浓缩鱼油对实验性动脉粥样硬化的影响及机理探讨

本文观察了浓缩鱼油（ＣＦＯ）对实验性动脉粥样硬化（ＡＳ）形成、血浆及组织胆固醇含量变化、血浆高密度脂蛋白胆固醇（ＨＤＬ一Ｃ）及其代谢酶活性、血小板分泌产物、血液流变学及培养的主动脉平滑肌细胞（ＳＭＣ）增殖的影响。结果显示，ＣＦＯ对实验性ＡＳ形成具有非常显著的抑制作用；ＣＦＯ降低血浆总胆固醇（ＴＣ），同时阻止ＴＣ蓄积于动脉壁和肝脏，ＣＦＯ升高血浆ＨＤＬ一Ｃ，机制是刺激ＨＤＬ合成酶及抑制其降解酶活性；ＣＦＯ抑制血小板分泌血栓素Ａ２（ＴＸＡ２）、５一羟色胺（５一ＨＴ）及钙离子，促进其自身合成环磷酸腺替（ｃＡＭＰ）；ＣＦＯ通过降低血脂和纤维蛋白原水平使全血粘度降低；ＣＦＯ对体外培养的主动脉ＳＭＣ增殖具有显著的抑制作用。     

急性缺氧和缺氧习服对冻伤大鼠直肠温度和冻足皮肤温度的影响

本文报告了急性缺氧和缺氧习服对冻伤大鼠直肠温度和冻足皮肤温度的影响。结果显示，平原冻伤（ＦＮ）组在冷冻与复温过程中，大鼠直肠温度（Ｔｒ）不变或升高；冻足皮肤温度（Ｔｓ）在冻后１～２天升至高峰，随后降低，冻后６～７天降至接近未冻足水平。在模拟６０００ｍ缺氧条件下，大鼠冷冻前、后的Ｔｒ均降低，但急性缺氧冻伤（ＦＡＨ）组较４ｈ／天连续４周缺氧习服大鼠的缺氧冻伤（ＦＨＡＣ）组降低更明显；复温过程中ＦＡＨ组Ｔｒ继续降低，而ＦＨＡＣ组Ｔｒ不再下降。冻后冻足Ｔｓ变化：ＦＡＨ组与ＦＮ组接近；ＦＨＡＣ组冻后２天内稍升高，随之快速降低，冻后７天仍低于未冻侧。上述结果表明，缺氧使大鼠呈现低体温，缺氧复合一定强度冷刺激使低体温加重；缺氧习服可相对减轻缺氧性低体温的程度，但冻足Ｔｓ减低，外周组织抗冻力减弱。     

维生素A及维生素C对肺巨噬细胞产生活性氧及细胞因子的影响

目的 为观察维生素Ａ（ＶＡ）及维生素Ｃ（ＶＣ）对肺巨噬细胞（肺Ｍφ）功能的影响。方法 以大鼠 动物模型观察ＶＡ及ＶＣ对大鼠肺Ｍφ产生自由基（Ｏ２，Ｈ２Ｏ２）及细胞因子（ＩＬ－１，ＴＮＦ－α）的影响。结果 补充ＶＡ及ＶＣ均明显增加肺Ｍφ的吴噬功能及Ｏ２、Ｈ２Ｏ２的产生；补充ＶＡ可明显增加细胞因子（ＩＬ０－１，ＴＮＦα）的产生，而补充ＶＣ效果不明显。结论适当补充ＶＡ可活化肺Ｍφ的吞噬功能及Ｏ２、Ｈ２Ｏ     

学校图书馆甲醛污染状况调查

对某高校图书馆进行甲醛及其它卫生学指标的调查测定，结果表明：图书馆内甲醛浓度书库最高；工作室次之，阅览室较低，但三者均比室外高；开窗后一定时间，甲醛浓度显著降低；温度，ＣＯ、ＣＯ２等指标符合图书馆卫生标准，而湿度偏高，气流较低。馆内工作人员及读者有多方面不良健康效应。     

EG核磁共振机房中央空调紧急抢修一例

我院的ＧＥ核磁共振中央空调为意大利产ＶＡＬＬＥＳＡＬＩＭＢＥＮＥＣＰＡＶＩＡＲＣＣＯＮＤＩＺＩＯＮＡＴＯＲＩ产品。该机采用双压缩机自动循环工作 ,单片机控制温度、湿度、压缩机压力等参数。具有全程自动监控启动时间、压缩机工作时间 ,电源电压自动保护 ,室外风机自动调速 ,室内风机自动过温保护 ,以及温度、湿度控制曲线斜率设置等多种功能。整个核磁共振共有 3台机组 ,第一台控制机房温度和湿度 ,控制在 2 0℃ ,相对温度 4 5 % ;另一台控制液氦压缩机 ;第三台控制诊断室内温度。故障现象 :三台空调同时报警 ,但一直未停机 ,所以…     

