纳米SiO2与常规SiO2粉尘对大鼠肺脏器系数和羟脯氨酸含量影响的比较研究

目的比较纳米SiO2与常规SiO2粉尘对大鼠的肺脏脏器系数和羟脯氨酸含量的影响.方法分别用粒径为(10±5)nm的纳米级SiO2和粒径为0.5～10 μm的常规SiO2粉尘对雌性Wistar大鼠肺脏染尘,每鼠20 mg,于染尘后第30天和第60天测定动物肺脏脏器系数和羟脯氨酸含量.结果染尘后第30天、第60天纳米SiO2组大鼠肺脏脏器系数[(8.36±2.44),(7.22±0.92)]和羟脯氨酸含量[(2.45±0.39),(2.70±0.48)mg/g]均低于常规SiO2组,差异有显著性(P＜0.05或P＜0.01), 而与对照组相比差异未见显著性(P＞0.05).染尘后第60天纳米SiO2组大鼠全肺湿重[(2.00±0.23)g]低于常规SiO2组[(2.47±0.63)g], 差异有显著性(P＜0.05).结论纳米SiO2较常规SiO2粉尘致肺脏脏器系数和羟脯氨酸含量增加的程度轻.     

γ-干扰素对染石英尘大鼠肺纤维化的影响

目的　观察γ -干扰素 (IFN -γ)对染石英尘大鼠肺脏器系数及羟脯氨酸含量的影响 ,探讨γ -干扰素对实验性早期矽肺的防治作用。方法　一次性经气管给予雌性Wistar大鼠石英粉尘 2 0mg/只 ,染尘后第 2d开始每天给予γ -干扰素 (1× 10 5 IU/只 ) ,分别在 1个月和 2个月时处死动物。观察大鼠肺脏器系数、肺羟脯氨酸含量变化。结果　给予γ -干扰素 1个月及 2个月时 ,治疗组大鼠肺脏器系数与同期染尘对照组比较有所降低 ,但无显著性差异 ;而治疗组大鼠的肺羟脯氨酸含量均显著低于同期染尘对照组 (P <0 0 5)。结论　γ -干扰素可降低染石英尘大鼠肺羟脯氨酸含量 ,提示对矽肺纤维化具有一定的防治作用     

内质网应激性凋亡途径在粉尘致大鼠肺纤维化过程中作用研究

目的 研究内质网应激性凋亡途径在粉尘致大鼠肺纤维化过程中的作用.方法 36只健康成年雄性Wistar大鼠随机分为对照组及染尘组.采用非暴露式气管内注入法染尘,染尘组一次性注入含质量浓度为50 g/L粒径＜5μm石英粉尘的生理氯化钠溶液1 ml,对照组注入等体积无菌生理氯化钠溶液,每组分别于染尘结束后14、28、56 d随机处死6只大鼠,进行支气管肺泡灌洗,计算肺系数,羟脯氨酸法检测总胶原蛋白的水平,苏木精-伊红染色法观察肺组织的病理变化;流式细胞术检测肺泡巨噬细胞凋亡率;Western-blot法检测肺泡巨噬细胞Caspase-12的蛋白表达水平.结果 与对照组比较,染尘组大鼠在染尘后第14天细胞凋亡率和Caspase-12的蛋白表达水平均升高(P＜0.05);染毒后第28天肺系数及肺组织总胶原蛋白水平也升高(P＜0.05),细胞凋亡率和Caspase-12的蛋白表达水平持续升高(P＜0.05);染毒后第56天,以上指标仍进一步升高(P＜0.05).结论 内质网应激性凋亡途径可能参与了粉尘致大鼠肺纤维化的发病机制.     

