Airborne emissions at skin surfaces: a potential biological exposure index

 Dermal exposures of methanol were administered in a clinical study designed to compare several biological indicators. Four subjects were exposed in five exposure sessions of varying length. In each session, a sequence of measurements of methanol concentrations in blood, breath, and headspace samples of air at exposed and unexposed skin were collected before and after dermal exposures. Skin headspace samples, collected in gas sampling bags, were designed to reflect equilibrium skin: air partitioning. At exposed skin, headspace samples were highly elevated for at least 8 h following exposure, indicating the presence of a methanol reservoir in skin. After exposure, methanol concentrations at exposed skin showed a rapid initial decline, then a slower first-order decrease. Methanol concentrations were clearly detectable in headspace samples at unexposed skin. Substantial transfer from exposed skin occurred due to mechanical contact and washing. When transfer was restricted, surface concentrations at unexposed skin were similar to levels in breath and were strongly correlated to methanol concentrations in blood. While results are preliminary due to the small sample sizes and several unresolved experimental issues, the simple, rapid, and noninvasive skin headspace measurements appear useful as a biological exposure indicator that clearly shows the presence and site of a dermal exposure, and measurements at unexposed skin reflect concentrations in blood. Received: 14 March 1995/Accepted: 3 November 1995     

山刺玫果实的化学成分及营养成分

山刺玫果实的化学成分及营养成分李京民，王静萍，范明娟，祝凤池，张长城（中国科学院植物研究所，北京１０００４４）ＣｈｅｍｉｃａｌａｎｄＮｕｔｒｉｔｉｏｎａｌＣｏｎｓｔｉｔｕｅｎｔｓｏｆＦｒｕｉｔａｎｄＣｏｎｃｅｎｔｒａｔｅｄＦｒｕｉｔＪｕｉｃｅｏｆＲｏ...     

珠子参挥发油的化学成份

利用气相色谱—质谱—计算机联用仪分析了云南省腾冲县产珠子参挥发油的成份,从中鉴定了27种化合物,测定了它们的相对含量,其中有10种倍半萜烯和一种倍半萜醇。     

香茶菜属植物的化学成分与药理作用研究进展

我们主要综述了国内近年来有关香茶菜属植物在化学成分、药理作用、临床应用方面的研究进 展,并且讨论了这一领域的研究方向。     

458例尿路结石成分分析

目的 探讨西安地区尿路结石的成分状况，为临床防治提供帮助。方法对458例尿路结石标本进行化学成分测定，并结合临床资料进行比较。结果尿路结石男性发病多于女性，男、女比为2．1：1，20一50岁为高发年龄，上尿路结石明显多于下尿路结石，上、下尿路结石之比为10．5：1。结石成分以混合结石占多数，为325例（71％），其中以草酸钙，磷酸钙与尿酸的混合结石为主。对比混合性结石及单纯性结石发现，各种成分所占比例基本一致。结论结石成分分析对于了解结石成因、预防结石形成和复发具有重要的意义。     

Propolis allergy

87% of the propolis product "LB-1", originally reported to be 1,1-dimethyl-allyl caffeic acid ester, was shown by GC/MS analysis to consist of 3 isomeric pentenyl caffeates, 63% of which are 1,1-dimethylallyl caffeate. These pentenyl caffeates proved to be the major sensitizers of propolis and of poplar bud secretion in our previous study. In addition, 3 further minor allergens have now been investigated. Experimental sensitization indicates that phenylethyl caffeate is as strong a sensitizer as the major allergen "LB-1", while benzyl salicylate is a moderate sensitizer. Benzyl cinnamate plays only a subordinate role. At least 3 further esters of caffeic acid or cinnamic acid remain to be studied. Interestingly, relationships between propolis and balsam of Peru were found. 8 compounds are common to both materials. Thus "cross-reactions" or concomitant reactions in propolis-sensitive individuals to balsam of Peru are explainable.     

The sodium channels of the neuroblastoma x glioma 108 CC 15 hybrid cell change their sensitivity for volatile and local anesthetics upon continuous passage

Summary We have studied the ion flux through the sodium channels of low passage number (<50p.) and high passage number (>150p.) neuroblastoma x glioma hybrid cells using [¹⁴C] guanidinium and specific neurotoxins to induce channel opening and closing. The sodium channels of low passage number hybrid cells could be opened by veratridine alone, suggesting the presence of voltage dependent channels in agreement with electrophysiological studies reported in the literature. The sodium channels of the high passage number hybrid cells, however, needed the synergistic action of veratridine and scorpion toxin for activation suggesting that these channels are silent. The [¹⁴C] guanidinium ion flux through the sodium channels of the high passage number hybrid cells was inhibited by significantly lower concentrations of the volatile anesthetics (halothane, isoflurane and enflurane) and the lcoal anesthetics (tetracaine and bupivacaine) than the comparable flux through the sodium channels of the low passage number hybrid cells.Dedicated to Prof. Dr. E. Wecker on the occasion of his 65th birthday.     

胡萝卜籽挥发油的抗生育作用

胡萝卜籽挥发油对小鼠有抗着床,抗早、中和晚期妊娠作用。对大鼠也有抗着床作用。挥发油中的萜类碳氢化合物部位,对小鼠皮下注射抗早期妊娠的ED_(50)为2.9ml/kg,甲地孕酮和hCG能明显逆转其作用;对假孕小鼠蜕膜瘤有抑制作用,此作用不能被甲地孕酮拮抗,皮下注射于早孕大鼠24、48小时后血浆孕酮浓度明显下降。以上提示其抗早孕作用机制可能与抑制孕酮合成和蜕膜反应有关。此外,挥发油碳氢部分无雌激素和抗雌激素活性,低浓度时对早孕大鼠离体子宫的收缩活动没有影响,高浓度则表现抑制作用。     

白桦叶的二苯基庚烷类化合物

目的：对白桦叶的化学成分做系统研究,以更好的开发利用我国的植物资源。方法采用硅胶柱、凝胶柱及制备薄层色谱法进行了分离,通过波谱技术（^ＨＮＭＲ,^１３ＣＮＭＲ,^１Ｈ－^１ＨＣＯＳＹ,ＨＭＱＣ,ＨＭＢＣ,ＮＯＥＳＹ）进行结构鉴定。结果：分离鉴定了４种二苯基庚烷类化合物,槭木素丁（１）,氧杂二苯庚烯（Ⅱ）,１７－甲基－１５－甲氧基－７－７氧代槭木素丁 (Ⅲ）,槭木素十一（Ⅳ）,结论：化合物Ⅲ,Ⅳ均首次从本种植物中分离得以,并纠正了化合物Ⅲ的碳谱数据归属。     

鱼腥草的研究进展

综述了鱼腥草在分布,栽培,化学成分,药理作用,临床应用及产品开发等方面的研究进展,并对鱼腥草今后研究和方向进行了展望。