Use of adsorbed diphtheria-tetanus (DT) toxoid containing different doses of antigens in booster immunizations of children

To decrease the antigenic load in booster immunizations of children against diphtheria and tetanus, the immunological effectiveness and reactogenicity of different doses of both antigens (i. e 1 Lf and 1 BU; 2.5 Lf and 2.5 BU; 5 Lf and 5 BU) were studied. The study revealed that all these doses of the preparation were practically nonreactogenic: the total of systemic reactions was 0.9%. The study of the immunological effectiveness of adsorbed DT toxoid with reduced antigen content revealed the advantage of the commercial dose of the preparation (5 Lf of diphtheria antigen and 5 BU of tetanus antigen) over such doses of diphtheria and tetanus antigens as, respectively, 1 Lf and 1 BU; 2.5 Lf and 2.5 BU. Still, this advantage disappeared as early as 6 months after booster immunization. The results of these investigations indicate that booster immunization of children aged 6 years and over may be made with lower doses of adsorbed DT toxoid with reduced antigen content.     

生物医学工程的精要、责任和展望

作为工程学的直属分支,建立生物医学工程学科的主要目的不是为了开辟一个新的科学研究领域,而是为了借助工程学的方法来解决生物医学领域所面临的实际问题,以及借助工程师们所接受的专业训练、所拥有的专业知识、所具备的工作技巧来提高医疗服务的质量和效果。工程学与生物医学的结合已取得了一些具有里程碑性质的成果。在中低收入国家,例如中国,生物医学工程有责任保证合理使用专业技术,为低廉、可靠、有效的医疗服务提供支持。本文将根据可预见和不可预见的学科发展限制和困难,对学科发展的现实目标和责任进行严肃、冷静地讨论。     

APPLIED ISSUES: Effects of habitat rehabilitation on brown trout (Salmo trutta) in boreal forest streams

1. Degradation of stream habitat because of anthropogenic activities (e.g. channelisation) has had a dramatic impact on fluvial environments and their biota, and as a consequence, increasing effort has been directed towards the restoration of degraded rivers. However, a major problem is that the success (or failure) of restoration has been rarely tested using a well‐designed monitoring programme to allow reliable detection of an impact, if any exists. We used a spatially and temporally replicated, balanced Before‐After‐Control‐Impact design to assess the impact of stream habitat rehabilitation on the densities and growth of brown trout of three age‐classes in North Finnish forest streams. 2. Three separate sections in each of six streams were selected for the study. After 3 years of pre‐rehabilitation monitoring, two randomly selected sections in each stream were restored; one using large woody debris and boulders and the other using only boulders. A third section remained as an unmodified control. Monitoring of fish densities continued for 3 years after rehabilitation. 3. Rehabilitation clearly increased streambed complexity, but did not have detectable effects on brown trout stocks in either of the rehabilitation schemes (LWD or stones), except for age‐2+ and older fish which decreased in abundance compared to control reaches. A severe drought after rehabilitation in late summer 2002 reduced densities of trout to a low level in all streams, overriding any local effects of rehabilitation. Rehabilitation structures seemed to provide some safeguard against drought for age‐2 and older, but not for the younger age‐classes. 4. Our results add to the growing body of literature suggesting that large‐scale regional factors may overwhelm local management efforts. To be successful in the future, stream rehabilitation schemes must include drought refuge areas for fish and other stream biota.     

Correlation between the rate of protein and nucleic acid synthesis and the intensity of various glucose metabolic pathways in rat liver cells

A sharp and strong suppression of protein synthesis by cycloheximide in liver cells of starving rats is paralleled with activation of RNA synthesis and glucose-6-phosphate dehydrogenase production. Subsequent reconstitution and stimulation of protein synthesis (6-12 hrs after cycloheximide injection) result in activation of hexokinase. Upon stimulation of DNA synthesis (48-60 hrs after cycloheximide injection) the activity of both enzymes is very low. Since glucose-6-phosphate dehydrogenase appears to be the limiting step of glucose decay via the pentose phosphate pathway, and hexokinase is the limiting step of glycolysis, it was assumed that RNA synthesis predominantly occurs via the pentose phosphate pathway, while that of proteins via glycolysis.