】在接种处理的第2阶段是松萎蔫病发展的关键阶段。无菌松材线虫不能致死松树,而松材线虫携带的致病细菌产生的毒素是致死松树的真正原因,验证了松萎蔫病是松材线虫与其携带致病细菌的复合侵染导致病害的假说,而松材线虫在树体内的移动加速了致病菌的扩散,最终导致松树加速死亡。     

松毛虫质型多角体病毒悬浮剂防治马尾松毛虫田间药效实验

本实验主要研究20亿PIB/mL松毛虫质型多角体病毒悬浮剂防治马尾松毛虫田间药效.实验结果表明:松毛虫质型多角体病毒的致死速度与其剂量有关,在500倍液剂量处理区,在1周内的死亡率达到67.6％,各试剂量区均有明显的持效性.第15天的防效效果为83.5％ ～90.4％;第30天的防效为85.6％ ～95％;松毛虫质型多角体病毒1000倍液剂量与500倍液剂量区与Bt区防治效果差异显著.     

不同球孢白僵菌菌株对马尾松毛虫致病性评价

选择9个球孢白僵菌Beauveria bassiana菌株对4龄马尾松毛虫Dendrolimus punctatus幼虫进行毒力测定.结果显示,菌株Bb1900对马尾松毛虫幼虫的校正死亡率达96.16％,侵染率达86.67％,在孢子浓度为1×107孢子/mL时的半致死中时仅为4.62 d,显示出对目标害虫的较强毒力,在马尾松毛虫的生物防治中将有重要的应用价值.     

银纹夜蛾核型多角体病毒安全试验

银纹夜蛾NPV经皮擦、喷喉、滴眼、口服和脑内,皮下,静脉注射等多种途径感染小白鼠,仔鼠及家兔。口服感染鸡、羊、金鱼和家蚕。饲养7—42天,各种动物外观生长良好,体重增加,产子照常(小白鼠),活体解剖,内脏正常无异,脏器各组织切片观察细胞无病变,匀浆离心检查,均未发现NPV包含体。说明银纹夜蛾NPV特异性强,对啮齿动物、家畜、家禽、鱼类及家蚕无致病性,是一种安全有效的生物杀虫剂,可以在生产上推广应用。     

杨桃引起肾脏损伤的早期病变研究

用新鲜杨桃饲喂家兔，收集尿液化验，发现７只动物中５只发生血尿。红细胞最早见于饲喂杨桃后３８ｈ采集的尿液中。于第５天将全部动物处死，取肾脏进行光镜、电镜和免疫酶标检查，发现肾小球有炎症反应，基底膜损伤，肉眼血尿动物病变比镜下血尿和无血尿者严重。     

Adoptive transfer of EAE-like lesions from rats with coronavirus-induced demyelinating encephalomyelitis

Viruses have been found to induce inflammatory demyelinating lesions in central nervous system (CNS) tissue of both animal and man, either by natural infections or after vaccination. At least two different pathogenic mechanisms have been proposed for these changes, a cytopathic viral infection of oligodendroglia cells with subsequent cell death, and a host immune reaction against virus and brain antigens. We now report the occurrence of cell-mediated immune reactions against basic myelin proteins in the course of coronavirus infections in Lewis rats. Infection of rats with the murine coronavirus JHM leads to demyelinating encephalomyelitis developing several weeks to months postinfection. Lymphocytes from these diseased Lewis rats can be restimulated with basic myelin protein (BMP) and adoptive transfer of these cells leads to lesions resembling those of experimental allergic encephalomyelitis (EAE) in recipients, which can be accompanied by a mild clinical disease. This model demonstrates that a virus infection in CNS tissue is capable of initiating an autoimmune response which may be of pathogenic importance.     

