不同强度噪声所致蜗内直流电位改变及其机制探讨

本实验观察105 dB—125 dB(声压级,SPL)白噪声暴露20min 对豚鼠耳蜗直流电位(EP)的影响.发现随着噪声强度的增加,EP 发生不同形式的改变:115 dB噪声使 P—EP 增大,而125 dB 则使其减小,但各组负 EP(N—EP)变化不大。提示有血管纹功能从代偿性增强到失代偿的变化过程。本文还利用几种钾离子通道阻断剂对EP 改变的通道机制作了探讨。     

船舶噪声对豚鼠耳蜗微音电位响应曲线的影响

在排除电场干扰伪迹后，耳蜗微音电位响应曲线可以作为反映近全耳蜗电生理功能的一项测试指标。能方便而迅速地完成测试，结果可靠。船舶噪声暴露后，显示耳蜗损伤频带主要在３．１５～８ｋＨｚ范围。这与人噪声性听力损失的特征非常类似。     

黄芪丹参复方成分对一氧化氮合成阻滞孕鼠模型血浆IL-1、IL-10变化的影响

目的探讨黄芪丹参复方成分提高胎盘血供的分子机制，为临床有效防治胎盘血供不足所致妊娠并发症提供思路。方法提取分离黄芪、丹参复方成分，运用NOS（一氧化氮合酶）阻滞剂L－精氨酸甲酯（L—NAME）建立一氧化氮合成阻滞大鼠模型，ELISA法检测妊娠18d大鼠血浆IL－1、IL－10水平。以及胎盘超微形态学变化，大鼠血压、尿蛋白变化，以及仔鼠重、肝重、脑重、胎盘重等。结果一氧化氮合成阻滞模型组IL－1含量明显高于空白组（P〈0．01），经黄芪丹参注射液治疗后，血浆IL－1水平比模型组降低（P〈0．05）；模型组IL－10含量较空白组低（P〈0．01），中药组血浆IL－10水平高于模型组（P〈0．05）；胎盘形态学、血压、尿蛋白以及仔重、仔肝重、脑重等均有显著差异（P〈0．05，P〈0．01）。结论黄芪丹参复方成分可能对妊娠早期母－胎界面免疫平衡具有调控作用，通过促进局部生理抑制性免疫反应增强和杀伤、排斥免疫反应减弱，从而有利于母胎循环构建，维持胎盘血液供应。     

再生障碍性贫血患者血清一氧化氮与细胞因子水平分析

生物体内的一氧化氮 (NO)作为一种反应极强的效应分子 ,不仅参与免疫调控 ,而且也是造血祖细胞生长和分化不可缺少的调节因子 [1 ]。本文通过对再生障碍性贫血 (AA)患者血清 NO与白细胞介素 - 2 (IL- 2 )、肿瘤坏死子 (TNF)、血小板生成素 (TPO)、红细胞生成素 (EPO)、GM- CSF、5种细胞因子水平测定 ,分析其与外周血象及各细胞因子间的相互关系 ,并探讨 NO及 IL- 2等细胞因子在 AA发生发展过程中的作用。1　材料和方法1.1　材料1.1.1　标本来源　 AA患者 5 0例 ,以 2 0 0 2年 3月至 2 0 0 4年4月我院确诊为 AA的患者为研究对象…     

噪声作业人员职业体验研究

采用华西医科大学劳动卫生教研室研制的系统化职业心理测验（ＯＰＴ）软件，对四川第一棉纺织厂织布车间噪声（１０１．２ｄＢ（Ａ））作业女工９８人职业体验进行考察。以ＯＰＴ常模女性工人组为对照（年龄、工龄、文化程度等与观察组同），按标准化ＯＰＴ方法实施测验和统计分析。结果提示噪声作业女工职业体验欠佳，职业满意度、工作生活质量均低于常模。     

几种化合物对石棉诱发肺泡巨噬细胞产生一氧化氮的抑制作用

为了寻求一种适宜的石棉表面改性剂，利用体外细胞培养技术，通过测定培养液中亚硝酸根（ＮＯ－２）含量，观察了茫崖产温石棉对豚鼠肺泡巨噬细胞（ＡＭ）产生一氧化氮（ＮＯ）的诱导作用以及混合稀土、亚硒酸钠、柠檬酸铝对石棉诱发ＡＭ产生ＮＯ的影响。结果显示，温石棉纤维可使培养液中ＮＯ－２浓度升高，并呈明显的剂量反应关系；混合稀土、亚硒酸钠、柠檬酸铝均可抑制石棉诱发ＡＭ产生ＮＯ，而且随上述化合物浓度的升高，抑制作用增强。提示用混合稀土和亚硒酸钠拮抗石棉的致病作用有实际应用的可能。     