纳米水镁石纤维的细胞毒性与致纤维化作用

目的　研究纳米水镁石纤维的细胞毒性与致纤维化作用。方法　收集Wistar大鼠肺泡巨噬细胞, 培养后分别加入纳米水镁石纤维、普通水镁石纤维、石英粉尘及生理盐水, 测定肺泡巨噬细胞存活率、乳酸脱氢酶(LDH)活力和酸性磷酸酶(ACP)活力。对大鼠经气管内一次注入上述各组粉尘悬液(每鼠1 ml,含粉尘50 mg), 分别于染尘后2, 4, 6个月处死大鼠, 测定大鼠肺湿重、肺干重、肺体积、肺胶原蛋白含量等指标, 并观察肺组织的病理改变。结果　纳米水镁石纤维组的细胞存活率为(62 40±8 48)%, 明显低于阴性对照组和普通水镁石纤维组(P<0 01), 而明显高于石英组(P<0 01); 纳米水镁石纤维2, 4, 6 月组的肺胶原蛋白含量分别为(48 78±10 69), (69 53±15 36), (80 65±13 95)mg, 与阴性对照组和普通水镁石纤维组相比, 差异无显著性(P>0 05), 而明显低于石英组(P<0 01)。结论　纳米水镁石纤维具有明显的细胞毒性, 其细胞毒作用较普通水镁石纤维强, 但明显要弱于石英粉尘; 致纤维化能力较弱, 与普通水镁石纤维无明显差异, 也明显弱于石英粉尘。     

纳米级与微米级二氧化硅粉尘对小鼠胚胎毒性的比较研究

目的比较研究纳米级(nm-)与微米级二氧化硅粉尘(μm-SiO2)对小鼠胚胎的影响,并观察胚胎Connexin32(Cx32)和Cx40基因有无点突变改变。方法5个实验组(零剂量粉尘组、μm-SiO250mg/m3组、μm-SiO2200mg/m3组、nm-SiO250mg/m3组、nm-SiO2200mg/m3组)共25只雌性小鼠,妊娠0日(E0)至E17日连续呼吸道染尘,观察妊娠期间母鼠体重变化,E18日取出胚胎,观察胚胎发育情况,并采用常规聚合酶链式反应(PCR)、聚合酶链式反应-单链构像多态性(PCR-SSCP)技术对胚胎的Cx32和Cx40基因进行点突变检测。结果E18日,各染尘组的母鼠体重均显著低于对照组;各染尘组的胚胎数、活胎数、胚胎体重显著低于对照组,nm-SiO2200mg/m3组活胎数显著低于nm-SiO250mg/m3组和μm-SiO2200mg/m3组,nm-SiO2200mg/m3组胚胎体重显著低于μm-SiO2200mg/m3组;nm-SiO2200mg/m3组死胎率和吸收胎率均显著高于对照组。Cx32和Cx40基因经检测未发现有突变者。结论SiO2粉尘具有小鼠胚胎毒性,微米级粒子粒径改变为纳米级后,毒性作用增强,且纳米级SiO2粉尘对小鼠胚胎有致死作用。两种粒径的二氧化硅粉体均未发现有致Cx32和Cx40基因点突变。     

实验性茶尘肺的研究

实验大鼠经气管滴注含３０ｍｇ茶尘的混悬液，３个月和６个月时分两批处死动物，观察肺的病理改变，发现染尘３个月组的肺湿重均值和肺胶原含量显著高于对照组，肺组织中可见０～Ｉ级异物巨噬细胞团，６个月组肺湿重和胶原含量与３个月组比较，无显著差别，但镜下可见Ⅱ级少量胶原纤维增生，茶尘实验线的病理改变较滴注石英粉尘组轻微，且进展缓慢。     

实验性茶尘肺的研究

实验大鼠经气管滴注含３０ｍｇ茶尘的混悬液，３个月和６个月时分两批处死动物，观察肺的病理改变，发现染尘３个月组的肺湿重均值和肺胶原含量都显著高于对照组，肺组织中可见０～Ⅰ级异物巨噬细胞团；６个月组肺湿重和胶原含量与３个月组比较，无显著差别，但镜下可见Ⅱ级少量胶原纤维增生。茶尘实验组的病理改变较滴注石英粉尘组轻微，且进展缓慢     

烟草尘致大鼠肺脏损伤的实验研究

Ｗｉｓｔａｒ大鼠随机分成３组。烟草尘组每只大鼠经气管注入４０ｍｇ经消毒的烟草尘，设置石英尘和生理盐水两个对照组。结果显示烟草尘组大鼠体重在染尘早期低于生理盐水对照组，全肺干重、全肺湿重、全肺胶原、血清铜蓝蛋白活性、血浆Ｄ－Ｄｉｍｅｒ含量均高于生理盐水对照组，但显著低于石英对照组。提示烟草尘对肺脏有一定毒作用和轻度致纤维化作用     

