CD+4 Foxp3+调节性T细胞对断烟大鼠肺部炎症及肺气肿的作用

目的 观察香烟暴露及断烟后大鼠Treg细胞的变化,探讨Treg细胞与断烟后大鼠肺部炎症反应和肺气肿持续存在的关系.方法 将50只雄性Wistar大鼠按随机数字表法分为5组:健康对照组、香烟暴露组和断烟组,其中健康对照组和香烟暴露组又分为12周组(对照1组和实验1组)和24周组(对照2组和实验2组).香烟烟雾暴露法建立大鼠肺气肿模型.HE染色观察大鼠肺气肿的改变,酶联免疫吸附法检测大鼠BALF中白细胞介素(IL-8)和肿瘤坏死因子-α(TNF-α)水平,流式细胞术检测大鼠外周血和肺实质中CD4+Foxp3调节性T细胞(Treg细胞)比例,实时定量PCR法检测大鼠外周血和肺实质中Foxp3的mRNA表达.多组间比较采用单因素方差分析,组内两两比较采用SNK和Games-Howell检验.结果 实验1组和实验2组平均内衬间隔(MLI)为(64.9±5.3)μm和(77.9±11.5)μm,均明显高于对照1组和对照2组的(39.0±3.8)μm和(40.3±2.7)μm,差异均有统计学意义(P＜0.01);断烟组MLI[(71.5 ±5.8)μm]介于实验1组和实验2组之间,但肺气肿程度较实验1组明显加重,差异有统计学意义(P＜0.01).实验1组和实验2组IL-8水平[(68±17)ng/L和(85±16)ng/L]及TNF-α水平[(14.1±1.8)ng/L和(20.1±8.7)ng/L]均明显高于对照1组和对照2组[(44±8)ng/L、(43±9)ng/L及(6.3±2.3)ng/L、(5.8±1.6)ng/L],差异均有统计学意义(P＜0.05).实验1组和实验2组肺实质中CD+4Foxp3+Treg细胞[(6.6±0.8)%和(5.3±0.9)%]明显少于对照1组和对照2组[(9.0±1.0)%和(9.6±0.9)%],差异均有统计学意义(P＜0.01);断烟组肺实质中CD+4Foxp3+Treg细胞[(7.2±0.6)%]与实验1组比较虽无明显减少,但未能恢复至正常水平.实验1组和实验2组肺实质中Foxp3的mRNA表达量(17±7和9±7)明显低于对照1组和对照2组(39±6和42±7),差异均有统计学意义(P＜0.01);断烟组肺实质中Foxp3的mRNA表达量(21±9)与实验1组比较未见明显减少,但未能恢复至正常水平.结论 香烟暴露肺气肿大鼠肺内调节性T细胞下调可能导致大鼠肺内炎症反应放大,并在断烟后持续存在,提示调节性T细胞下调可能是大鼠肺气肿持续进展的原因之一.     

香烟烟雾暴露对大鼠肺组织血小板衍生生长因子BB表达的影响

目的 研究烟雾暴露对大鼠肺组织血小板衍生生长因子BB(platelet derived growth factor-BB,PDGF BB)和核因子κB(nuclear factor-κB,NFκB) p65表达的影响,探讨烟雾暴露致大鼠肺动脉高压的发生机制.方法 雄性Wistar大鼠32只,随机分为对照组、烟雾暴露4、8、12周组,每组8只,制备各组烟雾暴露致肺动脉高压模型.RT-PCR方法检测PDGF-BB mRNA表达,免疫组织化学方法测各组大鼠肺组织PDGF-BB、NF-κBp65蛋白表达.结果 ①大鼠肺组织中PDGF BB mRNA相对表达量在烟雾暴露4周组(2.823±0.453)、8周组(4.015±0.052)、12周组(6.098±0.439)高于对照组(1.024±0.231),差异有统计学意义(P＜0.05);②大鼠肺组织中PDGF-BB蛋白相对表达量在烟雾暴露4周组(0.220±0.005)、8周组(0.367±0.004)、12周组(0.492±0.003)高于对照组(0.077±0.003),差异有统计学意义(P ＜0.05),NF-κBp65蛋白相对表达量在烟雾暴露4周组(0.330±0.003)、8周组(0.452±0.003)、12周组(0.596±0.003)高于对照组(0.186±0.001),差异有统计学意义(P＜0.05);③PDGF-BB蛋白的表达与PDGF-BB mRNA的相对表达量及与NF-κBp65蛋白的表达均呈正相关(r=0.686、r=0.501,P值均＜0.01).结论 烟雾暴露大鼠肺组织中PDGF-BB在转录和翻译水平表达均增高,且PDGF-BB和NFκB蛋白表达有相关性,提示PDGF-BB和NF-κB在烟雾暴露引起肺动脉平均压增高的过程中可能发挥了一定作用.     

