中缝隐核投射至中脑导水管周围灰质腹侧部的递质分析

实验在戊巴比妥钠麻醉大鼠上进行。双侧中脑导水管周围灰质腹侧部（ｖＰＡＧ）微量注射１μｇ／μｌ肾上腺素（每侧０．１μｌ）,刺激中缝隐核（ＮＲＯ）引起的降压反应明显增强,但该效应可被ｖＰＡＧ预先注射心得安所阻断,而注射酚妥拉明对上述效应无明显影响;ｖＰＡＧ内单独微量注射１μｇ／μｌ心得安（每侧０．１μｌ）,可部分阻断ＮＲＯ降压反应,而注射１μｇ／μｌ酚妥拉明（每侧０．１μｌ）无明显影响;双侧ｖＰＡＧ微量注射１０μｇ／μｌ吗啡或０．１ｍｏｌ／Ｌ５－ＨＴ（每侧０．１μｌ）,基础血压无明显变化,ＮＫＯ的降压反应幅度减小（Ｐ＜０．０５）。提示,ＮＫＯ对ｖＰＡＧ的兴奋作用的可能递质为肾上腺素,通过β受体介导;吗啡或５－ＨＴ则可减弱ＮＲＯ对ｖＰＡＧ的兴奋性投射作用。     

盐胁迫下丛枝菌根真菌对玉米水分和养分状况的影响

在ＮａＣｌ胁迫下无论接种ＡＭ真菌与否玉米植株生物产量均减少,但不接种处理的减少幅度比较种处理的高１０个百分点左右,盐胁迫下接种ＡＭ真菌的玉米根系和地上部的干重、叶片水热均高于不接种处理、叶片脯氨酸含量低于不接种处理,在盐胁迫下真菌菌丝对玉米植株营养的贡献由４５．３％降为４２．６％,ＡＭ真菌对植株生长的效应反而由３０．９％提高到６３．５％,说明ＡＭ真菌主米耐盐性的机理与改善植株的水分状况和Ｐ营养状况     

雨堡组织培养的研究

取雨堡当年生的枝条上饱满的未萌发的侧芽为外植体,培养于ＭＳ培养基上,其中附加各种不同种类及浓度的激素。在附加６—ＢＡ１．０ｍｇ／ｌ的ＭＳ培养基上,诱导芽的效果最好;在附加６—ＢＡ１．０＋ＮＡＡ０．０５＋ＺＴ０．１ｍｇ／ｌ的ＭＳ培养基上,芽的增殖效果最佳;在附加ＫＴ０．３＋ＮＡＡ０．０５＋ＺＴ０．１ｍｇ／ｌ或６—ＢＡ０．３＋ＮＡＡ０．０５＋ＺＴ０．１ｍｇ／ｌ的ＭＳ培养基上,最有利于壮苗;在１／２ＭＳ培养基中,附加ＩＢＡ０．５＋ＮＡＡ０．３ｍｌ／ｌ或ＩＡＡ０．５＋ＮＡＡ０．３ｍｇ／ｌ的培养基中,生根效果最佳。试管苗高２—３ｃｍ,且具有４—８条短根时,开瓶煅炼３—５天,移入培养土中生长的效果好,种植在保温保湿环境中,试管苗成活率高。     

钾和菊酸钠诱导的离体黄瓜子叶生根过程中内源IAA和ABA含量变化

１３．４ｍｍｏｌ／Ｌ ＫＣｌ和０．６ｍｍｏｌ／Ｌ的菊酸钠诱导离体黄瓜子叶生根过程中,子叶中内源ＩＡＡ含量明显增加,菊酸钠处理的增加趋势高于ＫＣｌ处理;ＡＢＡ含量则显著下降,ＫＣｌ和菊酸钠处理的分别在２４ｈ和８ｈ达到最低,各处理的ＩＡＡ／ＡＢＡ值均明显增加。     

