青年人群血清流感抗体水平纵向监测

通过对北京４０５例青年１９９２～１９９４年流感抗体的纵向监测结果表明，３年中Ｂ型流感表现很活跃，抗体分别在１９９３年和１９９４年春出现高峰。Ａ型流感抗体在１９９３年春出现高峰。其中２１８例个体连续３年６次抗体检测，据抗体波动提示：３年中流感３个亚型总的感染频率为４４０％，每个体每年平均为１．４次，其中Ａ１型感染频率最高，每个体３年内平均１．８次；Ａ３型次之为１．５２；Ｂ型为１．０６。流感３个亚型抗体在机体内有６７％～７３％高水平抗体个体可在０．５～１年内下降至≤２０的低水平。２１８例个体中Ａ１型抗体３年内长期低水平者有３％，Ａ３有９％，Ｂ有３８％。     

溴氰菊酯对白纹伊蚊（Aedesalbopictus）C6／36细胞株的细胞遗传学效应

本研究选择１０μｇ／ｍｌ、２０μｇ／ｍｌ、４０μｇ／ｍｌ浓度的溴氰菊酯处理白纹伊蚊Ｃ６／３６细胞，以ＭＭＣ作为阳性对照物，观察溴氰菊酯处理２４ｈ后对Ｃ６／３６细胞染色体畸变率和姐妹染色单体互换（ＳＣＥ）频率的影响。结果显示，三个浓度的溴氰菊酯对Ｃ６／３６细胞染色体畸变率均没有显著影响（Ｐ＜０．０５）；溴氰菊酯浓度在４０μｇ／ｍｌ时可诱导Ｃ６／３６细胞ＳＣＥ频率轻度增高（Ｐ＞０．０５），而溴氰菊酯浓度在１０μｇ／ｍｌ、２０μｇ／ｍｌ时，对Ｃ６／３６细胞ＳＣＥ频率没有诱导作用。表明溴氰菊酯对Ｃ６／３６细胞的遗传学效应较弱     

Effect of anoxia on in vitro bladder function.

Previous studies have demonstrated that the ability of the in vitro whole bladder to empty in response to bethanechol administration was inhibited by anoxia while its ability to generate pressure decreased only slightly. One question was not addressed by these early studies: Is the anoxic effect selective for receptor-mediated contractile stimulation (as opposed to non-receptor-mediated contractile stimulation)? The present study was designed to compare the effect of anoxia on the ability of the in vitro bladder to generate pressure, sustain pressure, and empty in response to field stimulation (FS), bethanechol and KC1 administration. Each New Zealand white rabbit was anesthetized with pentobarbital and the bladder removed. The bladder was mounted as a whole-bladder preparation in a 300-ml isolated bath containing Tyrode's solution at 37 degrees C and equilibrated with 95% O2, 5% CO2. Anoxia was produced by changing the gas mixture to 95% nitrogen, 5% CO2. The effect of anoxia on the response to FS, bethanechol, and KCl was determined at different times after the initiation of anoxia. The results of these studies can be summarized as follows. (1) Anoxia induced a time-dependent decrease in the rate of pressure generation, the magnitude of pressure generation, and the percent volume emptied in response to FS and bethanechol. (2) At all time periods of anoxia, the ability of the bladder to empty was inhibited to a significantly greater degree than either the rate of magnitude of pressure generation (for both FS and bethanechol administration).(ABSTRACT TRUNCATED AT 250 WORDS)