Fine particulate matter and incidence of metabolic syndrome in non-CVD patients: A nationwide population-based cohort study

Background

It has been reported that particulate matter (PM) is associated with cardiovascular diseases (CVD) while metabolic syndrome is also an important risk factor for CVD. However, few studies have investigated the epidemiological association between PM and metabolic syndrome.

Maternal exposure to ambient PM2.5 and term low birthweight in the State of Georgia

A growing body of evidence suggests that ambient air pollution could be associated with low birthweight (LBW). In this study, we examined pregnancy exposure to ambient PM_2.5 and the risk of LBW in the State of Georgia. The study population consisted of 48,172 full-term live births between 1 January 2004 and 31 December 2004 in nine counties of Georgia, which was obtained from the national natality dataset. County-level air quality index data obtained from the U.S. Environmental Protection Agency was used to estimate exposure to ambient levels of PM_2.5. Multivariate logistic regression revealed that infants with maternal exposure to PM_2.5 falling within 75 to < 95th percentiles were at increased risk of LBW (OR: 1.36; 95 % CI: 1.03, 1.79), after adjusting for potential confounders. This study provided more evidence on the role of PM_2.5 in LBW. Reducing exposure for pregnant women would be necessary to improve the health of infants.     

电设备应用策略管理对层流手术室PM2.5及切口感染的影响

目的探讨电设备应用策略管理对层流手术室PM2.5及切口感染的影响。方法将200例患者按是否实施层流手术室电设备应用策略管理分为两组,每组100例。对照组采用层流手术室电设备常规管理,管理组在对照组基础上采用层流手术室电设备应用策略管理,统计两组术中手术室内人员数、手术时间、术中出血量、术后切口感染发生情况,检测患者切口及口鼻周围PM2.5浓度。结果两组术中手术室内人员数、手术时间、术中出血量比较差异无统计学意义(P>0.05)。管理组距离切口1 cm、5 cm、10 cm、20 cm和距离患者口鼻5 cm处PM2.5浓度显著低于对照组(P<0.01),切口感染率显著低于对照组(P<0.05)。切口感染患者距离切口1 cm、5 cm、10 cm、20 cm和距离患者口鼻5 cm处PM2.5浓度显著高于无切口感染患者(P<0.05)。相关分析显示,层流手术室PM2.5浓度与切口感染率呈显著正相关(P<0.05)。结论电设备应用策略管理有助于降低层流手术室PM2.5浓度及切口感染发生率。     

多发性肌炎/皮肌炎治疗研究进展

多发性肌炎/皮肌炎(polymyositis,PM/dermatomyositis,DM)是以侵犯骨骼肌为主,可累及肌肉、肺、肾等多个脏器的自身免疫性疾病,其临床表现复杂,患者多因肺间质病变、肿瘤等并发症死亡,治疗以糖皮质激素为主,以及免疫抑制剂、生物制剂等,但不良反应大,对相关并发症的效果不理想。而干细胞移植治疗是作为当前治疗难治性PM/DM的一种手段。本文从PM/DM的治疗现状出发进行综述,以期为PM/DM临床治疗提供更多参考。     

空气细颗粒物暴露水平与健康成人大脑灰质体积和认知功能的关联研究

目的:应用磁共振成像(MRI)技术探究空气细颗粒物PM2.5暴露水平对健康成年人大脑灰质体积(GMV)和认知功能的影响。方法:选取487例健康成人,采集一般人口学信息及详细居住信息,并根据居住信息获取各受试近6个月和8岁～15岁期间的PM2.5暴露水平,对所有研究对象完成高分辨率结构MRI扫描,使用中文版精神分裂症认知功能成套测验-共识版(MCCB)进行认知测查,使用相关和回归分析探索空气PM2.5暴露水平与GMV和认知功能的关联。结果:近6个月PM2.5暴露水平与大脑右侧额下回三角部(brodmann分区[BA] 45)和右侧颞中回(BA 22)GMV存在负性关联(FWE校正,P<0.05,团块>10体素);与MCCB认知评估的信息处理速度-连线测试(r=-0.17,P<0.01)和推理和问题解决-迷宫测验评分(r=-0.22,P<0.01)负相关。8～15岁时的累积空气PM2.5暴露量与左侧梭状回(BA 18)和右侧舌回(BA 17)GMV负相关(FWE校正,P<0.05,团块>10体素),且与信息处理速度-连线测试、推理和问题解决-迷宫测验评分...     

Nasal epithelial barrier disruption by particulate matter ≤2.5 μm via tight junction protein degradation

Upper airway diseases including sinonasal disorders may be caused by exposure to fine particulate matter (≤2.5 μm; PM2.5), as proven by epidemiological studies. PM2.5 is a complex entity whose chemical constituents and physicochemical properties are not confined to a single, independent “particle” but which in this study means a distinctive environmental “toxin.” The mechanism whereby PM2.5 induces nasal epithelial barrier dysfunction leading to sinonasal pathology remains unknown. In the present study, human nasal epithelial cells were exposed to non‐cytotoxic doses of PM2.5 to examine how PM2.5 affects the nasal epithelial barrier. Tight junction (TJ) integrity and function were assessed by transepithelial electric resistance and paracellular permeability. The expression levels of TJ proteins such as zona occludens‐1, occludin and claudin‐1 were assessed by immunofluorescence staining and western blot. PM2.5 exposure induced epithelial barrier dysfunction as reflected by increased paracellular permeability and decreased transepithelial electric resistance. TJ proteins zona occludens‐1, occludin and claudin‐1 were found to be downregulated. Pretreatment with N‐acetyl‐l ‐cysteine alleviated PM2.5‐mediated reactive oxygen species generation in RPMI 2650 cells, further preventing barrier dysfunction and attenuating the degradation of TJ proteins. These results suggest that PM2.5 induces nasal epithelial barrier disruption via oxidative stress, and N‐acetyl‐l ‐cysteine counteracts this PM2.5‐mediated effect. Thus, nasal epithelial barrier disruption caused by PM2.5, which leads to sinonasal disease, may be prevented or treated through the inhibition of reactive oxygen species.     