急性铬化物暴露肺损伤的剂量效应与时间过程

经一次气管灌注不同剂量可溶性六价铬酸钠（Ｎａ２ＣｒＯ４）后第２天和一次灌注０．９８ｍｇ·ｋｇ－１Ｎａ２ＣｒＯ４后不同时间，观察了ＳＤ大鼠支气管肺泡灌洗液（ＢＡＬＦ）和血液生化改变的剂量效应与时间过程。结果表明，Ｎａ２ＣｒＯ４的无效应剂量与阈剂量分别为０．００８和０．０４ｍｇ·ｋｇ－１，染毒剂量≥０．２０ｍｇ·ｋｇ－１时，ＢＡＬＦ中绝大多数生化参数呈现显著的剂量依赖性增加；严重中毒剂量（≥０．９８ｍｇ·ｋｇ－１）可引起ＢＡＬＦ和血液中几乎所有测试参数的显著增加，这种现象约持续一周，至少需要４周才能恢复正常。分析本次研究结果，可得出以下结论：≥０．９８ｍｇ·ｋｇ－１的Ｎａ２ＣｒＯ４可导致包括肺内细胞损伤、弥漫性肺泡炎和肺水肿在内的急性肺损伤；Ｎ－乙酰－β－Ｄ－氨基葡糖苷酶（ＮＡＧ）、溶菌酶（ＬＹＳ）、碱性磷酸酶（ＡＬＰ）、白蛋白（ＡＬｂ）和血管紧张素转换酶（ＡＣＥ），可能是评价接触较低剂量Ｎａ２ＣｒＯ４（＜０．９８ｍｇ·ｋｇ－１）后所致急性肺损伤的最有价值的早期敏感指标     

脱氧雪腐镰刀菌烯醇,黄曲霉毒素G1对体外培养人外周血淋巴细胞凋？…

以细胞培养、流式细胞义ＤＮＡ含量分析及ＤＮＡ琼脂糖凝胶电泳方法研究了我国食管癌高发区磁县居民粮食中优势污染霉菌毒素脱氧雪腐镰刀菌烯醇（ＤＯＮ）和黄曲霉毒素Ｇ１（ＡＦＧ１）对人淋巴细胞凋亡的影响,流式细胞术（ＦＣＭ）检测结果显示,ＤＯＮ、ＡＦＧ１处理组淋巴细胞出现了典型的亚二倍体凋亡细胞峰,凋亡百分率与毒素作用时间（ＤＯＮ,２－７２小时;ＡＦＧ１;２－２４小时）及测量（ＤＯＮ;５０－２０００μｇ／Ｌ     

茶油延缓动脉粥样硬化形成及其机理的探讨

本文报告了富含单不饱和脂肪酸（ＭＵＦＡ）的茶油对动脉粥样硬化（ＡＳ）形成及脂质代谢、血栓素Ｂ２（ＴＸＢ２）和脂质过氧化物（ＬＰＯ）的影响。结果提示，茶油具有明显的延缓ＡＳ形成的作用；其机理可能是茶油中富含的ＭＵＦＡ纳入组织后，通过降低血脂、肝脂，升高ＨＤＬ一Ｃ／ＴＣ比值，抑制ＴＸＢ２释放，增加机体抗氧化酶ＳＯＤ和ＧＳＨ一Ｐｘ的活性，降低血浆、肝脏ＬＰＯ生成等环节而发挥作用。因此，我国特产的茶油对防治冠心病（ＣＨＤ）有益，值得开发利用。     

全氟化碳对兔肺泡巨噬细胞吞噬及杀菌功能的影响

目的 观察全氟化碳（ＰＦＣ）对兔肺泡巨噬细胞（ＡＭ）吞噬功能及产生过氧化氢（Ｈ２Ｏ２）能力的影响。方法 健康新西兰白兔放血处死后通过全肺灌洗获取ＡＭ，分为对照组和实验组，实验组ＡＭ暴露于全氟萘烷（ＦＤＣ），观察两组ＡＭ的吞噬功能及产生Ｈ２Ｏ２的能力。结果 ＦＤＣ能明显降低ＡＭ的吞噬率、吞噬指数和产生Ｈ２Ｏ２的能力。结论 ＦＤＣ能干扰ＡＭ的正常功能，从而可能降低肺局部对病原微生物的防御能力。     

