Prenatal ozone exposure abolishes stress activation of Fos and tyrosine hydroxylase in the nucleus tractus solitarius of adult rat

Ozone (O₃) is widely distributed in the environment, with high levels of air pollution. However, very few studies have documented the effects on postnatal development of O₃ during pregnancy. The long-term effects of prenatal O₃ exposure in rats (0.5 ppm 12 h/day from embryonic day E5 to E20) were evaluated in the adult nucleus tractus solitarius (NTS) regulating respiratory control. Neuronal response was assessed by Fos protein immunolabeling (Fos-IR), and catecholaminergic neuron involvement by tyrosine hydroxylase (TH) labeling (TH-IR). Adult offspring were analyzed at baseline and following immobilization stress (one hour, plus two hours’ recovery); immunolabeling was observed by confocal microscopy. Prenatal O₃ increased the baseline TH gray level per cell (p < 0.001). In contrast, the number of Fos-IR cells, Fos-IR/TH-IR colabeled cells and proportion of TH double-labeled with Fos remained unchanged. After stress, the TH gray level (p < 0.001), number of Fos-IR cells (p < 0.001) and of colabeled Fos-IR/TH-IR cells (p < 0.05) and percentage of colabeled Fos-IR/TH-IR neurons against TH-IR cells (p < 0.05) increased in the control group. In prenatal-O₃ rats, immobilization stress abolished these increases and reduced the TH gray level (p < 0.05), indicating that prenatal O₃ led to loss of adult NTS reactivity to stress. We conclude that long-lasting sequelae were detected in the offspring beyond the prenatal O₃ exposure. Prenatal O₃ left a print on the NTS, revealed by stress. Disruption of neuronal plasticity to new challenge might be suggested.     

Measurement of dyspnea: word labeled visual analog scale vs. verbal ordinal scale

We previously used a verbal ordinal rating scale to measure dyspnea. That scale was easy for subjects to use and the words provided consistency in ratings. We have recently developed a word labeled visual analog scale (LVAS) with labels placed by the subjects, retaining the advantages of a verbal scale while offering a continuous scale that generates parametric data. In a retrospective meta-analysis of data from 43 subjects, individuals differed little in their placement of words on the 100 mm LVAS (mean+/-S.D. for slight=20+/-2.5 mm, moderate=50+/-5 mm and severe=80+/-6 mm) and ratings were distributed uniformly along the scale. A significant stimulus-response correlation was obtained for both the LVAS (r(2)=0.98) and for the verbal ordinal scale (Spearman r=0.94). The resolution of the two scales differed only slightly. With meaningful verbal anchors, well-defined end-points, and clear instructions about the specific sensation to be rated, both scales provide valid measures of dyspnea.     

颗粒物PM10和CD4+T淋巴细胞IL-4 DNA甲基化在儿童变应性鼻炎发病机制中的研究

目的　探讨大气污染PM10对变应性鼻炎儿童CD4+T淋巴细胞IL-4基因启动子区域甲基化的表观遗传调控及相关转录水平表达的影响。方法　选择2012年上海儿童医学中心耳鼻咽喉科就诊的35例6～12岁变应性鼻炎患儿随访1年,收集血样及设立匹配对照组（30例）,进行IL-4基因启动子区域甲基化克隆测序及mRNA表达水平检测。评估PM2.5和PM10的个人综合暴露。结果　变应性鼻炎组CD4+T淋巴细胞中IL-4基因启动子区域平均甲基化程度低于对照组（P =0.038）;其中-48、+54甲基化程度有差异（P =0.041、0.032）;变应性鼻炎组IL-4转录水平升高（P =0.039）,与其平均DNA甲基化水平呈负相关（r =-0.452,P =0.032）。转录水平与对照组无显著性差异。校正后,变应性鼻炎儿童PM10暴露与其IL-4基因启动子区域甲基化程度呈负相关（r 2=0.419,β=-0.470,SD =0.781,P =0.045）。结论　变应性鼻炎儿童IL-4基因启动子区域低甲基化水平可能受到PM10影响。     

Characterization of Polydimethylsiloxane (PDMS) Properties for Biomedical Micro/Nanosystems