Resveratrol relieves particulate matter (mean diameter < 2.5 μm)‐induced oxidative injury of lung cells through attenuation of autophagy deregulation

Oxidative stress and inflammation are critically implicated in ambient fine particulate matter (mean diameter < 2.5 μm; PM_2.5)‐induced lung injury. Autophagy, playing a crucial role in various physiopathological conditions, modulates cellular homeostasis and stress adaptation. Resveratrol is a phytoalexin that exerts potent antioxidant effects on cardiopulmonary diseases. To date, the mechanisms by which resveratrol protects against PM_2.5 remain to be elucidated. In the present study, we investigated the effect of resveratrol on PM_2.5‐induced oxidative injury. The potential role of nuclear factor erythroid‐2‐related factor 2 and autophagy in this progress was explored. Human bronchial epithelial cells were treated with PM_2.5 and the cytotoxicity and oxidative stress markers were determined. The results showed that PM_2.5 decreased cell viability and elevated the level of lactate dehydrogenase. The levels of malondialdehyde and reactive oxygen species were increased by PM_2.5 exposure. PM_2.5 also induced a significant increase of the inflammatory cytokines including interleukin (IL)‐6, IL‐8, IL‐1β and tumor necrosis factor α. Meanwhile, PM_2.5 triggered autophagy formation and alteration of the nuclear factor erythroid‐2‐related factor 2 pathway. Furthermore, human bronchial epithelial cells were co‐treated with PM_2.5 and resveratrol in the presence or absence of 3‐methylamphetamine, an inhibitor of autophagic formation. It was revealed that resveratrol intervention abolished PM_2.5‐induced oxidative injury partially through the suppression of autophagy deregulation. Findings from this study could provide new insights into the molecular mechanisms of pulmonary intervention during PM_2.5 exposure.     

阿魏酸对大气细颗粒物PM2.5诱导的小鼠主动脉炎症的干预作用

目的 探讨大气细颗粒物PM2.5对小鼠主动脉Toll样受体（Toll-like receptors,TLRs）信号通路的影响及阿魏酸的干预作用。方法 采用气管滴注方法以10,20 mg·kg^-1的PM2.5处理小鼠,并用40,80 mg·kg^-1的阿魏酸对部分20 mg·kg^-1 PM2.5处理后的小鼠进行治疗。2周后处死小鼠,血液细胞分析仪检测小鼠血液中炎症细胞水平,ELISA检测血清中IL-1β和IL-6的含量,并用荧光定量PCR检测主动脉中IL-1β和IL-6的mRNA水平,Western blot检测各组小鼠主动脉组织中TLR2、TLR4、MyD88、NF-κB p65蛋白的表达,免疫组化技术观察TLR2和TLR4在小鼠主动脉中的水平。结果 PM2.5能提高血液中NEUT、EOS的数量及其在总细胞中的比率,增加血液和主动脉组织中炎症因子IL-1β、IL-6的含量,上调主动脉组织中的TLRs通路相关分子TLR2、TLR4、MyD88、NF-κB p65的表达;而用阿魏酸干预后,血液中白细胞数量、EOS数量、NEUT与EOS的比率明显降低,IL-1β、IL-6水平下降。同时主动脉组织中的TLRs通路相关分子的表达下调。结论 PM2.5可能通过TLRs通路诱导小鼠主动脉炎症的产生,而阿魏酸可能通过抑制TLRs通路相关因子的表达而发挥抑制PM2.5诱导的小鼠主动脉炎症的作用。     

MiR‐146a regulates PM1‐induced inflammation via NF‐κB signaling pathway in BEAS‐2B cells

Exposure to particulate matter (PM) leads to kinds of cardiopulmonary diseases, such as asthma, COPD, arrhythmias, lung cancer, etc., which are related to PM‐induced inflammation. We have found that PM_2.5 (aerodynamics diameter <2.5 µm) exposure induces inflammatory response both in vivo and in vitro. Since the toxicity of PM is tightly associated with its size and components, PM₁ (aerodynamics diameter <1.0 µm) is supposed to be more toxic than PM_2.5. However, the mechanism of PM₁‐induced inflammation is not clear. Recently, emerging evidences prove that microRNAs play a vital role in regulating inflammation. Therefore, we studied the regulation of miR‐146a in PM₁‐induced inflammation in human lung bronchial epithelial BEAS‐2B cells. The results show that PM₁ induces the increase of IL‐6 and IL‐8 in BEAS‐2B cells and up‐regulates the miR‐146a expression by activating NF‐κB signaling pathway. Overexpressed miR‐146a prevents the nuclear translocation of p65 through inhibiting the IRAK1/TRAF6 expression, and downregulates the expression of IL‐6 and IL‐8. Taken together, these results demonstrate that miR‐146a can negatively feedback regulate PM₁‐induced inflammation via NF‐κB signaling pathway in BEAS‐2B cells.