铁路危险品货运站空气污染指标的探讨

铁路危险品货运站（危货站）空气污染物种类多,空气污染严重,为探讨对其监测和评价的综合性能指标和方法,采用空气耗氧量（ＡＯＤ）和ＳＯＳ致遗传毒性原位监测法（ＳＯＳ原位法）,分别对危货站空气污染进行了研究。结果表明,危货站中各点所测ＡＯＤ值与对照区ＡＯＤ值,在统计学上差异均有显著性（Ｐ〈０．０５）。ＳＯＳ原位法显示,随采样体积的增加,β－半乳糖苷酶的量也增加,采样体积与酶诱导率之间存在剂量－反应关系。     

Mechanisms of perceptual learning

Systematic measurements of perceptual learning were performed in the presence of external or stimulus noise. In the new external noise method (Dosher, B, & Lu, Z.-L. (1997). Investigative Ophthalmology and Visual Science, 38, S687; Lu, Z.-L., & Dosher, B. (1998). Vision Research, 38, 1183-1198), increasing amounts of external noise (white Gaussian random noise) is added to the visual stimulus in order to identify mechanisms of perceptual learning. Performance improved (threshold contrast was reduced) over days of practice on a peripheral orientation discrimination task--labelling Gabor patches as tilted slightly to the right or left. Practice improvements were largely specific to the trained quadrant of the display. Performance improved at all levels of external noise. The external noise method and perceptual template model (PTM) of the observer identifies the mechanism(s) of performance improvements as due to stimulus enhancement, external noise exclusion, or internal noise suppression. The external noise method was further extended by measuring thresholds at two threshold performance levels, allowing identification of mixtures in the PTM model. Perceptual learning over 8-10 days improved the filtering or exclusion of external noise by a factor of two or more, and improved suppression of additive internal noise--equivalent to stimulus enhancement--by 50% or more. Coupled improvements in external noise exclusion and stimulus enhancement in the PTM model may reflect channel weighting. Perceptual learning may not reflect neural plasticity at the level of basic visual channels, nor cognitive adjustments of strategy, but rather plasticity at an intermediate level of weighting inputs to decision.     

3 124例各类斜视手术的分布调查

目的：了解临床各类斜视手术的分布情况,以掌握最常见斜视手术分布数据。方法：３年３１２４例斜视手术资料的统计分析。结果：共同性斜视的手术２６２９例占８４．２％。麻痹性斜视的手术４９５例占１５．８％。共同性外科视的手术１７７９例占６７．７％。先天性麻痹性斜视手术中先天性上斜肌麻痹手术量占第一位。后天性麻痹性斜视手术中外直肌麻痹手术量占第一位。结论：最常见的斜视手术是共同性斜视。共同性外斜视的手术量最大     

新型弹性襻前房型人工晶体植入术临床分析

为探讨新型弹性襻前房型人工晶体植入的效果,观察了２３例２４只眼。其中老年性白内障１８眼,外伤性白内障６眼。其中包括１３眼行二期植入术。病例随访时间２个月至２年。结果：２４只眼中,１７眼（７０．８３％）视力恢复至４．５或４．５以上,５眼（２０．８３％）恢复至５．０或５．０以上。结论：新型弹性襻前房型人工晶体植入术操作简单,安全、有效     

Roles of oxygen radicals and elastase in citric acid-induced airway constriction of guinea-pigs

Antioxidants attenuate noncholinergic airway constriction. To further investigate the relationship between tachykinin-mediated airway constriction and oxygen radicals, we explored citric acid-induced bronchial constriction in 48 young Hartley strain guinea-pigs, divided into six groups: control; citric acid; hexa(sulphobutyl)fullerenes + citric acid; hexa(sulphobutyl)fullerenes + phosphoramidon + citric acid; dimethylthiourea (DMTU) + citric acid; and DMTU + phosphoramidon + citric acid. Hexa(sulphobutyl)fullerenes and DMTU are scavengers of oxygen radicals while phosphoramidon is an inhibitor of the major degradation enzyme for tachykinins. Animals were anaesthetized, paralyzed, and artificially ventilated. Each animal was given 50 breaths of 4 ml saline or citric acid aerosol. We measured dynamic respiratory compliance (Crs), forced expiratory volume in 0.1 (FEV0.1), and maximal expiratory flow at 30% total lung capacity (Vmax30) to evaluate the degree of airway constriction. Citric acid, but not saline, aerosol inhalation caused marked decreases in Crs, FEV0.1 and Vmax30, indicating marked airway constriction. This constriction was significantly attenuated by either hexa(sulphobutyl)fullerenes or by DMTU. In addition, phosphoramidon significantly reversed the attenuating action of hexa(sulphobutyl)fullerenes, but not that of DMTU. Citric acid aerosol inhalation caused increases in both lucigenin- and t-butyl hydroperoxide-initiated chemiluminescence counts, indicating citric acid-induced increase in oxygen radicals and decrease in antioxidants in bronchoalveolar lavage fluid. These alterations were significantly suppressed by either hexa(sulphobutyl)fullerenes or DMTU. An elastase inhibitor eglin-c also significantly attenuated citric acid-induced airway constriction, indicating the contributing role of elastase in this type of constriction. We conclude that both oxygen radicals and elastase play an important role in tachykinin-mediated, citric acid-induced airway constriction.     

