眼表铁过载小鼠干眼模型的构建和机制研究

目的：通过给小鼠腹腔注射右旋糖酐铁，建立小鼠铁过载干眼模型并初步探索其可能的机制。

方法：将40只雄性C57BL/6小鼠(取右眼为实验眼)用随机数字表法将小鼠分为4组：对照组10只，每次腹腔注射生理盐水0.2mL； 低剂量组、中剂量组、高剂量组各10只为模型组，每次分别腹腔注射浓度为12.5、25、50mg/mL的右旋糖酐铁溶液0.2mL。每3d注射1次，共注射28d。注药后第7、14、28d观察各组小鼠眼表炎症指数、角膜荧光素染色、泪膜破裂时间(BUT)及泪液分泌量(SⅠt)，评估干眼及眼表炎症程度。28d后处死小鼠，取角膜、结膜及泪腺组织，进行HE染色、普鲁士蓝染色以及组织铁检测，评估小鼠炎症反应及铁过载情况； 采用酶联免疫吸附试验(ELISA)检测炎症因子白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)、基质金属蛋白酶-9(MMP-9)的表达情况。

结果：与对照组相比，模型组小鼠出现一系列干眼症状，小鼠眼表炎症指数增高，角膜荧光素染色评分增加，BUT缩短，泪液分泌量减少(均P<0.05)； 模型组小鼠角膜、结膜及泪腺组织均受到不同程度的损伤，各组织眼表铁沉积情况较对照组加重，组织铁含量明显增加(均P<0.01)； 模型组小鼠角膜、结膜及泪腺组织中炎症因子(IL-1β、TNF-α、MMP-9)的含量均高于对照组(均P<0.01)，随着右旋糖酐铁注药时间及浓度增加，小鼠干眼及眼表炎症程度逐渐加重。

结论：腹腔注射右旋糖酐铁可成功建立小鼠铁过载干眼模型，其机制可能与铁过载加重眼表炎症反应有关。     

深圳市龙岗区大气污染物与医院呼吸系统疾病门诊量的广义相加模型分析

目的 探讨深圳市龙岗区主要大气污染物(SO₂、NO₂、PM₁₀与PM_2.5)与医院呼吸系统疾病门诊量的关系。 方法 收集2013年1月1日－2015年12月31日深圳市龙岗区2家公立医院呼吸系统疾病逐日门诊量资料,深圳市龙岗区逐日大气污染物浓度及逐日气象资料分别来自深圳市环境监测站及气象局,运用时间序列分析广义相加模型对大气污染物日均浓度与呼吸系统疾病门诊量的关系及滞后效应进行分析。 结果 深圳市龙岗区2013－2015年SO₂ 、NO₂ 、PM₁₀ 与PM_2.5浓度中位数分别为8.08、38.08、46.05 μg/m³及31.04 μg/m³。2家医院三年呼吸系统门诊总量为549 169人次,日门诊量中位数为499人次/d。广义相加模型分析结果表明,除NO₂对呼吸系统疾病门诊量影响差异无统计学意义外,其余三种污染物对呼吸系统疾病门诊量影响均存在滞后效应,污染物每升高10 μg/m³,滞后2 d时SO₂对门诊量影响最强(相对危险度RR为1.030 7,95%CI:1.015 7~1.045 9),滞后3 d时PM₁₀与PM_2.5浓度对呼吸系统疾病门诊量影响最强(PM₁₀:RR=1.005 4,95%CI:1.002 8~1.008 0,PM_2.5:RR=1.006 0, 95%CI:1.002 7~1.009 4)。 结论 深圳市龙岗区大气SO₂、PM₁₀与PM_2.5浓度对医院呼吸系统疾病门诊量影响存在滞后效应。     

Tuberculosis and other chronic morbidity profile of sewage workers of Delhi

Background

Sewage management is hazardous due to chronic exposure to chemical gases, bioaerosols and micro-organisms through inhalation; accidental oral intake and penetration through skin or mucous membranes through injuries or breech in personal protective equipment. While there has been some research on isolated infections and multisystem symptom profiling of sewage workers, there is little research on the burden of chronic illnesses like Tuberculosis and Non Communicable Diseases (NCDs).

