Mitogenic activation of human lymphocytes: a protein A plaque assay evaluation of polyclonal B-cell activators

Using the protein A plaque assay, the capacity of various polyclonal B cell activators to induce differentiation in human B lymphocytes was investigated. Dextran sulphate and native dextran were both virtually devoid of mitogenic properties. Lipopolysaccharide, however, was found to be a potent mitogen in human cells that, although giving rise to low DNA synthetic response, induced high numbers of immunoglobulin-synthesizing cells. Mean plaque-forming cell (PFC) numbers in healthy blood donors assayed on the optimal day (days 5-7) were 23,493 IgM/10(6) cells, 11,288 IgG/10(6) cells, and 2643 IgA/10(6) cells. Values obtained in spleen cells, peaking at days 4-6, were slightly higher. Purified protein derivative (PPD) was equally or even more effective than lipopolysaccharide (LPS) in generating PFC of different subclasses in peripheral blood with mean of 29,241 IgM/10(6), 21,269 IgG/10(6), and 3681 IgA/10(6). PPD furthermore induced a marked DNA synthetic response in human lymphocytes. These data suggest that LPS and PPD may both be used as functional markers in human cells when analysing patients with a suspected immunodeficiency state. It is suggested that cultures should be assayed using the protein A plaque assay, thereby being able not only to investigate the individual immunoglobulin classes but also to avoid the possible hazards involved in measuring antigen-specific responses in patients whose prior immunization to the antigen tested can never be totally excluded.     

A comparison of oral prostaglandin E2 and intravenous oxytocin for induction of labor in normal and high-risk pregnancies

The efficacy of oral prostaglandin E2 (PGE2) for induction of labor has been compared to that of intravenous oxytocin. There were 49 patients in each series. The over-all success rate with PGE2 is 82 per cent; with oxytocin, 65 per cent. PGE2 is at least as effective as oxytocin regardless of Bishop score or gravidity. There was no difference in the duration of labor in successful inductions with PGE2 or oxytocin. Nausea and diarrhea are more common with PGE2 but in only one case was this severe enough to warrent discontinuing the medication. One case of uterine hypertonus occurred in each series. No serious harmful effects on mother or fetus were noted with PGE2. These data support the concept that oral PGE2 administration is a safe and effective alternative to intravenous oxytocin for induction of labor in normal and high-risk pregnancies.     

Heterotrophic plate count measurement in drinking water safety management: report of an Expert Meeting Geneva, 24-25 April 2002

A group of microbiology and public health experts including regulatory and medical expertise was convened in Geneva, Switzerland, 25-26 April 2002 to consider the utility of heterotrophic plate count (HPC) measurements in addressing drinking water quality and safety. The group was convened following the NSF International/World Health Organization Symposium on HPC Bacteria in Drinking Water--Public Health Implications? The Expert Meeting was attended by 31 participants from Australia, Canada, France, Germany, Italy, Japan, the Netherlands, South Africa, Switzerland, UK and USA.     

可加热塑料食品包装中 VOCs 分析

目的分析可加热塑料食品包装中的挥发性有机物(VOCs)。方法以甲醇为溶剂,配制异丙醇、乙酸乙酯、苯、乙酸丁酯、乙苯、间/对二甲苯、邻二甲苯、环己酮的标准溶液,利用顶空/气相色谱-质谱(HS/GC-MS)技术对7种可加热塑料食品包装进行了检测分析,对比加热前后塑料食品包装中VOCs的变化。结果原味酸牛奶包装袋在加热后环己酮的含量明显增加,小酥肉塑料包装盒在加热后异丙醇的含量增加比较明显,粽子塑料包装袋、玉米塑料包装袋、奶茶塑杯、自加热饭盒、微波饭盒在加热前后VOCs含量变化不大。结论这7种包装中的苯类溶剂残留量均超标。     

点云数据曲面重构和小波分解研究

根据三坐标测量机测得的点云数据,提出了一种准均匀B样条曲面重构和小波分解方法。该方法通过对测量数据的分层、排序,自动建立了数据点的拓扑信息。为了生成矩形域网格,构造插值于扫描线上数据点的非均匀B样条曲线,再对其均匀采样,以保证曲面插值精度。对反算出的控制点网格进行小波分解后得到了多级逼近曲面。采用面向对象的编程技术,开发了相应的模块。利用写引擎把构造和分解的曲面保存为IGES文件,并直接导入商用3维CAD软件中进行后续处理。该方法具有较好的工程应用价值。     

Body Beautiful: medical aesthetics and the reconstruction of urban Britain in the 1940s

The convergence of two seemingly distinct discourses - those of medical science and planning - in the period of urban reconstruction at the close of the Second World War is discussed. It is suggested that planners in 1940s Britain conceptualized urban reconstruction by employing the visual imagery and rhetoric of contemporary 'medical aesthetics'. The convergence of these ideas was purposeful: medical knowledge and its newly emerging aesthetics transplanted itself easily into the imaginative realms of urban reconstruction so that planners and architects alike could visualize the social, moral and architectural improvements to be made to the city in terms of diagnosis, cure and treatment. Reconstruction was not simply building cities anew; it also involved a vision of post-war life in its full cultural complexity.     

发酵过程中啤酒酵母生长代谢活性的电化学分析

首次报道了电化学分析方法在 4 80t啤酒酵母发酵过程中对酵母细胞生长代谢的连续检测。从 0代到 4代 ,从满罐到降温结束 ,跟踪了 5代酵母发酵的全过程。研究表明 ,电化学方法可以描述细胞生长代谢的过程 ,反应细胞的代谢活性 ,在相应地细胞生长代谢阶段 ,细胞的电化学活性与细胞数有良好的线形关系。因此细胞电化学方法为酵母发酵过程提供了一个快速、准确的细胞代谢过程及代谢活性的分析方法