香烟烟雾水溶物对小鼠的急性毒性和骨髓嗜多染红细胞微核率的影响

[目的]探讨香烟烟雾水溶物对雄性健康小鼠的急性毒性作用及其对骨髓嗜多染红细胞微核率的影响。[方法]以香烟烟雾水溶物为试验材料,用Horn's法测其LD50,进行小鼠骨髓嗜多染红细胞微核试验。[结果]该香烟烟雾水溶物的LD50为56.2 mg/kg,95%可信区间为33.8~82.5 mg/kg,按毒性分级标准,该水溶性提取物的毒性为中等毒;其低、中、高(1/8 LD50、1/4 LD50、1/2 LD50)剂量组的微核率分别为4.0‰、6.2‰、10.2‰,明显高于阴性对照组的1.8‰,并在一定范围内呈现明显的剂量-反应关系。[结论]香烟烟雾水溶物对小鼠有较强的急性毒性,属于中等毒,可引起小鼠骨髓嗜多染红细胞微核率增高,有一定的致突变作用。     

烟雾吸入性急性肺损伤/急性呼吸窘迫综合征的研究进展

目前烟雾吸入性急性肺损伤（ALI）／急性呼吸窘迫综合征（ARDS）的发病机制尚未完全明确,可能与烟雾所致的氧化性损伤、肺表面活性物质变化、细胞因子改变、细胞凋亡的发生有关。与机制相应的治疗方法仍未找到,常见的临床治疗方法（如：机械通气,肺泡灌洗,药物治疗）虽然已被证明有一定疗效,但仍然无法治愈烟雾吸入性ALI／ARDS。体外二氧化碳排除及一氧化氮治疗等新方法的尝试为我们进一步研究烟雾吸入性ALI／ARDS提供了新的思路。     

谷胱甘肽乙酯对烟雾吸入性肺损伤的作用

目的 探讨合成谷胱甘肽(GSH)的前体谷胱甘肽乙酯(GSEt)对大鼠烟雾吸入性肺损伤的影响.方法 按随机数字表法将60只雄性SD大鼠均分为正常组、模型组及GSEt低、高剂量组.建立烟雾吸入性肺损伤模型,GSEt治疗组分别于烟雾吸入后5 min腹腔注射GSEt 50 mg/kg和150 mg/kg.各组分别于伤后2、12、24 h取腹主动脉血进行血气分析;处死大鼠取肺,测定支气管肺泡灌洗液(BALF)中GSH活性;检测肺组织匀浆上清液中GSH、过氧化氢酶(CAT)及谷胱甘肽还原酶(GR)活性;制作肺组织病理切片,光镜下观察病理变化.结果 与正常组比较,模型组伤后各时间点动脉血氧分压(PaO2)、BALF中GSH活性及肺组织GSH、GR、CAT活性均显著下降.与模型组比较,GSEt高剂量组伤后12 h PaO2(mm Hg,1 mm Hg=0.133 kPa)显著升高(82.9±7.0比63.9±6.5,P＜0.05),伤后12h、24 h肺组织GSH活性(mg/g)显著升高(12 h:2.19±0.41比0.79±0.21,24 h:1.75±0.47比0.67±0.10,均P＜0.05);GSEt低剂量组伤后24 h和GSEt高剂量组伤后12h、24 h肺组织CAT活性(U/g)显著升高(低剂量组24 h:70.1±5.5比56.3±5.0;高剂量组12 h:90.9±8.1比67.9±6.1,24 h:94.7±7.7比56.3±5.0,均P＜0.05);GSEt高剂量组伤后24 h肺组织GR活性(mmol/g)显著升高(5.25±0.77比4.37±0.64,P＜0.05).光镜下观察伤后12 h GSEt高剂量组较模型组肺组织损伤程度明显减轻,炎性渗出减少,无明显出血.结论 GSEt治疗能够提高烟雾吸入性肺损伤肺组织抗氧化能力,对肺脏具有较好的保护作用.     

香烟烟雾提取物对培养的人皮肤成纤维细胞生长和增殖的影响

目的 探讨香烟烟雾提取物(CSE)对原代培养的皮肤成纤维细胞生长和增殖的影响.方法 采用噻唑蓝(MTT)比色法检测体外皮肤成纤维细胞存活力的影响,观察染毒后细胞形态和结构变化. β-半乳糖苷酶染色方法检测染毒后多次传代后成纤维细胞 β-半乳糖苷酶的变化情况.用分光光度法检测胞质内活性氧自由基(ROS)含量、超氧化物歧化酶(SOD)活性.结果 染毒后细胞呈典型的损伤形态,随着CSE浓度的增大和作用时间的延长,细胞存活力下降.长期染毒的细胞经5次传代后, β-半乳糖苷酶呈显著阳性;生长曲线示CSE作用后的细胞生长速度明显减慢.CSE作用于细胞后,细胞质内ROS含量升高(P<0.05),SOD活性降低(P<0.05).结论 CSE对体外培养的皮肤成纤维细胞增殖和生长有一定的抑制作用.低浓度CSE长期作用,可以促使原代培养的成纤维细胞迅速衰老.     

