Right ventricular abnormalities in sickle cell anemia: evidence of a progressive increase in pulmonary vascular resistance

OBJECTIVE: To assess the effects of sickle cell anemia (SCA) on the right ventricle (RV). STUDY DESIGN: Echocardiograms of 32 children with SCA were compared with age-matched healthy controls. RV measurements included diastolic area index, fractional area change, free-wall mass index, ejection time corrected for heart rate (ET(c)), and tricuspid regurgitation (TR) gradient. RESULTS: SCA subjects had elevated RV ETc (mean +/- standard deviation, 0.369 +/- 0.030 sec vs 0.351 +/- 0.022 sec; P < .01), diastolic area index (19.9 +/- 2.4 cm(2)/m(2) vs 13.2 +/- 2.1 cm(2)/m(2); P < .01) and free-wall mass index (33.2 +/- 4.4 g/m(2) vs 23.9 +/- 4.3 g/m(2); P < .01), whereas RV fractional area change (37 +/- 8% vs 36 +/- 4%) was not different from controls. Although RV diastolic area index in SCA paralleled the normal range over time, RV free-wall mass index continued to gradually rise throughout childhood (r = .42; P < .05). TR gradients > 2.5 m/sec, consistent with pulmonary hypertension, were found in 5 (16%) of SCA subjects, all older than 9 years. CONCLUSIONS: RV preload and systolic function do not worsen during childhood in SCA; however, RV mass index and the prevalence of pulmonary hypertension increase consistent with rising pulmonary vascular resistance.     

空气负离子对豚鼠噪声性听力损失的保护作用

目的：探索预防性吸入空气负离子对噪声性听力损失的保护作用和听力恢复规律。方法：选用听力正常豚鼠６３只耳，随机分为三个组，分别预先吸入空气负离子（浓度为０．９６ｘ１０６～１．０７ｘ１０６／ｃｍ３２ｈ／ｄｘ１１～１３）然后给与三种不同白噪声暴露（１１５ｄＢＳＰＬ０．５ｈ，１１５ｄＢＳＰＬ１ｈ及１１８ｄＢＳＰＬ１ｈ），并动态测定噪声暴露后８、２４、４８、７２、９６小时与８、２１、３１、４５天豚鼠的皮层听阈。结果：预防性吸入空气负离子具有减轻噪声件听力损失、促进听力恢复的作用；尤其对强噪声暴露（１１８ｄＢＳＰＬ１ｈ）所产生的听力损伤，吸与不吸空气负离子两组之间有非常显著的差异（Ｐ＜０．０１），吸空气负离子组豚鼠的听力大部分为暂时性阈移（ＴＴＳ），而不吸空气负离子的对照组则留有１８．２ｄＢ不可恢复的永久性阈移（ＰＴＳ）。结论：预先吸入空气负离子对噪声性听力损失有明显的保护效果，实验结果为进一步研究其保护作用及机理提供了理论依据和新途径。     

Air pollution and mortality in Central and Eastern Europe: An estimate of the impact

Air pollution is severe in some areas of Central and EasternEurope but the quality and representativeness of measurementsare not consistent. Studies in the Czech Republic and Polandhave shown an impact of air pollution on overall mortality,post-neonatal mortality and lung cancer. Estimates in this papersuggest that air pollution may cause up to 3% of all-cause,all-age mortality in the Czech Republic, which is some 9% ofthe mortality gap between this country and Western Europe. Theimpact in other countries of Central and Eastern Europe is probablysmaller.     

Retention of styrene following controlled exposure to constant and fluctuating air concentrations

An experiment was designed to determine whether the respiratory retention of sytrene vapor, as estimated from measurements of end-exhaled air, was the same during periods of both constant and fluctuating exposure. Six human subjects were exposed to styrene inside an experimental chamber. A computer-controlled system was used to generate time-varying air concentrations of styrene over 4–5 h in both multistep sequences of constant exposure (four subjects exposed to 15–99 ppm. of styrene in 100-min steps) and fluctuating patterns representative of occupational exposures (two subjects exposed to mean concentrations of styrene of 50 ppm). In the latter case, lognormally distributed exposures, which fit one of two first-order autoregressive models, were generated at intervals of 2.5 min. It was found that the concentration of styrene in end-exhaled air was reduced by about half if the subject inhaled one to three breaths of clean air prior to sampling. This suggests that significant amounts of styrene were desorbed from the lining of the lungs during the initial exhalation. The retention of styrene vapor during constant exposures was 0.935 and was independent of the level. During each of the two sets of fluctuating exposure the retention of sytrene was also constant and was independent of both the variance and the autocorrelation coefficient. However, the retention of styrene during fluctuating exposure (estimates ranged from 0.957 to 0.973) was significantly higher than that observed during the constant exposures. It is speculated that the difference in retention between the constant and the fluctuating exposure regimens is related to non-steady-state behavior of styrene in the richly perfused tissues, as suggested by Opdam and Smolders (1986) regarding tetrachloroethylene exposure.     