内毒素休克大鼠核因子κB活化规律及其在生物蝶呤诱生中的作用

目的观察内毒素休克大鼠血浆及主要脏器核因子(NF)κB活化规律及其对生物蝶呤(BH4)和一氧化氮(NO)表达水平的影响,探讨内毒素休克时NF-κB信号通路对BH4诱生NO的分子调控机制及其与多器官功能损害的关系。方法将47只大鼠按表格随机法分为正常组(8只)、内毒素／脂多糖(LPS)组(24只,每观察时相点8只,均同时注射LPS制成休克模型)和拮抗组[15只,每观察时相点5只,均同时注射LPS并以吡咯烷二硫代氨基甲酸盐(PDTC)拮抗]。休克及拮抗组于注射LPS后2、6、12 h观察,并与正常组同法处死,无菌留取大鼠血标本及肝、肺、肾组织,测定组织中NF-κB活性和三磷酸鸟苷环水解酶Ⅰ(GTP-CHⅠ)和诱导型一氧化氮合酶(iNOS)mRNA表达水平、血浆和组织中的BH4含量及NO水平、肝脏和肾脏功能指标、肺组织髓过氧化物酶活性。结果与正常组(例如肺组织中NF-κB活性为26±6)比较,LPS组大鼠组织中NF-κB迅速活化(P<0．01),并于注射后2 h达峰值(肺组织中为291±44);LPS组各组织中GTP-CHⅠ和iNOS mRNA表达、BH4和NO水平也较正常组明显升高(P<0．05或0．01),至伤后12 h仍持续较高水平。此外,该组相应器官功能均受到不同程度的损害。应用PDTC的拮抗组大鼠各组织中NF-κB活性均较LPS组有所降低,GTP-CHⅠ、iNOS mRNA表达及BH4、NO水平显著受抑,肝、肺、肾功能明显改善。结论内毒素休克时机体内NF-κB通路高度活化,并对BH4／NO系统具有明显调节效应;可通过下调BH4介导的iNOS的过度活化抑制NF-κB信号途径,从而减轻组织炎性反应,对机体脏器功能起到保护作用。     

Role of nitric oxide in modulating neurotransmitter release from rat striatum

The effect of the nitric oxide synthase inhibitor N-nitro- -arginine methyl ester (L-NAME) on the basal and stimulation-evoked release of dopamine (DA) and acetylcholine (ACh) was investigated in rat striatum. The experiments were carried out in isolated superfused striatal slices, loaded with either [³H]-dopamine or [³H]-choline.We have found that L-NAME reduced the elecrical field stimulation-evoked release of DA, while its enantiomer N-nitro-D-arginine methyl ester (D-NAME) was ineffective. In the presence of the nitric oxide (NO) precursor -arginine L-NAME failed to influence DA release. Furthermore, treatment with the N-methyl- -aspartate (NMDA) receptor antagonist MK-801 completely reversed the effect of L-NAME on striatal DA release. In contrast, L-NAME had no effect on either the basal or the stimulation-evoked ACh release in any experimental conditions studied.Our data indicate that endogenously produced NO is involved in the modulation of striatal DA, but not in ACh release. Furthermore, it seems likely that the modulatory effect of NO is linked to activation of presynaptic NMDA receptors located on the striatal dopaminergic nerve terminals.     

Road traffic noise around schools: a risk for pupil's performance?

Summary Noise levels around educational centres can negatively affect the performance of both teachers and pupils. Two public schools in Valencia, Spain, were selected for study. One of these schools was exposed to excessively high road traffic noise levels while the other was located in a relatively quiet area. The socioeconomic level of those attending the schools was very similar. A set of external and internal noise measurements were carried out, along with two different attention tests among the children. Test results were consistently better (both for tests and for children from different classrooms in each school) in the quiet school. Exposure to high traffic noise levels in the noisy school over the whole school year is a plausible determinant of these results.     

Abdominal vagotomy attenuates interleukin-1β-induced nitric oxide release in the paraventricular nucleus region in conscious rats

Nitric oxide (NO) has recently been shown to modulate the hypothalamic–pituitary–adrenal axis response to interleukin-1β (IL-1β). We measured levels of nitrite (NO₂⁻) and nitrate (NO₃⁻) in the hypothalamic paraventricular nucleus (PVN) region using an in vivo brain microdialysis technique in conscious rats. Intraperitoneally administered IL-1β produced a significant increase in both NO₂⁻ and NO₃⁻ levels in the PVN region. We also examined the possible involvement of the abdominal vagal afferent nerves in this effect. In abdominal-vagotomized rats, the increase was significantly attenuated compared to that in sham-operated rats. Our results suggest that the abdominal vagal afferent nerves are involved in intraperitoneally administered IL-1β-induced NO release in the PVN region.