细菌XSJS3对松材线虫杀线活性的测定

细菌XSJS3是一种新发现的对松材线虫(Bursaphelenchus xylophilus)具有较高杀线活性的细菌,试验比较了细菌XSJS3培养液、细菌培养液滤液及含菌体水溶液对松材线虫的杀线活性,结果发现细菌菌体本身对松材线虫无杀线活性,杀线活性物质存在于细菌的培养液滤液中。通过对该细菌培养液滤液对松材线虫致死过程的观察发现:松材线虫接触该细菌培养液滤液30min后就表现为行动迟缓;在5h后所有虫体均不活动,针刺无反应;24h后部分僵直虫体出现局部膨大,且膨大部位出现体液外渗而虫体最终被消解。对不同培养时间的细菌XSJS3滤液杀线活性的比较试验表明:该细菌分泌的杀线物质在10d内随培养时间的延长而含量增加,杀线活性逐渐提高,不同培养时间下滤液的杀线活性差异明显;但培养15d后,稀释10倍的滤液对松材线虫杀线活性比培养10d时同样滤液的杀线活性则略有下降,但差异不明显,因此获得该细菌分泌的杀线物质较理想的培养时间为10d。将细菌XSJS3培养液滤液进行不同温度的热处理后测定对松材线虫的杀线活性,结果表明引起松材线虫死亡和消解的物质是两个不同物质,存在于培养液滤液中的对松材线虫有杀线活性的物质是热稳定的,而引起松材线虫虫体消解的物质是热不稳定的。     

普通（一级）动物肺脏自发感染病理观察

用两个亚慢性动物试验（６４ｄ,９０ｄ）对照全的７４只Ｗｉｓｔａｒ大鼠肺脏进行病理组织学检查,发现其对环境的应激反应表现为肺内各级呼吸组织的炎症,病变较为明显的是支气管旁淋巴组织套袖样围管浸润,并浸润支气管粘膜上皮细胞,两组动物的发生率分别为８５．７１％,９２．３１％,同时肺内血管周围炎细胞浸润,肺泡隔增厚,肺内可见点状,片状炎细胞浸润灶,随着试验周期的延长,病变发生率有升高的趋势。     

基底前脑胆碱能神经元损毁:一种老年性痴呆方法学动物模型的复制及应用要点

目的介绍一种老年性痴呆的方法学动物模型-基底前脑胆碱能神经元损毁模型的复制及应用要点,以及该模型比较生物学研究的有关进展。方法采用鹅膏覃氨酸基底前脑区Maynert基底核定位注射造模,通过水迷宫实验测试动物的学习记忆能力。结果该手术方法能造成动物学习记忆能力下降,但各组内动物个体差异极大,变异系数为27.1%~46.2%。以正常动物平均成绩的95%置信区间为标准,对造模的成功率进行筛选,表明该模型的成功率为50%~75%,说明了进行模型筛选的重要意义。结论基底前脑胆碱能神经元损毁模型对老年性痴呆研究具有重要价值,但在应用中需要注意有关方法学问题。     

Meta-Analysis of Polymerase Chain Reaction in the Detection of Human Leptospirosis

Leptospirosis, a major zoonotic disease widespread in the world, would infect humans and other animals by direct contacting with the soil or water contaminated by the pathogenic leptospires. This report analyzes the accuracy of polymerase chain reaction(PCR) assay used in the detection of leptospira specific genes in humans. Seventeen published articles which included 2 526 samples satisfied all inclusion standards and were applied to meta-analysis. Pooled sensitivity and specificity were 0.73(95% CI 0.70-0.76) and 0.94(95% CI 0.93-0.95), respectively. Heterogeneity was statistically significant among studies, but none of the sources for heterogeneity(disease stage, PCR type, targeted genes) could adequately interpret this finding. Meta-regression advised that real-time PCR(qPCR) targeted 16 s rRNA would be the best choice for early detection of cases during the acute stage of the disease and was accounted as a good screening tool in all stages of the disease.     