香烟烟雾致睾丸氧化应激损伤与iNOS表达的关系

目的:探讨诱导型一氧化氮合酶(iNOS)在香烟烟雾致睾丸生殖细胞氧化应激损伤中的关系以及抗氧化治疗的作用。方法:21只8周龄健康雄性SD大鼠制作吸烟染毒模型,随机平均分为3组:对照组(A)、吸烟组(B)、抗氧化治疗组(C)。测定睾丸组织匀浆中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)、一氧化氮(NO)、丙二醛(MDA)、一氧化氮合酶(NOS)及iNOS的含量。结果:吸烟组睾丸组织匀浆SOD、CAT活性增高,GSH-Px活性降低,MDA、NO含量增高,对照组与抗氧化组两者无差别。光镜下见吸烟组睾丸生精小管上皮细胞排列紊乱,生精细胞数量减少,小管腔内精子数量罕见,对照组与抗氧化组两者区别不大。免疫组织化学方法可见吸烟组大鼠睾丸的初、次级精母细胞中iNOS蛋白强阳性表达,在对照组与抗氧化组大鼠睾丸的初、次级精母细胞中iNOS蛋白呈弱阳性表达。结论:吸烟可导致大鼠睾丸氧化应激损伤;iNOS蛋白表达增加可能在吸烟引起睾丸生精上皮细胞氧化应激损伤中发挥重要作用;抗氧化治疗可减少iNOS蛋白在睾丸生精上皮细胞的表达,可减轻吸烟引起睾丸生精上皮细胞的氧化应激损伤。     

Impact assessment of WHO TobReg proposals for mandated lowering of selected mainstream cigarette smoke toxicants

The WHO Tobacco Product Regulation Study Group (TobReg) has proposed three regulatory models for cigarettes, each creating mandatory limits for emissions of nine smoke toxicants. One approach proposes country-specific limits, using median or 1.25× median toxicant/nicotine emission ratios. A second model provides fixed toxicant-ratio limits. The third model limits were three times the lowest toxicant emission on a market. Currently, the practical implications of these models are largely unknown.An impact assessment was conducted using cigarette data from 79 countries to identify four diverse test markets. We sampled all products from each market but limited product availability led to incomplete (80–97%) sourcing. Analysis showed that the country-specific model led to diverse (up to threefold) toxicant limits across the four markets. 70%–80% of products were non-compliant, rising to 100% in some countries with the second and the third models. With each regulatory model the main drivers of non-compliance were the tobacco-specific nitrosamines, the simultaneous application of limits for nine poorly correlated smoke toxicants, and analytical variability. Use of nicotine ratios led to compliance of some high toxicant emission products due to high nicotine emissions.Our findings suggest that these proposals would have greater impact on global markets than TobReg's stated aims.     

Affecting Factors of Secondhand Smoke Exposure in Korea: Focused on Different Exposure Locations

Exposure to secondhand smoke (SHS) not only can cause serious illness, but is also an economic and social burden. Contextual and individual factors of non-smoker exposure to SHS depend on location. However, studies focusing on this subject are lacking. In this study, we described and compared the factors related to SHS exposure according to location in Korea. Regarding individual factors related to SHS exposure, a common individual variable model and location-specific variable model was used to evaluate SHS exposure at home/work/public locations based on sex. In common individual variables, such as age, and smoking status showed different relationships with SHS exposure in different locations. Among home-related variables, housing type and family with a single father and unmarried children showed the strongest positive relationships with SHS exposure in both males and females. In the workplace, service and sales workers, blue-collar workers, and manual laborers showed the strongest positive association with SHS exposure in males and females. For multilevel analysis in public places, only SHS exposure in females was positively related with cancer screening rate. Exposure to SHS in public places showed a positive relationship with drinking rate and single-parent family in males and females. The problem of SHS embodies social policies and interactions between individuals and social contextual factors. Policy makers should consider the contextual factors of specific locations and regional and individual context, along with differences between males and females, to develop effective strategies for reducing SHS exposure.     

Hydroxocobalamin interference in routine laboratory tests: Development of a protocol for identifying samples and reporting results from patients treated with CyanokitTM

ObjectivesHydroxocobalamin (OHCob) is an antidote for cyanide poisoning in patients rescued from house fires and is known to cause interference with certain laboratory tests. Consensus is lacking on the extent of this interference and on how to handle these samples. The objectives of this study were to characterize OHCob interference across a wide range of laboratory tests and to develop protocols for identifying and reporting these samples.Designs & methodsPatient plasma samples (n = 5) were spiked with OHCob (1.5 mg/mL) and compared to controls without this drug. A series of analytes were measured using chemistry, urinalysis, coagulation, hematology, and blood gas instruments. Dose-response testing was performed on a subset of assays that showed interferences ≥10%.ResultsOf the 77 analytes evaluated, 27 (35%) showed interference from OHCob, with chemistry and coagulation analytes showing the greatest effects. Of those affected, 22 analytes had a positive interference, whereas 5 analytes had negative interference. Dose-response studies showed dose-dependent increases and/or decreases consistent with initial spiking studies. Although red in colour, plasma samples with OHCob did not trigger hemolysis index flags, necessitating a special sample identification and reporting protocol.ConclusionOHCob had significant effects on several analytes across different instruments. These findings led to the development of special sample handling and reporting protocols to identify OHCob samples and ensure only accurate results are released. It is vital for emergency departments to document and notify their laboratories whenever blood samples from these patients are drawn.