微米及纳米SiO2粉体的急性肺毒性比较

目的 比较纳米级SiO2与微米级SiO2粉体对呼吸道染尘大鼠的急性肺毒性.方法 雄性Wistar大鼠125只,按体重分为25组.呼吸道染尘剂量μm-SiO2分别为100(A组)、300 mg/m3(B组);nm-SiO2分别为100(A'组)、300 mg/m3(B'组).1次染尘2 h后,比较6、12、24、48、72 h支气管肺泡灌洗液(bronehoalveolar lavage fluid,BALF)中细胞总数(total cellular score,TCS)及分类、总蛋白(total protein,TPr)含量、碱性磷酸酶(alkaline phosphatase,AKP)和乳酸脱氢酶(lactate dehydrogenase,LDH)活性,血清和肺组织羟脯氨酸(hydroxyproline,HyP)含量.结果 染尘后6 h A'组BALF中TCS[(55.00±8.30)×104个/ml]、B'组BALF中TCS[(52.50±9.02)×104个/ml]均高于对照组[(34.88±12.53)×104个/ml];染尘后6、24 h A'组BALF中TCS[(55.00±8.30)×104个/ml、(39.75±12.08)×104个/ml]均高于等剂量微米SiO2染尘组[(32.38±13.07)×104个/ml、(24.13±10.97)×104个/ml].48 h A'组BALF中TPr[(0.34±0.09)g/L]、B'组BALF中TPr[(0.38±0.16)g/L]含量均高于等剂量微米SiO2染尘组[(0.20±0.07)g/L、(0.21±0.05)g/L].72 h A'组BALF中LDH活力[(1.66±0.22)×103 U/L]高于等剂量微米SiO2染尘组[(1.38±0.17)×103 U/L].6、24 h B'组BALF中AKP活力[(5.14±1.47)U/100 ml、(5.86±2.41)U/100 ml]均高于等剂量微米SiO2染尘组[(3.64±0.36)U/100 ml、(3.30±2.19)U/100 m1].6、12、48、72 h A'组肺组织HyP含量[(0.532±0.053)、(0.484±0.046)、(0.591±0.096)、(0.551±0.084)μg/mg肺湿重]以及12、72 h B'组肺组织HyP含量[(0.508±0.081)、(0.565±0.053)μg/mg肺湿重]均高于等剂量微米SiO2染尘组[(0.345±0.074)、(0.368±0.095)、(0.431±0.036)、(0.399±0.080)、(0.396±0.039)、(0.465±0.062)μg/mg肺湿重].结论 本实验条件下,与微米级SiO2粉尘相比,纳米级SiO2粉尘可导致较严重的急性肺毒性.     

尼龙六六盐粉尘对大鼠肺致纤维化实验研究

目的 研究尼龙六六盐粉尘对大鼠肺的致纤维化作用。方法 采用大鼠被动式粉尘吸入法染尘。以肺组织形态学改变为观察指标。并参考支气管肺泡灌洗（BAL）的实验结果。结果 实验组大鼠肺病理切片上可见轻度的网织纤维增生和少量胶原纤维，石英粉尘对照组可见明显的纤维化，两者差异有显著性，BAL实验组的各项指标实验组均高于正常对照组。低于石英粉尘组。结论 尼龙六六盐粉尘对大鼠肺有轻度的致纤维化作用。     

Development of silicotic lesions in the lungs of rats pre-exposed to coal fly ash.

The development of silicotic lesions was studied in the lungs of rats pre-exposed to a pulmonary load of coal fly ash. Exposure to quartz alone increased the wet weight, dry weight, and collagen content of the lungs. These changes were associated with an increase in the activity of lactate dehydrogenase, total proteins, and the cellularity of bronchoalveolar lavage. When the lungs of rats were pre-exposed to coal fly ash for 60 days and then exposed to quartz dust for periods similar to those used for exposure to quartz alone, the development of silicotic lesions and the laying down of collagen fibres was retarded, as judged by histopathological examination and biochemical analysis of the tissues for hydroxyproline contents. These changes in the lung tissue were associated with a significant reduction in the level of lactate dehydrogenase enzyme activity, total cell counts, and protein contents of the bronchoalveolar lavage derived from rats exposed to quartz.     

Development of silicotic lesions in the lungs of rats pre-exposed to coal fly ash

The development of silicotic lesions was studied in the lungs of rats pre-exposed to a pulmonary load of coal fly ash. Exposure to quartz alone increased the wet weight, dry weight, and collagen content of the lungs. These changes were associated with an increase in the activity of lactate dehydrogenase, total proteins, and the cellularity of bronchoalveolar lavage. When the lungs of rats were pre-exposed to coal fly ash for 60 days and then exposed to quartz dust for periods similar to those used for exposure to quartz alone, the development of silicotic lesions and the laying down of collagen fibres was retarded, as judged by histopathological examination and biochemical analysis of the tissues for hydroxyproline contents. These changes in the lung tissue were associated with a significant reduction in the level of lactate dehydrogenase enzyme activity, total cell counts, and protein contents of the bronchoalveolar lavage derived from rats exposed to quartz.     