ATP生物荧光检测在气管镜清洗消毒质量监测中的应用研究

目的探讨三磷酸腺苷(ATP)生物荧光检测对气管镜清洗消毒合格参考值范围和检测方法。方法选取360条患者使用后的气管镜随机分为A、B、C三组,每组120条。A组床旁预处理后分为A1、A2两组(每组60条气管镜),B组气管镜在人工清洗后分为B1、B2两组,C组气管镜在高水平消毒后分为C1、C2两组,A1、B1、C1组采用细菌采样,A2、B2、C2组进行ATP生物荧光采样。两种采样方法对气管镜表面采样为全部长度涂抹采样,管腔的采样方法均为冲刷法。同时选取临床使用后的60条气管镜经过人工清洗后,对管腔运用冲洗法,对冲洗液进行ATP生物荧光检测,比较冲洗法和冲刷法对管腔采样的有效性。结果气管镜在人工清洗后,对管腔采样的冲洗法和冲刷法,两组ATP总量的相对发光值(RLU)差异有统计学意义(P=0.040)。气管镜在A1、B1组的细菌采样中,管腔和表面菌落数差异均有统计学意义(P均<0.001),高水平消毒后表面和管腔菌落数均为0;气管镜在A2、B2、C2三组的ATP生物荧光检测采样中,表面ATP总量RLU值A2与B2组间比较差异有统计学意义(P<0.001),B2与C2组间比较差异有统计学意义(P=0.040);管腔ATP总量RLU值A2与B2组间比较差异有统计学意义(P<0.001),B2、C2两组差异无统计学意义(P=0.450)。结论 ATP生物荧光采样冲刷法对气管镜管腔采样更有效;人工清洗环节非常重要,人工清洗后气管镜表面和管腔ATP总量建议低于10 000和3 400。     

2015-2018年湖北省全人群乙型病毒性肝炎免疫水平监测分析

目的 了解湖北省全人群乙型病毒性肝炎(简称乙肝)免疫水平,为制定乙肝的预防控制策略提供依据.方法 采用多阶段分层随机抽样方法,于2015-2018年选取湖北省8个市(15个县、45个社区)开展全人群乙肝表面抗原(HBsAg)和乙肝表面抗体(HBsAb)水平监测.结果 湖北省全人群HBsAg携带率为2.67％、HBsAb...     

甲醇-二硫化碳解吸-气相色谱法测定工作场所空气中1,2-二氯乙烯

目的 建立甲醇-二硫化碳解吸-气相色谱法测定工作场所空气中1,2-二氯乙烯的方法.方法 空气中1,2-二氯乙烯用活性炭管采集,经甲醇-二硫化碳溶剂解吸,DB-FFAP毛细管色谱柱(30mx0.25mm,0.25 μm)分离,火焰离子化检测器检测,保留时间定性,峰高或峰面积定量.结果 顺-1,2-二氯乙烯、反-1,2-二...     

空调公共场所的新风系统卫生状况调查

本文报道了对广州市内一些高档宾馆、大型商场和高档舞厅、卡拉ＯＫ厅的中央空调新风系统进行的调查，结果显示：新风系统设计欠完善，普遍忽视新风机房卫生管理等现象；新风量合格率较低；旅业为２７．２％，商场为３３％，舞厅、卡拉ＯＫ为２３．８％；新风不足，引起室内ＣＯ、ＣＯ２和细菌的污染。必须加强公共场所新风系统装置的预防性卫生监督、监测。本文并对评价娱乐场所空气质量指标提出作者的看法。     

三维超声在胎儿体表畸形诊断中的应用

目的探讨三维超声在胎儿体表畸形诊断中的应用价值。方法应用二维超声与三维超声相结合诊断孕中期胎儿体表畸形。结果三维超声诊断胎儿体表畸形共28例,单部位畸形19例、多部位畸形9例;其中无脑儿1例、唇裂13例、小下颌1例、脊柱裂4例、脐膨出2例、足内翻7例。结论三维超声能提供直观立体的胎儿体表结构图像,丰富诊断信息,是对二维超声成像技术的空间信息补充和完善,对胎儿体表畸形方面的诊断具有较高的应用价值。     

氢化可的松结肠靶向片包衣处方筛选及其释放机制研究

目的:筛选氢化可的松结肠靶向片的包衣处方,并考察其释放机制。方法:采用星点设计-效应面法优化氢化可的松结肠靶向片的包衣处方。以明胶-壳聚糖包衣(GC)层和聚丙烯酸树脂Eudragit L100包衣(E)层的包衣增质量为自变量,以靶向片在人工胃液、人工小肠液及人工结肠液的累积释放度(Q2 h、Q4 h、Q24 h)为因变量,分别进行多元线性和非线性拟合。根据绘制效应面选取最佳处方,并通过数学原理和相关模型探讨其释放机制。结果:GC层及E层包衣增质量最佳值分别为4%和20%;制备的3批氢化可的松结肠靶向片的平均Q2 h、Q4 h、Q24 h分别为0.16%、4.7%、93.35%;其释放符合一级动力学模型(r=0.984 5)。结论:根据筛选的包衣处方制备的氢化可的松结肠靶向片的体外释放符合缓释制剂要求。