马尔尼菲青霉病研究新发现——溶骨病变及关节炎

播散性马尔尼菲青霉病嗜侵犯单核巨噬细胞系统，主要为骨髓、肝（枯否细胞）、脾、淋巴结和肺（尘细胞），引起一系列相应病变和症状：在骨髓最常引起巨噬细胞增生性炎，并吞噬大量病原体，但却无肿痛表现；但当引起化脓性溶骨性病变和波及关节引起关节炎时则出现该病唯一的自发性疼痛。本文报告６例并复习文献发现３例有骨及关节肿痛的病例。患者为中青年人，具有较强的炎症反应能力；同时都有骨外脓肿形成，好发生于扁骨和下肢关节；病灶都能培养出马尔尼菲青霉，但病变局部病原数量较少，组织中不易找见，必须用霉菌特殊染色，用免疫酶染色找抗原则更敏感；该病治疗不彻底易复发，需长期积极抗霉菌治疗。     

A microbial symbiosis factor prevents intestinal inflammatory disease

Humans are colonized by multitudes of commensal organisms representing members of five of the six kingdoms of life; however, our gastrointestinal tract provides residence to both beneficial and potentially pathogenic microorganisms. Imbalances in the composition of the bacterial microbiota, known as dysbiosis, are postulated to be a major factor in human disorders such as inflammatory bowel disease. We report here that the prominent human symbiont Bacteroides fragilis protects animals from experimental colitis induced by Helicobacter hepaticus, a commensal bacterium with pathogenic potential. This beneficial activity requires a single microbial molecule (polysaccharide A, PSA). In animals harbouring B. fragilis not expressing PSA, H. hepaticus colonization leads to disease and pro-inflammatory cytokine production in colonic tissues. Purified PSA administered to animals is required to suppress pro-inflammatory interleukin-17 production by intestinal immune cells and also inhibits in vitro reactions in cell cultures. Furthermore, PSA protects from inflammatory disease through a functional requirement for interleukin-10-producing CD4+ T cells. These results show that molecules of the bacterial microbiota can mediate the critical balance between health and disease. Harnessing the immunomodulatory capacity of symbiosis factors such as PSA might potentially provide therapeutics for human inflammatory disorders on the basis of entirely novel biological principles.     

小麦纹枯病生防放线菌株筛选及其防效初步研究

从小麦根际和土壤中分离到161个放线菌株.经平板抑菌测定,发现有7个菌株对小麦纹枯病菌表现出较强的抑菌作用活性.菌株发酵液抑菌测定结果表明,S024菌株抑菌活性最好,菌丝生长抑制率达78.6%.室内盆栽试验S024菌株发酵液对纹枯病的防效为45.38%,田间小区防效达到63.21%,并能提高小麦种子发芽率,促进幼苗的生长.     

Immunization with amyloid-beta attenuates Alzheimer-disease-like pathology in the PDAPP mouse.

Amyloid-beta peptide (Abeta) seems to have a central role in the neuropathology of Alzheimer's disease (AD). Familial forms of the disease have been linked to mutations in the amyloid precursor protein (APP) and the presenilin genes. Disease-linked mutations in these genes result in increased production of the 42-amino-acid form of the peptide (Abeta42), which is the predominant form found in the amyloid plaques of Alzheimer's disease. The PDAPP transgenic mouse, which overexpresses mutant human APP (in which the amino acid at position 717 is phenylalanine instead of the normal valine), progressively develops many of the neuropathological hallmarks of Alzheimer's disease in an age- and brain-region-dependent manner. In the present study, transgenic animals were immunized with Abeta42, either before the onset of AD-type neuropathologies (at 6 weeks of age) or at an older age (11 months), when amyloid-beta deposition and several of the subsequent neuropathological changes were well established. We report that immunization of the young animals essentially prevented the development of beta-amyloid-plaque formation, neuritic dystrophy and astrogliosis. Treatment of the older animals also markedly reduced the extent and progression of these AD-like neuropathologies. Our results raise the possibility that immunization with amyloid-beta may be effective in preventing and treating Alzheimer's disease.