活性碳纤维动态吸附SO_2、NO_2和NH_3气效率与影响因素的研究

本文研究了粘胶基活性碳纤维(ACF)对SO_2、NO_2和NH_3气体的动态吸附,考察了浓度、流速、温度,湿度及ACF再生次数对吸附效率的影响。结果表明ACF对SO_2、NO_2和NH_3气体的吸附作用以物理吸附为主,但存在一定程度的化学吸附。ACF吸附SO_2、NO_2和NH_3气体的饱和吸附量分别为9.4mg/g,151.4mg/g和13.7mg/g。     

A study on the relative breakthrough time (RBT) of a respirator cartridge for forty-six kinds of organic solvent vapors

The breakthrough time of a commercially available respirator cartridge was measured for 46 kinds of organic solvents. The condition of the test air flow was set according to the Japanese government standard for the National Approval Test: at 300 ppm of an organic solvent vapor concentration, a temperature of 20 degrees C, a relative humidity of 50 percent, and a flow rate of 30 L/min. The interval between the start of passing the test flow through a cartridge and the time when the concentration of organic solvent vapors at the downstream of the cartridge reached 5 ppm was measured. The ratios of breakthrough times of organic solvents to that of cyclohexane which is designated as the standard test vapor in Japan, were calculated to obtain the relative breakthrough times (RBTs). Nine of the 46 organic solvents had breakthrough times shorter than that of cyclohexane, and these organic solvents with shorter RBTs were characterized by low boiling points and small molecular weights. The RBTs of 34 organic solvents were compared with the breakthrough times reported by Nelson et al. The relationship between the RBTs of this experiment and those reported by Nelson correlated well (correlation coefficient: 0.861).     

Efficiency of respirator canisters with methyl bromide

Two kinds of respirator canisters, an organic vapor (OV) canister containing activated carbon and a methyl bromide (MB) canister containing activated carbon impregnated with triethylenediamine were investigated for their filtration efficiency of MB gas under various conditions of MB concentration, humidity and temperature. At lower MB concentrations, the breakthrough time of the OV canister was shorter than that of the MB canister. It also decreased with an increase in temperature, whereas the breakthrough time of the MB canister did not change with temperature. Humidity affected the breakthrough times of the OV canister as much as those of the MB canister. The desorption and the remaining filtration efficiency of MB gas were examined in both canisters which had been used for fumigation in plant quarantine. More than 5 ppm of MB gas leaked from 11 out of 18 used OV canisters, whereas less than 0.1 ppm MB leaked out from each of the used MB canisters. The mean remaining breakthrough time of the used OV canisters was 9.3 min, whereas that of the used MB canisters was 74.4 min. From the present study, it was shown that the gas masks with the OV canisters were not suitable for fumigating with MB gas.     

Evaluation of a sampling method for the measurement of occupational exposures to ethylene

In an effort to assess the scope of occupational exposures to ethylene, the Olefins Panel of the American Chemistry Council designed and conducted a research project to develop and apply a sampling and analytical method to measure workplace exposure. The method uses packed Carbosieve S-III thermal desorption tubes (Supelco, Bellefonte, Pa.) with a low sample collection flow rate. The tubes were analyzed by thermal desorption gas chromatography. The methodology was validated for both 15-min short-term exposure limit and 8-hr time-weighted average (TWA) samples in the laboratory prior to the field study. The effects of varying sampling flow rate (2, 5, 10, and 25 mL/min) and temperature (25 and 35 degrees C) on sample breakthrough time were assessed at a constant relative humidity of 90%. Breakthrough times decreased linearly with sampling flow rate and temperature. The optimal sampling flow rate and temperature at 90% relative humidity were 2 mL/ min and 25 degrees C. A full-shift TWA sample can be collected using two tubes for up to 4 hours each at a flow rate of 2 mL/min, while a STEL sample can be collected at 25 mL/min flow rate. The evaluation indicated samples can be stored under ambient conditions for a period up to 14 days without significant sample loss. Field measurements were performed at 14 petrochemical facilities within North America. The mean 8-hour TWA ethylene concentration (71 sample pairs) was 2.6 ppm (range: <0.05 to 2100 ppm). Significant ethylene concentrations were observed for only two of the 73 TWA sample pairs. Each of these two samples was obtained from the same facility, and only one tube of the sample pairs showed a high ethylene concentration (3200 ppm and 4200 ppm, respectively) for the 1600 ppm and 2100 ppm TWA sample. The first tube of each of these two sample pairs showed no detectable levels. Further, 69 of 71 sample pairs had TWA concentrations below 13 ppm. The mean of 26 short-term exposure limit samples was 16 ppm (range: <0.05 to 63 ppm), with only one sample above 50 ppm. The results of this study indicate that airborne concentrations of ethylene can be effectively measured using Carbosieve S-III packed thermal desorption tubes under typical workplace conditions.     