褐煤尘细胞毒性和致纤维化作用

为了评价褐煤尘的细胞毒性及致纤维化作用，对２个褐煤矿的煤尘成分、体外细胞毒性、体内致肺损伤作用进行了研究。甲矿煤尘游离ＳｉＯ２含量为３．４％，乙矿煤尘为１．５％。培养液中加入褐煤尘后肺巨噬细胞存活率明显降低，乳酸脱氢酶（ＬＤＨ）和酸性磷酸酶（ＡＣＰ）活力明显增高。乙矿煤尘组细胞存活率明显低于甲矿煤尘组，ＬＤＨ明显高于甲矿煤尘组。染褐煤尘大鼠肺体积、湿重、干重和胶原蛋白含量增加，病理检查可见到煤尘灶、肺气肿、网状纤维和胶原纤维轻度增生。结果表明：褐煤尘具有细胞毒性和轻度致纤维化作用，乙矿煤尘细胞毒性和致纤维化作用均高于甲矿煤尘，用煤尘中元素含量解释煤尘毒性与以往的研究结果不尽相同。     

Laboratory testing of biological activity of ore mine dust: fibrogenicity, cytotoxicity, and hemolytic activity

The biological activity of respirable dust (particle size below 5 μm) from three ore mines was compared with its quartz content (14 to 36%) and with the occurrence of lung silicosis in miners. Three months after intratracheal instillation of 50 mg of dust suspensions, silicotic changes of the first and second degree (King's classification) developed in the lungs of rats. The content of hydroxyproline in the lungs increased by 60 to 110% in comparison to control values. No correlation was found between the quartz content of the dust and the histological changes or hydroxyproline levels. Cytotoxicity of the dust for guinea pig peritoneal macrophages and hemolytic activity in vitro for human erythrocytes did not correlate with its fibrogenicity. No new cases of lung silicosis have developed in the last 20 years in miners exposed in these ore mines to total dust concentrations below 10 mg/m³, although the incidence of silicosis was frequent in the past, when the dust concentrations were much higher.     

Pulmonary response to agate dust in vivo and cytotoxic and haemolytic effects in vitro.

The pulmonary response to agate dust in vivo was investigated and also its cytotoxic action on peritoneal macrophages and sheep erythrocytes in vitro. The results were compared with quartz dust as the known fibrogenic dust and emery dust (Corundum) was used as a control dust. Agate increased the wet and dry weight of lungs and induced increased collagen formation and a non-reversible fibrotic reaction in the lungs. The tissue response and lung changes were of milder intensity than seen in rats exposed to quartz. In vitro, the extent of dye-uptake and haemolysis yielded results similar to those of the in vivo studies. Release of lactic dehydrogenase into the culture medium was similar in both the agate and emery exposed cells but significantly less when compared with quartz treated cells.     

Pulmonary response to agate dust in vivo and cytotoxic and haemolytic effects in vitro

The pulmonary response to agate dust in vivo was investigated and also its cytotoxic action on peritoneal macrophages and sheep erythrocytes in vitro. The results were compared with quartz dust as the known fibrogenic dust and emery dust (Corundum) was used as a control dust. Agate increased the wet and dry weight of lungs and induced increased collagen formation and a non-reversible fibrotic reaction in the lungs. The tissue response and lung changes were of milder intensity than seen in rats exposed to quartz. In vitro, the extent of dye-uptake and haemolysis yielded results similar to those of the in vivo studies. Release of lactic dehydrogenase into the culture medium was similar in both the agate and emery exposed cells but significantly less when compared with quartz treated cells.     