Establishment of an Evaluation Method for Gene Silencing by Serial Pulmonary Administration of siRNA and pDNA Powders: Naked siRNA Inhalation Powder Suppresses Luciferase Gene Expression in the Lung

In order to evaluate the in vivo effect of inhaled formulations, it is a gold standard to create a lung metastasis model by intravenously injecting cancer cells into an animal. Because the cancer grows from the blood vessel side, there is a possibility of underestimating the effect of an inhaled formulation administered to the lung epithelium side. In addition, the metastasis model has disadvantages in terms of preparation time and expense. The present study aimed to establish a new method to evaluate the effect of an inhaled small interfering RNA (siRNA) formulation that is more correct, more rapid, and less expensive. We investigated whether siRNA can suppress gene expression of plasmid DNA (pDNA) by serial pulmonary administration of siRNA and pDNA powders prepared by spray-freeze-drying. We revealed that formulations of dry siRNA powder significantly suppressed gene expression of pDNA powder compared with a control group with no siRNA. Naked siRNA inhalation powder with no vector showed the suppression of gene expression equivalent to that of an siRNA-polyethyleneimine complex without damaging tissues. These results show that the present method is suitable for evaluating the gene-silencing effect of inhaled siRNA powders.     

The Relationship Between Air Pollution and Lung Cancer in Nonsmokers in Taiwan

Introduction

For never-smokers (smoked <100 lifetime cigarettes), lung cancer (LC) has emerged as an important issue. We aimed to investigate the effects of prevalence changes in tobacco smoking and particulate matter (PM) 2.5 (PM_2.5) levels on LC in Taiwan, in relation to contrasting PM_2.5 levels, between Northern Taiwan (NT) and Southern Taiwan (ST).

Massive air embolism resulting in ischemic stroke after left ventricular assist device implantation

We present the first case of ischemic stroke secondary to massive air embolus during implantation of a left ventricular assist device (LVAD). The patient experienced a suction event at the time of aortic cannula removal. Despite the use of all standard deairing techniques and flooding the operative field with continuous‐flow carbon dioxide, a significant amount of air was delivered into the ascending aorta through the LVAD pump.     

Peat smoke inhalation alters blood pressure,baroreflex sensitivity,and cardiac arrhythmia risk in rats

ABSTRACT

Wildland fires (WF) are linked to adverse health impacts related to poor air quality. The cardiovascular impacts of emissions from specific biomass sources are however unknown. The purpose of this study was to assess the cardiovascular impacts of a single exposure to peat smoke, a key regional WF air pollution source, and relate these to baroreceptor sensitivity and inflammation. Three-month-old male Wistar-Kyoto rats, implanted with radiotelemeters for continuous monitoring of heart rate (HR), blood pressure (BP), and spontaneous baroreflex sensitivity (BRS), were exposed once, for 1-hr, to filtered air or low (0.38 mg/m³ PM) or high (4.04 mg/m³) concentrations of peat smoke. Systemic markers of inflammation and sensitivity to aconitine-induced cardiac arrhythmias, a measure of latent myocardial vulnerability, were assessed in separate cohorts of rats 24 hr after exposure. PM size (low peat = 0.4–0.5 microns vs. high peat = 0.8–1.2 microns) and proportion of organic carbon (low peat = 77% vs. high peat = 65%) varied with exposure level. Exposure to high peat and to a lesser extent low peat increased systolic and diastolic BP relative to filtered air. In contrast, only exposure to low peat elevated BRS and aconitine-induced arrhythmogenesis relative to filtered air and increased circulating levels of low-density lipoprotein cholesterol, complement components C3 and C4, angiotensin-converting enzyme (ACE), and white blood cells. Taken together, exposure to peat smoke produced overt and latent cardiovascular consequences that were likely influenced by physicochemical characteristics of the smoke and associated adaptive homeostatic mechanisms.