低浓度挥发性有机化合物被动式个体采样器的研究

研制了扩散式挥发性有机化合物（ＶＯＣｓ）个体采样器,适用于对环境空气中和非职业性个体接触ＶＯＣｓ的监测。在风速１０～２６０ｃｍ／ｓ,相对湿度为３０％～８０％,温度为１０～３０℃的范围内使用,采样速率分别为苯：２５．７４ｍｌ／ｍｉｎ,甲苯：２５．１６ｍｌ／ｍｉｎ,四氯乙烯：２５．８５ｍｌ／ｍｉｎ,对－二甲苯：８．１６ｍｌ／ｍｉｎ,苯乙烯：６．４７ｍｌ／ｍｉｎ。与主动式活性炭纤维（ＡＣＦ）管采样法比较,本个体采样器测定空气中靶ＶＯＣｓ的总不确定度均在±２５％以内。     

Permeation of neoprene protective gloves by acetone: comparison of three different permeation cells in an open-loop system

The increased interest in protective capacity of chemical protective clothing materials has resulted in an increasing number of reports from permeation testing, performed by various test procedures and with permeation cells of different configurations. To make it possible to compare the resultant data, it is necessary to identify what parameters will have a decisive influence on test results. The influence of various carrier gas flow rates on breakthrough time and permeation rate of acetone through gloves made of neoprene was investigated using three permeation cells of different configurations. The breakthrough times were not influenced by cell design or gas flow rate. On the other hand, both cell configuration and gas flow rate influenced the steady-state permeation rate.     

Chemical cartridge respirator performance: 1,3-butadiene

The chemical 1,3-Butadiene recently has been classified as a potential occupational carcinogen; subsequently, a reduction in the 8 hr TWA from 1000 ppm to 10 ppm has been proposed. Substantial quantities of 1,3-Butadiene are produced annually for use in the manufacture of a variety of rubber compounds, foams, resins and chemicals. Existing process environments may present a potential health hazard under the proposed standards, and the need for proper respiratory protection is evident. As a result, the performance of Scott organic vapor (642-OV), organic vapor/acid gas (642-OA) and acid gas (642-AG) twin cartridges has been determined for 1,3 butadiene. A cartridge test system was developed to generate challenge concentrations of 100 ppm and 1000 ppm; an infrared analyzer was used to measure breakthrough at 10 ppm. The residence time modeling concept developed previously was used to produce the performance characteristics for three types of activated carbon for residence times of 0.1 less than or equal to tau less than or equal to 1.0 sec. Kinetic adsorption capacities and adsorption rate constants were computed from this data, and cartridge performance also was predicted. The twin cartridges tested demonstrated reasonable adsorption capacity for 1,3 butadiene. Cartridge service life was found to be inversely proportional to airflow rate; it was reduced at elevated temperature and humidity conditions. Breakthrough times were approximately three times longer at 100 ppm than at 1000 ppm. When clean air was drawn through cartridges saturated with 1000 ppm 1,3 butadiene, desorption occurred readily. The rate of desorption and the peak concentration were found to be dependent upon the temperature, humidity and degree of saturation.     

