The role of specific immunoglobulins in antibody-dependent cell-mediated cytotoxicity assays during Babesia bovis infection

A stabilate prepared from Babesia bovis-infected Boophilus microplus ticks was used to infect intact adult cattle. Whole sera and immunoglobulin fractions from representative sera were tested by complement fixation (CF), indirect fluorescent antibody (IFA), and antibody-dependent cell-mediated cytotoxicity (ADCC) assays. The last test utilized 51Cr-labeled chicken erythrocytes coated with Babesia bovis antigen as targets. Mononuclear cell preparations, obtained from peripheral blood of normal donors and consisting of lymphocytes with 2--6% large monocytes, were used as the source of effector cells. Antibody activity was detected by all tests between 14 and 16 days following infection. Specific IgM and IgG1 were reactive in both CF and IFA tests, although the development of high titers was attributable to IgG, alone. The ADCC activity was restricted to IgG1 fractions and was greater in those sera or fractions with greater CF activity. No activity was demonstrated in IgG2 fractions by any test used.     

河豚毒素检测原理与发展趋势

综述了河豚毒素检测原理与发展趋势,提出了采用化学反应建立河豚毒素快速筛选技术供现场监督检测用;采用GC/MS等建立河豚毒素确证检测方法供实验室监督检测用。     

7种杀菌剂对金钱树疫病病原菌的室内毒力测定

采用室内生长速率法测定了7种杀菌剂对金钱树疫病病原菌棕榈疫霉(Phytophthora palmivora Butler)的抑制作用.结果表明:0.15%四霉素水剂的抑制效果最好,EC50值为0.0457μg/mL,EC90值为0.2174μg/mL;其次为6.25%精甲·咯菌腈悬浮种衣剂和50%烯酰吗啉水分散粒剂,抑菌效果显著,前者的EC50值为0.0758μg/mL,EC90值为2.4683μg/mL,后者的EC50值为0.3407μg/mL,EC90值为2.0794 μg/mL;22.7%二氰葸醌悬浮剂、80%代森锰锌可湿性粉剂和50%氟码·乙铝可湿性粉剂对菌丝生长也有一定的抑制作用,其EC50值分别为0.1382 μg/mL、2.3796μg/mL和5.4602μg/mL;72.2%霜霉威盐酸盐水剂的抑制效果最差,EC50值为498 μg/mL.在供试的7种杀菌剂中,性价比以80%代森锰锌可湿性粉剂最高,其次为50%烯酰吗啉水分散粒剂.     

农业高职院校实验室废弃物的危害与处理

随着高职院校办学规模的扩大,学生人数的增加,实验室产生的废弃物越来越多,若处理不当将引起二次传染和环境污染,危害人们身体健康。加强对农类高职院校实验室废弃物分类、危害的认识和重视,并对实验室废弃物进行科学处理,有利于疾病的预防与控制、实验室建设和环境保护。     

Pup mortality in laboratory mice – infanticide or not?

Background

Despite being the most commonly used mammal in biomedical research, problems with perinatal mortality in mice have received little attention and the causes of pup death are still poorly known. Females are often housed alone with their litters and since the lost pups are generally eaten, it is commonly assumed that the mother has killed them. However, more detailed observations than have been reported previously in the literature are required to establish if the cause of death is infanticide. Litter loss can only be prevented efficiently after underlying causes have been carefully investigated and interpreted. The aim of this study was to investigate if females actively kill their pups by observing the behaviour of females and pups in litters that later were lost. We used video recordings of females that lost their entire litter to observe females in detail from parturition until the pups died. In total, 10 C57BL/6 females (wildtype and the knockouts Hfe^−/− and β2m^−/−) were studied, housed in Makrolon II cages with or without access to a small amount of nesting material.

Results

Three of the females had pups that were never seen moving, and another three females had one or two pups that never moved, indicating that some pups were most likely still-born. In five females with live-born pups, detailed observations from the time when a pup was last seen moving until it died were possible to carry out. We observed females eating dead offspring and interacting with both moving and dead pups. However, we never observed a pup stop moving when manipulated by the female, nor were any wounds seen in the pups. Hence, we found no evidence of infanticide when studying females that had lost their entire litter.

Conclusion

These results suggest that other causes than infanticide plays a major role in mouse pup death, and stress the need for more systematic and careful investigations of the causality of litter loss.     

Composition and biological activity of the essential oil from Thapsia minor, a new source of geranyl acetate

The essential oils from aerial parts of Thapsia minor Hoffmanns. & Link (Apiaceae), obtained by hydrodistillation, were analyzed by gas-chromatography and gas-chromatography-mass spectrometry. Oxygenated monoterpenes represented the main fraction with geranyl acetate (82.3-83.0%) as the major constituent, making this plant a good source of this compound.Biological activity of the essential oil was evaluated against several fungal strains. The highest activity was found against dermatophyte strains, Crytococcus neoformans and Candida guillermondii with minimal inhibitory concentrations values from 0.32 μl/ml to 1.25 μl/ml. The antifungal activity could be associated with the significant contribution of the oxygenated monoterpene geranyl acetate.Furthermore, this essential oil demonstrated to have potent anti-inflammatory in vitro activity, at concentrations that did not affect macrophages and keratinocytes viability, being the anti-inflammatory properties of the oil mainly due to geranyl acetate.These favorable results emphasize the antifungal and anti-inflammatory abilities of the molecule geranyl acetate and further support the exploitation of T. minor oil for pharmaceutical industry, in order to find new phytopharmaceuticals.     

农业转基因实验室生物风险研究进展

综述了我国农业转基因实验室生物安全研究的现状以及转基因作物实验室的生物安全风险因素,并提出了相应的安全管理建议。     

农业科研实验室规范化管理的探讨

随着实验室规模和层次的不断提升,实验室评估、分中心建设工作的广泛开展,加快实验室规范化管理已显得十分重要。实验室规范化管理主要包括实验室组织机构管理、设施和环境管理、技术人员管理、仪器设备管理、化学药品管理、档案管理等内容。本文就如何进行农业科研实验室的规范化管理问题进行了有益的探讨。     

运行中SPF级动物实验室环境指标的监测与分析

[目的]观察运行中SPF级大小鼠动物实验室的环境指标,以指导科学试验和设施管理。[方法]在不同季节、不同动物饲养量和不同管理情况下,按国家标准GB14925-2001测试相关环境指标。[结果]运行中SPF级动物实验室的各项指标稳定,全年温度21～24℃,相对湿度40%～67%,换气次数14.4～17.2次/h,空气洁净度6000～12000级,梯度压差19.8～31.6Pa,噪声37.2～45.0dB,菌落数1.0～2.1个/皿,氨浓度3.2～4.5mg/m^3。[结论]不同季节大气尘浓度的变化对SPF级动物实验室的环境指标无影响,严格管理可保持动态动物实验室的洁净度。     

实验室生物安全问题及其防护建议

阐述了生物安全的基本概念与内涵,并主要就实验室生物安全问题及其防护策略等方面进行了探讨,以期为我国实验室生物安全防护提供有益参考。