30L生物反应器连续灌注培养重组CHO—C28细胞表达HBsAg的研究

应用３０ Ｌ生物反应器和微载体悬浮 培养技术,通过电脑全自动控制,连续灌注培养分泌ＨＢｓＡｇ 的重组ＣＨＯ－Ｃ２８细胞。试验了培养方式、连续灌流速度,反应器转速和细胞对葡萄糖消耗等工艺条件。观察培养６０ 天,细胞的生长形态、ＨＢｓＡｇ 分泌动态和染色体数。研究结果表明,连续培养６０ 天,细胞密度可达７．０×１０６ｃｅｌｌｓ／ｍ ｌ,平均维持在（５．０～６．０）×１０６ｃｅｌｌｓ／ｍ ｌ,收液的ＲＰＨＡ 滴度可达１∶５１２,ＨＢｓＡｇ 每天平均产量为３０ ｍ ｇ。     

大花蕙兰的快速繁殖技术研究

应用组织培养和快速繁殖技术对大花蕙兰开展了茎尖培养、试管苗微繁和成苗培育的研究,结果表明,有利于原球茎增殖的培养基为ＭＳ＋６ＢＡ１．０ｍｇ／ｌ＋ＮＡＡ０．５ｍｇ／ｌ＋２％～３％蔗糖;有利于原球茎分化的培养基为ＭＳ＋６ＢＡ０．４ｍｇ／ｌ＋ＮＡＡ０．２ｍｇ／ｌ＋２％～３％蔗糖。四年生以上试管苗可以开花,为其大规模工厂化育苗提供了科学的依据。     

中国云南发现珍稀濒危树蕨巨大古树——屏边桫椤

屏边桫椤新种当地名：多头树蕨、树蕨王图１：１～８图版１：１～４ＡｌｓｏｐｈｉｌａｐｉｎｇｂｉａｎｉｃａＹ．Ｋ．Ｙａｎｇ．Ｙ．Ｍ．ＨｅｅｔＪ．Ｋ．Ｗｕｓｐ．ｎｏｖ．ＳｐｅｃｉｅｓｎｏｖａａｆｉｎｉｓＡｌｓｏｐｈｉｌａｃｏｓｔｕｌａｒｉｓＢａｋ．ｅｔＡｌ...     

荷兰菊组织培养快繁技术研究

本文利用组织培养技术研究荷兰菊的快速繁殖,为大量培育荷兰菊种苗提供可靠方法。通过多种培养基的试验筛选,找出较满意的培养方法、三种培养基依次使用,可以达到快速繁殖目的。三种培养基分别是：ＭＳ＋ＫＴＯ·ｌｍｇ／ｌ＋糖２０９／１＋琼脂７ｇ／ｌ、ＭＳ＋６—ＢＡ５ｍｇ／ｌ＋ＮＡＡＯ．０１ｍｇ／ｌ＋糖２０９／ｌ＋琼脂７ｇ／ｌ、１／ＺＭＳ＋ＮＡＡＯ．ｌｍｇ／ｌ＋糖２０ｇ／ｌ＋琼脂７ｇ／ｌ·三种培养基ｐＨ均为６。     

组胺H_1受体激动剂PEA抑制胃酸分泌效应的中枢机制

本文分析了中枢注射ＰＥＡ抑制胃酸分泌效应的脑内过程。雄性Ｗｉｓｔａｒ大鼠,摘除双侧肾上腺,用３７℃的生理盐水通过恒流泵进行连续胃液流。第三脑室给药,观察其对五肽促胃液素（１６０μｇ／ｋｇ,ｓ．ｃ．）诱导的胃酸分泌的影响。结果如下：（１）预先脑室注射抗ＣＲＦ血清（２．５μｌ,１：２００００）可阻断１ＯμｇＰＥＡ的中枢抑酸效应;（２）分别脑室给予ＣＲＦ（１．０和２．０μｇ）和β－内啡肽（０．９４和１．２５μｇ）均明显抑制胃酸分泌;（３）预先注射纳洛酮（５．０μｇ,ｉ,ｃ．ｖ,）可取消ＣＲＦ（１．０μｇ）的中枢抑酸效应,而预先注射抗ＣＲＦ血清（２．５μｌ）对β－内啡肽（０．９４μｇ）的中枢抑酸效应无明显影响。结果提示：ＰＥＡ可能首先引起ＣＲＦ释放,后者再刺激内源性阿片肽释放,从而导致迷走介导的胃酸分泌抑制效应。     