Development of a new respirator for organic vapors with a breakthrough detector using a semiconductor gas sensor

A method for determining breakthrough of organic vapors in a respirator cartridge was developed. A thick film semiconductor gas sensor was used as a breakthrough detector. Air containing organic vapor was introduced into the cartridge, and an output signal from the sensor inserted in the downstream flow of the cartridge was recorded on an IC card. Simultaneously, the breakthrough curve was obtained by measuring the vapor concentration at downstream from the respirator cartridge with a gas chromatograph (GC) equipped with a flame ionization detector. When the breakthrough was almost completed, the data recorded in the card were transferred to a personal computer and the change in the output signal from the sensor was compared with the breakthrough curve obtained by the GC. Twelve organic solvents including aromatic hydrocarbons, chlorinated hydrocarbons, acetates, alcohols, ketones, and aliphatic hydrocarbons were tested under low (20%-25%) and high (70%-80%) relative humidity ranges. The sensitivity of the sensor for chlorinated hydrocarbons such as 1,1,1-trichloroethane was relatively low, especially when the relative humidity was high, but the rise time of the sensor output signal was almost the same as or earlier than the breakthrough time by the GC. Based on the experimental results, a new respirator for organic vapors that can detect the end of service life was developed.     

An evaluation of respirator canisters to acrylonitrile vapors

Experimental breakthrough times obtained from evaluating respiratory canisters to acrylonitrile vapors at various concentrations are presented and compared to estimated breakthrough times calculated from Nelson's equation for organic vapors adsorbed on activated carbon. The slope of the regression for breakthrough time vs. concentration of acrylonitrile was found to compare closely to that derived from Nelson's equation in the concentration range from 30 to 1000 ppm. This demonstrates that the equation is capable of predicting breakthrough times for organic compounds which, like acrylonitrile, have low molecular weights and boiling points. This ability to predict service life is also influenced by other important factors such as relative humidity and amount of activated carbon packed in a canister. Results of this evaluation illustrate the need to determine breakthrough times for compounds under controlled conditions similar to those encountered in the field, especially at low concentrations. Industrial hygienists should use experimentally derived breakthrough times to predict the service life of an air purifying device if they are available.     

Absorption of L-histidine and glucose from the jejunum segment of the pig and its diurnal fluctuation.

1. Flow rate of digesta and its component in the upper jejunum, and the absorption of L-histidine and glucose from the jejunum segment were measured in pigs fitted with three simple cannulas. The pigs were fed once faily at 08.30 hours. 2. Maximum flow of digesta was obtained in the period 10.00-10.30 hours; the flow rate decreased with time after feeding, reaching a minimum in the period 22.00-22.30 hours. 3. The absorption rate for L-histidine and glucose increased in a hyperbolic manner with increasing concentrations of infused test material, which ranged from 2.5 to 20 g/1 for each material. 4. L-histidine and glucose were absorbed nearly independently when perfused in combination. The absorption rates for glucose were significantly (P less than 0.01) greater than the corresponding rates for L-histidine at each concentration of infusate. 5. The absorption of both L-histidine and glucose expressed as a percentage of the amounts in the perfusate decreased with increasing flow rate of perfusate, from 400 to 800 ml/h. The increase in flow rate from 400 to 800 ml/h was associated with a 20% increase in L-histidine absorption rate; there was a 30% increased in glucose absorption rate when the flow rate was increased to 600 ml/h, but no further incrase at 800 ml/h. 6. The absorption of both L-histidine and glucose decreased with time after feeding; the absorption rates for L-histidine and glucose measured for the period 10.00-22-30 hours were 126 and 133%, respectively, of those measured for the period 22.00-22.30 hours.     

Cyclohexane as an alternative vapor of carbon tetrachloride for the assessment of gas removing capacities of gas masks

An alternative vapor was explored to replace carbon tetrachloride (CCl4) for testing breakthrough times of cartridges and canisters of gas masks in the National Approval Test of Respirators. Cyclohexane was single out as a candidate for the alternative vapor out of six vapors: trichloroethylene, n-pentane, n-hexane, n-heptane, toluene and cyclohexane from the viewpoints of similarity of vapor pressure and water-solubility to CCl4, lower toxicity than CCl4, and technical feasibility in generating an airflow of 30 L/min containing the vapor ranging from 300 to 5000 ppm. Breakthrough times of cartridges and canisters were examined by generating cyclohexane vapor in a test airflow of 30 L/min in comparison with CCl4 vapor under various test conditions with different vapor concentrations and relative humidities (RH). As the results, the breakthrough times of the cartridges and canisters for cyclohexane were found to almost coincide with those for CCl4 under all examined range of concentrations and RH. By an increase of humidity from 50% RH to 80% RH, the cartridges showed significant shortening of breakthrough times for both of CCl4 and cyclohexane, but the susceptibility of the breakthrough time of cyclohexane to humidity was also similar to that of CCl4. It was, therefore, concluded that cyclohexane can be recommended as the alternative vapor of CCl4 for testing the breakthrough times of gas mask cartridges and canisters in the National Approval Test.