The effect of pregnenolone 16alpha-carbonitrile on the pharmacokinetics and metabolism of dapsone in rats.

The purpose of this study was to evaluate the effect of pregnenolone 16 alpha-carbonitrile (PCN) on the interconversion pharmacokinetics and metabolism of dapsone. To determine microsomal CYP3A activity and protein, eight rats (4 PCN, 4 corn oil) received a 1 mg kg(-1) intravenous bolus dose of dapsone, followed by blood and urine sampling. The formation clearance of dapsone hydroxylamine (CLf DDS-NOH) was calculated from the obtained samples. Interconversion pharmacokinetics estimates were obtained after 10 rats (5 PCN, 5 control) received 1 mg kg(-1) dapsone or 1.17 mg kg(-1) monoacetyldapsone, with a 24-h wash-out. Results from the interconversion analysis demonstrated that PCN significantly increased systemic clearance (CLs) of dapsone, but not its interconversion. The in-vivo/in-vitro correlation study demonstrated that PCN significantly increased CLs of dapsone (8.55 to 16.39mLmin(-1); P<0.01) and CLf DDS-NOH (0.13 to 0.18mLmin(-1); P<0.01). PCN treatment produced a 69% increase in CYP3A protein, and increased 6beta- and 2beta-hydroxytestosterone formation rates. Significant correlations were found between CLf DDS-NOH and either 6beta- (r2 = 0.925), 2beta-hydroxytestosterone (r2 = 0.92), or CYP3A1/2 protein (r2= 0.60). We conclude that PCN treatment produces significant increases in CLs (dapsone) and CLf (DDS-NOH) in rats. These changes were not due to changes in the reversible metabolism of dapsone. These results suggest that the formation clearance of dapsone hydroxylamine reflects alterations in CYP3A activity, despite the fact that it accounted for a small part of the systemic clearance of dapsone.     

中国汉族人不同年龄和性别载脂蛋白E等位基因频率的群体分布

目的 研究在上海地区健康汉族人中不同年龄和性别的载脂蛋白Ｅ基因频率的群体分布,方法 本次调查包括６４９名健康汉族人（女：２３７人,男：４１２人）载脂蛋白Ｅ基因组ＰＣＲ扩增,前引物：５′－ＧＧＣ,ＡＣＧＧＣＴＧＴＣＧＡＡＧＧＡＧＣＴ－３′;后引物：５′－ＧＡＴ ＧＧＧ ＧＣＴ ＧＡＧ ＧＣＣ ＧＣＧ ＣＴ－３′,ＰＣＲ产物用５单位限制性内切酶Ｃｆ０Ｉ酶切,用２０％聚丙烯酰胺凝胶电泳分离。结果：Ａｐｏ     

影响重症急性胰腺炎预后的主要因素

目的 :探索重症急性胰腺炎分度和治疗方案对预后的影响。方法 :回顾性分析 1983年— 1998年间176例重症急性胰腺炎患者临床资料 ,根据胰腺出血坏死程度、腹水量及胰外受侵范围 ,将重症急性胰腺炎分为 4度 ,分析各度治愈率和采用不同方案的治疗效果。结果 : 度治愈率为 10 0 % , 度 69.3 % , 度 5 3 .1% , 度2 7.3 %。除 度、 度间差异不明显 ( P>0 .0 5 )外 ,其余各度之间均有明显差异 ( P<0 .0 5 )。 度中切除术组疗效明显差 ( P<0 .0 5 )。结论 :影响预后的主要因素 :1胰腺坏死程度 ,坏死越重 ,预后越差。 2治疗方法的选择 ,治愈率以切除组最差 ( 2 8.6% ) ,清除术组 68.4 % ,非手术组 82 .4 % ,因而 ,保守治疗列为首选治疗方案     

RP—HPLC测定清眩丸中欧前胡素的含量

目的：建立反相高效液相色谱测定清眩丸中欧前胡素含量的方法。方法：采用乙醇做溶剂,水浴加热回流提取。ＬＵＮＡ－Ｃ１８色谱柱分离测定,流动相为乙腈－水（５３∶４７）,流速１ｍＬ·ｍｉｎ－１,检测波长３００ｎｍ。结果：欧前胡素与其相邻峰的分离度是１５,理论板数按欧前胡素峰计算是１６１５５,欧前胡素对照品线性范围是１４６２～４８７５μｇ·ｍＬ－１,加样平均回收率９８０％。结论：用本文方法测定清眩丸中欧前胡素的含量,操作简便,结果准确。