Contrasting bronchoalveolar leukocyte responses in rats inhaling coal mine dust, quartz, or titanium dioxide: effects of coal rank, airborne mass concentration, and cessation of exposure

The aim of this study was to determine the bronchoalveolar leukocyte response to airborne coal mine dust; quartz and titanium dioxide were used as positive and negative controls, respectively. Groups of rats were exposed to airborne mass concentrations of 10 and 50 mg/m3 of the dusts for 7 hr/day, 5 days/week and their bronchoalveolar space was lavaged at time points between 2 and 75 days of exposure, to assess the leukocyte response. This study revealed time-dependent and airborne mass concentration-dependent recruitment of neutrophils and macrophages into the bronchoalveolar region with coal mine dust inhalation but no real difference in the magnitude of the response between coal mine dusts from collieries mining coal of different rank and quartz content although the maximum quartz content in the dusts used was 6%. The inflammatory response was much less than that produced by quartz, at similar airborne mass concentrations, and more than that produced by titanium dioxide which was, in general, a poor inflammogen in the rat lung. Groups of rats were exposed to the airborne dusts for 32 or 75 days, then removed from the exposure chambers, and allowed to recover by breathing room air for a further 64 days. During this recovery period there was marked progression of the leukocyte response with quartz and persistence of the response with coal mine dust. Chronic recruitment of leukocytes to the lungs of individuals inhaling coal mine dust is likely to be an important factor in the development of coal workers' pneumoconiosis.     

Microanalyses of lesions and lymph nodes from coalminers' lungs.

The dust content and composition of lesions and hilar lymph nodes from the lungs of British coalworkers have been examined. Samples of macules, fibrotic nodules, and massive fibrosis (both peripheral and central sites) were dissected from 49 lungs. The highest mean dust concentrations (about 20%) were found in nodules and massive fibrosis. Overall there were no significant differences between the selected lesion types and their respective whole lung dust composition, although the central sites of massive fibrosis were found to contain on average a higher proportion of coal and a lower proportion of ash and its measured constituents, quartz and kaolin plus mica, than the edge of the lesion (p less than 0.001 for each component). There were striking differences between recovered lung and lymph node dusts. An examination of 180 specimens showed a mean quartz in lymph node dust of 20.3% compared with 6.1% in lung dust. As expected the proportion of quartz was greater in lymph nodes and lungs from men who had worked "low" rank (high ash) coal. By contrast with the corresponding figures for lung dusts, however, the mean proportion of quartz in nodes did not increase over the pathological range of pneumoconiotic lung disease. On average the proportions of kaolin and mica in lymph nodes reflect those found in lungs. The lymphotrophic nature of quartz was clearly shown although it was not possible to show an association between this clearance pathway and any particular type of lesion.     

Microanalyses of lesions and lymph nodes from coalminers' lungs

The dust content and composition of lesions and hilar lymph nodes from the lungs of British coalworkers have been examined. Samples of macules, fibrotic nodules, and massive fibrosis (both peripheral and central sites) were dissected from 49 lungs. The highest mean dust concentrations (about 20%) were found in nodules and massive fibrosis. Overall there were no significant differences between the selected lesion types and their respective whole lung dust composition, although the central sites of massive fibrosis were found to contain on average a higher proportion of coal and a lower proportion of ash and its measured constituents, quartz and kaolin plus mica, than the edge of the lesion (p less than 0.001 for each component). There were striking differences between recovered lung and lymph node dusts. An examination of 180 specimens showed a mean quartz in lymph node dust of 20.3% compared with 6.1% in lung dust. As expected the proportion of quartz was greater in lymph nodes and lungs from men who had worked "low" rank (high ash) coal. By contrast with the corresponding figures for lung dusts, however, the mean proportion of quartz in nodes did not increase over the pathological range of pneumoconiotic lung disease. On average the proportions of kaolin and mica in lymph nodes reflect those found in lungs. The lymphotrophic nature of quartz was clearly shown although it was not possible to show an association between this clearance pathway and any particular type of lesion.     

Biological effects of the respirable dusts from ore mines

The biological effects of ore dusts were examined on peritoneal macrophages in vitro and on rat lung in vivo. The methylene blue adsorption of the dust samples, cytotoxicity, and phospholipid and hydroxyproline content of the lung were determined. It was realized that the examined ore samples had cytotoxic effects and from the in vitro results one can get information about the type of damage to be expected in the lung tissue. It is supposed that the examined ore dusts are less dangerous and slower acting than quartz, but they cause progressive fibrosis. The in vivo biochemical experiments do not give information about the type of damage to be expected in lung tissue; and the data on ore, bentonite, and coal do not differ from each other. To determine the typical biochemical changes caused by quartz, we obtain the most valuable information by determination of lung weight and phospholipid, phosphatidylcholine, and hydroxyproline content.