An attempt at embryo transfer as a means of controlling Bordetella bronchiseptica infection in the rabbit

Embryo transfer was attempted in order to control disease in rabbits. Embryos were collected by flushing of the oviducts of donor rabbits on Day 2 of gestation, into small tubes containing the medium, transported within the body warmth of the person carrying the tubes and transferred into the oviducts of SPF pseudopregnant recipients. The time between embryo collection and transfer was 7-8 hours. Ten of 56 embryos derived from Bordetella bronchiseptica infected animals developed into newborns. As a result of bacteriological examination of intranasal exudate in six weanlings, no pathogens were detected. We suggest that embryo transfer is an effective and simple alternative to caesarean operation in Bordetella bronchiseptica infected rabbits.     

Digest this! A role for autophagy in controlling pathogens

Autophagy provides a mechanism for cells to conserve nutrients, but was recently associated with immunity to intracellular pathogens. Here, Zhao et al. (2008) present direct in vivo evidence that autophagy is linked to macrophage control of Toxoplasma gondii and Listeria monocytogenes and highlights that this process intersects with cytokine-mediated antimicrobial responses.     

桑天牛对补充营养寄主的选择性及诱杀药剂筛选

桑天牛Apriona germari(Hope)对补充营养植物的偏好性引起了诸多学者的广泛关注。利用天牛对寄主植物的选择性,开发植物源引诱剂对于天牛的控制具有重要意义。作为植物源引诱剂开发的一个基础工作,本论文研究选择3种主要寄主植物(构树、桑树和杨树)进行桑天牛成虫选择性与取食量的研究;研究显示,构树(Broussonetia parpyrifera(L.)Vent)、桑树(Morus alba L.)和杨树(Populus×canadensis Moench)引诱桑天牛成虫补充营养频率存在显著差异(F=118.9,P<0.01),桑天牛成虫补充营养对于构树具有极明显的选择性;桑天牛对3种植物取食量存在显著差异(F=14.7,P<0.01),桑天牛成虫补充营养时对构树具有明显的偏好性。上述研究为桑天牛成虫诱集捕杀及其引诱剂开发奠定理论基础。同时,为了更好的指导生产实践,本文对两种杀虫剂——虫线清乳油与绿色威雷(触破式微胶囊剂)毒杀桑天牛的效果进行了评价。试验采用林间罩笼方法,测定了两种杀虫剂对桑天牛成虫效果。研究结果表明,虫线清喷施后,显著抑制了桑天牛的取食行为;5 d内桑天牛成虫全部死亡,防治率为100%;绿色威雷喷雾防治桑天牛成虫杀虫作用迅速,150 min内成虫全部死亡,防治效果达100%。上述两种药剂可以作为桑天牛成虫诱集捕杀的候选药剂在生产实践中加以应用。     

Epidemiological and immunological study of the foci of measles infection

Anamnestic data in respect to measles failed to correspond to the results of serological examination of contacts at the foci of the given infection. The collective immunity level in children's institutions is inadequate for the prevention of measles outbreaks. The incidence of the disease depended both on the level of immunity among the children and on the duration of presence of the source of infection in the focus. Live measles vaccine protected 90 percent of the vaccinated children from contracting the disease in the foci. At the very beginning of the postvaccinal period immunization defects were revealed in 26.5 percent of the vaccinated children who fell ill with measles. Morbidity index among the vaccinated individuals constituted 3.8 percent. One of the causes of measles contraction by the vaccinated individuals was the loss of postvaccinal immunity. Systematic control over the antimeasles immunity level with the aid of serological investigations is necessary for the purpose of detection of persons sensitive to measles in children's collective bodies.     

Epidemiological characteristics of meningococcal infection in Cuba

The results of the epidemiological analysis of the morbidity rate in meningococcal infection for 1976-1984 are presented. The maximum rise of morbidity rate, equal to 14.4 per 100000 of population, was observed in 1983. Primarily, the rise of morbidity rate in 1979 was induced by meningococci of two serogroups: C (44.6%) and B (36.4%). The vaccinal prophylaxis of the population, carried out in 1979 with the use of polysaccharide vaccine A + C, did not affect morbidity caused by group B meningococci. The isolation rate of these organisms reached 98.7% from patients and 81.0% from carriers. The characteristic feature of the epidemic process of meningococcal infection in Cuba was a considerable increase in the number of patients under 1 year of age and the absence of seasonal fluctuations in morbidity rate.     

对一起诺如病毒感染疫情的流行病学调查分析

分析一起发生在某幼儿园的诺如病毒暴发疫情,为预防预警此类事件提供科学参考依据。采用现场流行病学调查的方法描述疫情的发生过程、三间分布、临床特征、确认检验。采集相关人员肛拭子标本、可疑食物、剩余食品、餐具样品、饮用水样本等,开展有效的实验室检测。在搜索的34例病例中,临床诊断病例为29例,实验室确诊病例为 5例,隐性感染者16例,罹患率为16.59 %,无重症和死亡病例。病例分布在各楼层的5个班级,年龄2-5岁之间。症状主要为呕吐(100%)、腹泻(23.52%)、恶心(55.88%)、腹痛(58.82%)、发热(67.65%)。实验室检验结果为诺如病毒GII型和GI型、GII型混合,常见肠道致病菌均为阴性。依据《诺如病毒感染暴发调查和预防控制技术指南(2015版)》,结合流行病学调查资料、病例临床表现及实验室检测结果,研判本起事件为人员交叉感染诺如病毒引起的暴发性疫情。加强对幼儿园全方位管理、开展相关健康教育宣传和防控培训,对有效预防和减少类似疫情的发生尤为重要。     

大亚湾生态环境问题及其调控策略

主要阐述了大亚湾现存的生态环境问题及其调控策略.大亚湾生态环境的退化现状与特征主要表现为:生态系统结构遭到破坏、生物群落组成明显小型化,生物多样性降低,生物资源衰退;红树林和珊瑚礁面积锐减,生态服务功能衰退,沿岸滨海湿地萎缩;生物生境遭破坏导致生物量下降;营养环境恶化导致赤潮频发.并就因开发建设等人类活动对该区域海洋生态环境的影响,提出了调整和控制各种开发活动,为受损海湾生态环境的修复重建和持续利用的参考建议.     

Good manufacturing practices — A means of controlling biodeterioration

Control of biodeterioration and all aspects of product or operational safety depend upon good manufacturing practices and one of the most effective methods which has been developed to ensure this is by hazard analysis of critical control points (HACCP). This is an all embracing philosophy which examines the risk of microbiological biodeterioration from both the survival of spoilage micro-organisms to processing conditions or contamination at all stages of manufacture, and builds in the relevant quality assurance standards and processing specifications to minimise the risk of biodeterioration of the product and does not rely solely upon the analysis of the finished product. For manufacturers this requires knowledge and control of the microbiological quality of the raw materials, packaging components and processing environment; a validation of the ability of any in-process stages to destroy both pathogenic or spoilage micro-organisms and the effectiveness of the preservative system throughout the shelf-life of the product.