ADP-ribosyltransferase activity of pertussis toxin and immunomodulation by Bordetella pertussis

Pertussis toxin is produced by the causative agent of whooping cough, Bordetella pertussis, and is an adenosine diphosphate (ADP)-ribosyltransferase capable of covalently modifying and thereby inactivating many eukaryotic G proteins involved in cellular metabolism. The toxin is a principal determinant of virulence in whooping cough and is a primary candidate for an acellular pertussis vaccine, yet it is unclear whether the ADP-ribosyltransferase activity is required for both pathogenic and immunoprotective activities. A B. pertussis strain that produced an assembled pertussis holotoxin with only 1 percent of the ADP-ribosyltransferase activity of the native toxin was constructed and was found to be deficient in pathogenic activities associated with B. pertussis including induction of leukocytosis, potentiation of anaphylaxis, and stimulation of histamine sensitivity. Moreover, this mutant strain failed to function as an adjuvant and was less effective in protecting mice from intracerebral challenge infection. These data suggest that the ADP-ribosyltransferase activity is necessary for both pathogenicity and optimum immunoprotection. These findings bear directly on the design of a nontoxic pertussis vaccine.     

Vaccinia virus: a tool for research and vaccine development

Vaccinia virus is no longer needed for smallpox immunization, but now serves as a useful vector for expressing genes within the cytoplasm of eukaryotic cells. As a research tool, recombinant vaccinia viruses are used to synthesize biologically active proteins and analyze structure-function relations, determine the targets of humoral- and cell-mediated immunity, and investigate the immune responses needed for protection against specific infectious diseases. When more data on safety and efficacy are available, recombinant vaccinia and related poxviruses may be candidates for live vaccines and for cancer immunotherapy.     

Rationale for development of a synthetic vaccine against Plasmodium falciparum malaria

Protective immunity against malaria can be obtained by vaccination with irradiated sporozoites. The protective antigens known as circumsporozoite (CS) proteins, are polypeptides that cover the surface membrane of the parasite. The CS proteins contain species-specific immunodominant epitopes formed by tandem repeated sequences of amino acids. Here it is shown that the dominant epitope of Plasmodium falciparum is contained in the synthetic dodecapeptide Asn-Ala-Asn-Pro-Asn-Ala-Asn-Pro-Asn-Ala-Pro or (NANP)3. Monoclonal antibodies and most or all polyclonal human antibodies to the sporozoites react with (NANP)3, and polyclonal antibodies raised against the synthetic peptide (NANP)3 react with the surface of the parasite and neutralize its infectivity. Since (NANP)3 repeats are present in CS proteins of P. falciparum from many parts of the world, this epitope is a logical target for vaccine development.     

Efficacy of murine malaria sporozoite vaccines: implications for human vaccine development

As part of a study of potential vaccines against malaria, the protective efficacy of sporozoite subunit vaccines was determined by using the Plasmodium berghei murine malaria model. Mice were immunized with recombinant DNA-produced or synthetic peptide-carrier subunit vaccines derived from the repetitive epitopes of the Plasmodium berghei circumsporozoite gene, or with radiation-attenuated sporozoites. Immunization with subunit vaccines elicited humoral responses that were equivalent to or greater than those elicited by irradiated sporozoites, yet the protection against sporozoite challenge induced by either of the subunit vaccines was far less than that achieved by immunization with attenuated sporozoites. Passive and adoptive transfer studies demonstrated that subunit vaccines elicited predominantly antibody-mediated protection that was easily overcome whereas irradiated sporozoites induced potent cell-mediated immunity that protected against high challenge doses of sporozoites. These studies indicate that new strategies designed to induce cellular immunity will be required for efficacious sporozoite vaccines.     

中国适宜于非粮能源植物生产的土地概念、分类和发展战略

当前社会不允许错失生物质能源减排温室气体和促进地区能源、环境与社会发展天赐良机,也不能接受其对粮食安全、生态环境和社会发展的任何不良影响。本研究在总结能源植物土地利用坚持非粮和生态保护原则的基础上,首先分析了我国当前土地利用与保障粮食安全的关系,认为大量土地撂荒、闲置和污染表明能源植物生产用地前景广阔。其次论证了我国应确立"以粮为纲、粮能并举"的土地利用方针,优化土地管理,实现土地集约利用,走保障粮食安全、发展能源和保护生态的多赢路线。最后确定了适宜于中国国情的可用于种植能源植物土地(宜能非粮地)的定义,讨论了宜能非粮地的污染超标、撂荒闲置、低等级、未利用、多用途增值和自然系统等非粮特征,将其分为宜能非粮耕地、宜能园地、宜能林地、宜能荒草地、宜能交通运输绿化用地、宜能水域和水利设施用地和其他未利用宜能土地等7大类。据此建议进一步研究土地利用的非粮和宜能的相关具体指标,以确定宜能非粮地的分级、面积和分布。     

