北京市0～6岁儿童血铅水平与相关影响因素的研究

目的　了解近期北京市 0～ 6岁儿童血铅水平及其影响因素。方法　采取分层整群随机抽样的方法。 2 0 0 1年 5～ 7月调查北京市常住人口中 0～ 6岁儿童 2 2 62名。采用石墨炉原子吸收法进行微量血中铅含量的测定 ,并做相关因素问卷调查。结果　北京市 0～ 6岁儿童血铅水平均值为96.8μg L,血铅值≥ 10 0 μg L为 3 5.7% ,血铅值≥ 2 0 0 μg L为 2 .5%。农村儿童铅中毒为 43 % ,明显高于城区和郊区儿童。 2岁组铅中毒为 45.1%高于其他年龄组。男童血铅平均值 10 0 .2 μg L明显高于女童血铅平均值 93 .0 μg L(P <0 .0 1)。不喝或偶喝牛奶、居室距繁华马路≤ 50m、家庭居住 1层楼房或平房为儿童高血铅的主要危险因素。结论　目前北京市儿童血铅水平≥ 10 0 μg L的比例不容忽视 ,应对重点人群采取行之有效的干预措施     

重度失水所致应激性高血糖症

本文报道2例肠梗阻和1例有机磷农药中毒患者出现暂时性高血糖症。该3例患者均无糖尿病史,因有重度失水,经大量补液纠正失水后血糖迅速恢复正常。口服葡萄糖耐量试验正常。作者认为非糖尿病患者可因重度失水而致应激性高血糖症。     

Preventing percutaneous absorption of industrial chemicals: the "skin" denotation

Percutaneous absorption has received comparatively little attention in occupational health, although this route of entry has repeatedly caused occupation-related intoxications. In practice, the evaluation of skin penetration rates is far from simple. Much evidence has been obtained from studies of chemicals used for cosmetics and topical therapeutics, but the information available on compounds encountered in occupational health is limited. The data obtained from experimental studies have confirmed that the concentration, type of vehicle, skin area, skin condition, and extent of occlusion are important factors in determining the degree of percutaneous absorption, but no general model has been developed. Also, too little is known about the basic chemical properties governing the rate of penetration. Thus, prediction is difficult and bound to be rather inaccurate. Current preventive practice follows the procedure used by ACGIH and is mainly based on a "skin" denotation in official listings of chemicals to which exposure limits have been allocated. The number of substances and groups of chemicals which have received skin denotation in 17 selected countries varies between 24 and 179 and a total of 275 are listed as a skin hazard in one or more countries; ACGIH lists 143. Thus, the denotation practice varies. As an unfortunate result of these discrepancies and the dichotomy of skin denotation, the absence of skin denotation may erroneously indicate that efforts to protect the skin are unnecessary. Thus, an evaluation of skin penetration potentials should be incorporated in occupational health practice as a supplement to the official denotations.     

The role of central parts of the brain in the control of sound production during courtship in Drosophila melanogaster

The question of the roles of the two main parts of the insect brain, the mushroom bodies and the central complex, in controlling motor coordination and triggering a variety of behavioral programs, including sound production, remains controversial. With the aim of improving our understanding of this question, we studied the parameters of songs used by five-day-old males during courtship for fertilized wild-type females (Canton-S, C-S) over 5-min periods at 25°C; males were of two wild-type Drosophila Melanogaster lines (Berlin and C-S). Berlin males lacking mushroom bodies because of treatment with hydroxyurea during development (chemical removal of the mushroom bodies) were used, along with two mutants with defects in the mushroom bodies (mbm ¹ and mud ¹), two mutants with defects in the central complex (ccb ^KS127 and cex ^KS181), and mutant cxb ^N71 with defects in both the mushroom bodies and the central complex. The experiments reported here showed that courtship songs in males lacking mushroom bodies were virtually identical to those of wild-type males. The main parameters of pulsatile song in mutants mbm ¹ and mud ¹ (interpulse interval and train duration) were insignificantly different from those of the songs of wild-type flies, though the stability of the pulse oscillator was the same. Flies of these lines were no different from wild-type flies in terms of courtship success (percentage of copulating pairs in 10-min tests). Conversely, the songs of mutants with defects in the central complex differed from those of wild-type males. Firstly, there was degradation of the stability of the pulse oscillator and interpulse intervals were very variable. In addition, pulses were often significantly longer and appeared multicyclic, as in the well-known cacophony mutant, while the mean train duration was significantly shorter. Males of the line cex ^KS181 usually courted very intensely, though abnormal sounds were generally emitted. Mutants cex ^KS181 and ccb ^KS127 were significantly less successful in courtship than wild-type flies. These data show that the central complex appears to play a very important role in controlling song, while the mushroom bodies are not related to this function.     

血液灌流治疗百草枯中毒临床观察

目的观察血液灌流治疗百草枯中毒的疗效。方法血液灌流治疗组（治疗组）22例在常规治疗的基础上，采用血液灌流治疗并观察疗效。非血液灌流治疗组（对照组）16例。结果治疗组22例中死亡14例，病死率为63．6％，对照组病死率87．5％，两组相比P〈0．05。结论血液灌流治疗百草枯中毒可提高治愈率，降低病死率，是临床上抢救百草枯中毒较有效的方法。