pH值、激素对新疆紫草悬浮培养细胞生长及紫草宁衍生物合成的影响

报道了不同ｐＨ值、激素对新疆紫草悬浮培养细胞生长及紫草宁衍生物合成的影响。结果表明,新疆紫草细胞具有自我调节其培养液ｐＨ值的功能。适合于细胞生长及紫草宁衍生物形成的ｐＨ值为５．６±０．４０。ＢＡＰ、２,４－Ｄ、ＮＡＡ或ＩＢＡ对细胞生长无显著的促进作用,且都会抑制紫草宁衍生物的形成。在生长培养基中添加１．０ｍｇ／ｌ　ＩＡＡ和０．５ｍｇ／ｌＫＴ可促进细胞生长,而在生产培养基中附加０．１ｍｇ／ｌＫＴ和０．７５─１．０ｍｇ／ｌＩＡＡ则有利于紫草宁衍生物含量及产量的提高。     

Genetic toxicology: can we design predictive in vivo assays?

The present analysis examines the assumptions in, the perceptions and predictivity of and the need for short-term tests (STTs) for genotoxicity in light of recent findings that most noncarcinogens from the National Toxicology Program are genotoxic (i.e., positive in one or more in vitro STTs). Reasonable assumptions about the prevalence for carcinogens (1-10% of all chemicals), the sensitivity of these STTs (ca. 90% of all carcinogens are genotoxic) and their estimated "false positive" incidence (60-75%) imply that the majority of chemicals elicit genotoxic responses and, consequently, that most in vitro genotoxins are likely to be noncarcinogenic. Thus, either the usual treatment conditions used in these in vitro STTS are producing a large proportion of artifactual and meaningless positive results or else in vitro mutagenicity is too common a property of chemicals to serve as a useful predictor of carcinogenicity or other human risk. In contrast, the limited data base on in vivo STTs suggests that the current versions of these assays may have low sensitivity which appears unlikely to improve without dropping either their 'short-term' aspect or the rodent carcinogenicity benchmark. It is suggested that in vivo genotoxicity protocols be modified to take into consideration both the fundamentals of toxicology as well as the lessons learned from in vitro genetic toxicology. In the meantime, while in vivo assays are undergoing rigorous validation, genetic toxicology, as currently practiced, should not be a formal aspect of chemical or drug development on the grounds that it is incapable of providing realistic and reliable information on human risk. It is urged that data generated in new, unvalidated in vivo genotoxicity assays be exempted from the normal regulatory reporting requirements in order to encourage industry to participate in the laborious and expensive development of this next phase of genetic toxicology.     

From quantal counts to mechanisms and systems: the past, present, and future of biometrics in environmental toxicology

As appreciation for human impact on the environment has developed, so have the experimental systems and associated statistical tools that quantify this impact. Toxicological study in particular has grown in its complexity and its need for advanced statistical support. Within this perspective, we describe statistical practice in environmental toxicology and risk assessment. We present two case studies, one from mammalian toxicology and one from aquatic toxicology, that highlight the evolution of statistical practice in environmental toxicology.     

铝的生态与健康风险研究进展

人为原因加快了铝进入环境的速度,也加剧了铝对生命组分的毒害作用与危害。本文从毒理生态学、分子生态学等不同角度分析了铝对环境的生态风险和对人类的健康风险,概述了有关铝生态风险与健康风险两个方面的最新研究进展,对控制、消除环境中铝毒的发生提出了展望。     

Endocrine disruptors: Revisiting concepts and dogma in toxicology

During the last decades, a large number of observations have shown that some exogenous substances could interfere with hormone levels or hormone action and could induce toxic effects. This has led to the identification of endocrine disruptors more than 25 years ago as a new class of toxic agents (Zoeller et al., 2014). Those widely used agents correspond to a variety of chemical classes, are not identified by their chemical structure or by a specific type of usage, but rather by their mechanisms of action; this is not unprecedented in toxicology since genotoxicants have also been identified by their mechanism of action, i.e. their ability to alter DNA structure and function.     