动物寄生虫基因工程疫苗的研究进展

由于长期使用化学药物导致了动物寄生虫的抗药性、药物残留和环境污染等一系列问题，而基因工程疫苗具有安全、无药物残留和无环境污染等优点，本文简述了寄生虫基因工程疫苗的研究进展．     

当归适宜栽培化学除草剂筛选

对适宜当归栽培的化学除草剂进行筛选,结果表明:适宜当归地的除草剂为敌草胺、扑草净及2种除草剂混合处理;当归实生苗和1年生苗地适宜处理剂量为敌草胺2 kg/hm2 扑草净2 kg/hm2(有效含量:敌草胺50%,扑草净40%);当归实生苗和1年生苗地的最佳茎叶处理剂为拿捕净,剂量为1.5 L/hm2(有效含量:12.5%).     

转变教育思想观念,树立适应时代发展的人才质量观

结合多年来建筑工程预算课程教学的理论与实践,探讨了新形势下如何转变和更新教育思想观念、树立适应时代和社会发展的人才质量观,并提出本科教育过程中的人才培养要主动适应社会发展需要的教学思路.     

大球盖菇菌种培养基筛选试验

大球盖菇(Stropharia rugoso-annulata)又名酒色球盖菇、皱环球盖菇，是联合国粮农组织(FAO)向发展中国家推荐的新菇种，也是国际菇类交易市场上的十大品种之一。该菇原产欧美，上世纪80年代末90年代初引入我国，现福建、浙江等地已有小规模栽培，四川近年才有零星种植，市场上鲜有产品面市。     

适合鞭毛染色的新菌株

从酵母培养物中分离出一株运动性极强的细菌,命名为９５０６菌株、该菌株革兰氏染色为阴性,鞭毛周生,每个菌体着生１２－２０根鞭毛,鞭毛 大,地着色,在ＰＤＡ斜布上培养１２－４８ｈ能乍到完整的鞭毛,染色液存放２周不影响鞭染色效果,其效果明显优于大肠杆菌、枯草杆菌等菌株,是一株理想的鞭毛洒色实验教学用菌株     

长根奥德蘑菌种培养基筛选试验

对两个长根奥德蘑菌株在4种不同母种和原种培养基上的菌丝生长速度及生长势作比较的结果表明,在马铃薯综合培养基上生长速度最快(6.8mm/d),生长势(菌丝雪白、菌落浓厚、菌丝均匀整齐、紧密)最佳,可作为菌株母种繁殖的首选配方.原种培养基(杂木屑39%、菌糠49%)的菌丝生长速度最快(3.0*#mm/d),可作为制备原种和栽培种的最佳培养基.     

双功能木霉突变菌株的筛选和功能分析

研究从木霉菌REMI突变株中筛选到16株对氰化物具有明显降解活性,将其与5种常见病原菌对峙培养,得到7株拮抗性较高的突变株。对这7株转化子进行盆栽试验表明:多数供试转化子对黄瓜幼苗枯萎病具有明显的防效,其中转化子TkA8的防治效果最好,达到了73.5%。同时研究发现TkA8处理黄瓜幼苗可诱导防御反应相关酶系PAL、POD活性明显增加,分别为对照的3.21和4.25倍。因此TkA8是一种具有防病和生物修复氰化物污染的较理想的多功能木霉菌株。     

动物布鲁氏菌病疫苗的来历及亚单位疫苗的研究概况

布鲁氏菌病是一种严重危害人和动物健康的人畜共患病,人群感染主要来源于感染的动物及被污染的畜产品,目前疫苗免疫仍是控制动物布鲁氏菌病的主要措施。现有国际参考疫苗主要有牛种疫苗株S19和羊种疫苗株Rev.1,这些疫苗为动物群布鲁氏菌病控制提供重要保障的同时也存在关键的技术瓶颈问题,如安全性差,接种动物出现流产;血清抗体体内持续时间较长,干扰常规诊断等。随着布鲁氏菌基因组测序工作的相继完成及DNA重组技术的发展,新型布鲁氏菌病疫苗的开发成为研究的热点。亚单位疫苗本着其较高的安全性和有效性,在动物群布鲁氏菌病控制过程中具有较大的应用前景。笔者综述了布鲁氏菌病疫苗的发展史,并对布鲁氏菌病亚单位疫苗的研究进展进行概述。     

黔西县适宜烤烟品种筛选研究

为筛选适宜在黔西县种植的烤烟品种,促进烟叶产业可持续发展,选用近年育成的贵烟201等10个品种,测定其植物学、农艺、经济和品质等性状,采用灰色关联度分析法进行综合分析。结果表明:贵烟201、贵烟202、PVH1452、毕纳1号的株高、节距、茎围适宜,顶叶开片好;贵烟201的经济性状最好,产值达55169.34元/hm~2,其次是贵烟202、毕纳1号和贵烟4号,均显著优于对照品种K326;金海1号、贵烟202、贵烟201的化学成分含量和协调性略优于对照;云烟110、云烟87、金海1号的感官质量优于对照品种。灰色关联度分析结果表明:贵烟201(0.8835)、KRK26(0.8835)和贵烟202(0.8524)的综合表现明显优于对照品种K326(0.7891)和云烟87(0.7621);贵烟4号(0.8068)和毕纳1号(0.8032)的综合表现略优于对照。可见,贵烟201、KRK26、贵烟202适宜在黔西县示范推广,贵烟4号、毕纳1号宜进一步进行较大面积的示范验证。     

适合澳洲坚果间套作的菠萝品种筛选

为筛选适合澳洲坚果(Macadamia ternifolia F. Muell.)幼龄果园间套种的菠萝[Ananas comosus(Linn.)Merr.]品种,利用随机区组设计,对台农16号、台农17号、金菠萝、台农4号4个优良菠萝品种进行试种试验,调查植株农艺性状、果实性状及品质,并进行相关性分析。结果表明,在澳洲坚果幼龄果园下套种,台农16号菠萝植株高度、叶片宽度、平均单果重、可溶性固形物含量、可溶性糖含量均最高,果肉纤维少,质地嫩滑,风味清甜。综合评价,台农16号是作为澳洲坚果间套种的最适菠萝品种。     

春小麦适期早播的重要性

简述了春小麦适期早播的重要性,包括早春温度上升快,小麦根系生长好,利于形成壮苗与早分蘖,利于小麦成穗,并增加穗粒重,小麦生长后期可减少高温干旱天气的影响,从而提高产量。     

犬细小病毒蜂胶灭活苗的制备及治疗用卵黄抗体的研制

将犬细小病毒(CPV)的弱毒苗接种于单层F81细胞上,大量增殖病毒,并制成CPV蜂胶灭活苗.其后对蛋鸡进行连续3次免疫,定期收集鸡蛋,提取蛋黄中的卵黄抗体(IgY).应用ELISA方法检测CPV卵黄抗体效价,结果表明,通过本方法能获得稳定的犬细小病毒卵黄抗体,10 d后抗体水平维持在1:320以上.     

Low-noise, interference-resistant amplifier suitable for biological signals

Minor changes in conventional low-noise amplifier circuits decrease circuit noise and attenuate the unwanted effects of varying impedances and potentials which exist between commonly employed electrodes and the tissues of biological subjects. The resulting reduction of intrinsic amplifier noise and reduced susceptibility to external interference is helpful in the study of low-frequency signals of microvolt level.     

Research and development of a novel subunit vaccine for the currently circulating pseudorabies virus variant in China

Pseudorabies (PR) is a devastating viral disease which leads to fatal encephalitis and respiratory disorders in pigs. Commercial gE-deleted live pseudorabies virus (PRV) vaccine has been widely used to control this disease in China. However, the new-emerging variants of PRV compromises the protection provided by current vaccines and lead to the outbreak of PR in vaccinated pig herds. Several killed and live vaccine candidates based on current PRV variants have been reported to be effective to control the disease. A subunit vaccine based on gB protein, one major PRV glycoprotein which elicits strong humoral and cellular immune responses, however, was never evaluated for protection against the current circulating PRV variants. In this study, full-length PRV gB protein was successfully expressed in baculovirus/insect cells in the soluble format and was tested on 3-week-old piglets as a subunit vaccine. Compared with unvaccinated pigs, the gB-vaccinated pigs developed specific antibody-mediated responses and were protected from the virulent PRV HN1201 challenge. All vaccinated pigs survived without showing any PRV-specific respiratory and neurological signs, but all unvaccinated pigs died within 7 days after HN1201 challenge. Hence, this novel gB-based vaccine could be applied as an effective subunit vaccine to control PRV variant in China.