Mapping Drug Physico-Chemical Features to Pathway Activity Reveals Molecular Networks Linked to Toxicity Outcome

The identification of predictive biomarkers is at the core of modern toxicology. So far, a number of approaches have been proposed. These rely on statistical inference of toxicity response from either compound features (i.e., QSAR), in vitro cell based assays or molecular profiling of target tissues (i.e., expression profiling). Although these approaches have already shown the potential of predictive toxicology, we still do not have a systematic approach to model the interaction between chemical features, molecular networks and toxicity outcome. Here, we describe a computational strategy designed to address this important need. Its application to a model of renal tubular degeneration has revealed a link between physico-chemical features and signalling components controlling cell communication pathways, which in turn are differentially modulated in response to toxic chemicals. Overall, our findings are consistent with the existence of a general toxicity mechanism operating in synergy with more specific single-target based mode of actions (MOAs) and provide a general framework for the development of an integrative approach to predictive toxicology.     

An analysis of the Gene-Tox Carcinogen Data Base

The Gene-Tox Carcinogen Data Base is an evaluated source of cancer data on 506 chemicals selected in part for their previous assessment in genetic toxicology bioassays. This data base has been analyzed for the distribution of these chemicals into chemical classes. The major chemical classes (6% or greater of the total data base) are: acyl-, alkyl-, and aryl-halides; alcohols and phenols; aliphatic and aromatic amines, amides, and sulfonamides; benzene-ring-containing chemicals; organo-lead, -mercury, -phosphorous compounds, metals and derivatives, phosphoric acid esters, and phosphoramides; and polycyclic aromatic hydrocarbons. Cancer studies representing a subset of the Gene-Tox Carcinogen Data Base, 199 chemicals which were rated as Sufficient Positive/Negative or Limited Positive/Negative, were examined for distribution of those studies by animal species, gender, route of chemical administration, duration of study, major tumor sites, and major tumor types. These analyses revealed that the Gene-Tox Carcinogen Data Base contains a large number of lifetime studies involving the rat and mouse treated by oral routes of administration. The major organs that were targets were: liver, lung, skin, forestomach, bladder, and mammary gland, while the major tumor types were: carcinoma, sarcoma, papilloma, and adenoma. Chemicals in the data base have been assessed for species-specific carcinogenic effects, and these results indicate that for mice and rats there is a high correspondence (85%). This number is higher than that (71%) reported by Tennant et al. (1986) based on the recent results of 72 chronic cancer bioassays performed by the National Toxicology Program. This difference is probably based on the nature of the chemicals selected for inclusion in both data bases. Although the absolute value of this correspondence is unknown, it would seem to be within this range. When chemicals in the Gene-Tox Carcinogen Data Base were examined for their previous evaluation in 73 genetic toxicology bioassays, only 26 of these bioassays had 30 or more chemicals. In these 26 bioassays, the prevalence of positive chemicals was generally greater than 80-90%. This suggests that a thorough evaluation of genetic toxicology bioassays in regard to their ability to predict carcinogenic effects in animals is premature at this time.     

New achievements in human cell toxicology: the 20th annual workshop on in vitro toxicology

The 20th Annual Workshop on In Vitro Toxicology (Oxford, UK, September 22-24, 2002) was convened as part of a European meeting entitled Human Cell Culture 2002. The meeting was arranged by the Scandinavian Society for Cell Toxicology (SSCT), the European Tissue Culture Society and the British Prostate Group. Two sessions, which are summarised in this report, were devoted to in vitro toxicology: Human Cell Toxicology and The SSCT Free Paper Session. Outstanding experts in the field of toxicology outlined contemporary approaches in toxicity testing in their lectures. Short oral presentations demonstrated a variety of in vitro model systems and methodologies, which can be useful for investigating human toxicity, as well as for studies on mechanisms of toxicity.