Polydimethylsiloxane (PDMS Sylgard 184, Dow Corning Corporation) pre-polymer was combined with increasing amounts of cross-linker (5.7, 10.0, 14.3, 21.4, and 42.9 wt.%) and designated PDMS1, PDMS2, PDMS3, PDMS4, and PDMS5, respectively. These materials were processed by spin coating and subjected to common micro-fabrication, micro-machining, and biomedical processes: chemical immersion, oxygen plasma treatment, sterilization, and exposure to tissue culture media. The PDMS formulations were analyzed by gravimetry, goniometry, tensile testing, nano-indentation, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Spin coating of PDMS was formulation dependent with film thickness ranging from 308 microm on PDMS1 to 171 microm on PDMS5 at 200 revolutions per minute (rpm). Ultimate tensile stress (UTS) increased from 3.9 MPa (PDMS1) to 10.8 MPa (PDMS3), and then decreased down to 4.0 MPa (PDMS5). Autoclave sterilization (AS) increased the storage modulus (sigma) and UTS in all formulations, with the highest increase in UTS exhibited by PDMS5 (218%). PDMS surface hydrophilicity and micro-textures were generally unaffected when exposed to the different chemicals, except for micro-texture changes after immersion in potassium hydroxide and buffered hydrofluoric, nitric, sulfuric, and hydrofluoric acids; and minimal changes in contact angle after immersion in hexane, hydrochloric acid, photoresist developer, and toluene. Oxygen plasma treatment decreased the contact angle of PDMS2 from 109 degrees to 60 degrees. Exposure to tissue culture media resulted in increased PDMS surface element concentrations of nitrogen and oxygen.     

Fat-free mass hydration in newborns: assessment and implications for body composition studies

Aim: Equipment (Pea Pod) offering new possibilities to assess infant body composition has recently become available and has already been used in several studies. In the Pea Pod, body density is converted to body composition using one of two models (‘Fomon’ or ‘Butte’) with different water content in fat‐free mass (hydration factor, HF). In healthy full‐term infants, we assessed HF and its biological variability in 12 newborns and calculated body composition using the two models at 1 and 12 weeks in 108 infants. Body weight and volume were assessed in Pea Pod, and body water was assessed using isotope dilution. Results: Hydration factor was 80.9% with low biological variability (0.8% of average HF). Body fat (%) was significantly lower at 1 and 12 weeks when calculated using the ‘Butte’ model than when using the ‘Fomon’ model. The difference was more pronounced at one than at 12 weeks. Conclusion: Our HF value agrees with that in the ‘Fomon’ model, its low biological variability can be reconciled with the statement that Pea Pod is accurate in newborns and ‘Fomon’ is the best available model for studies in Pea Pod.     

抗菌处理对猪肺动脉瓣膜细胞活性及组织结构的影响

目的 探讨抗菌处理对肺动脉瓣膜细胞活性和组织结构的影响因素及优化同种瓣膜的制备方法。方法 3组猪肺动脉瓣叶(n=6)浸泡在含抗生素的DMEM液中，在不同温度下孵育6h或24h。然后通过XTT比色法测定瓣膜细胞活性，用免疫组织化学荧光染色检测瓣膜细胞和细胞外基质，并行光镜观察。结果 抗菌时间为24h，37℃抗菌组与4℃抗菌组的瓣膜细胞活性与瓣膜组织结构无明显区别。抗菌6h组的瓣膜细胞活性与瓣膜组织结构明显优于抗菌24h组。结论 抗菌时间为24h时，抗菌温度对瓣膜细胞活性及结构完整性无明显影响。抗菌时间缩短至6h，有利于瓣膜细胞活性与结构完整性的保持。     

新生隐球菌墨汁染色检查实验的改进

目的为消除生物安全隐患,让学生能安全高效地完成新生隐球菌墨汁染色检查实验。方法分别用10％EP醛或56℃水浴5rain对腹腔液、脑脊液中的新生隐球菌进行灭活处理,使其不再具有活性和致病性,镜下观察其形态的改变。结果用10％甲醛处理过的新生隐球菌,其荚膜形态已不能观察,而经56℃水浴灭活的新生隐球菌,其荚膜形态没有发生变化。结论新生隐球菌腹腔液或脑脊液采用56℃水浴5min即可灭活而不影响其荚膜形态,为学生安全高效地完成新生隐球菌墨汁染色检查实验提供了条件。     

Genetic and epigenetic influence on the response to environmental particulate matter

Ambient air pollution, including particulate matter (PM) and gaseous pollutants, represents important environmental exposures that adversely affect human health. Because of their heritable and reversible nature, epigenetic modifications provide a plausible link between the environment and alterations in gene expression that might lead to disease. Epidemiologic evidence supports that environmental exposures in childhood affect susceptibility to disease later in life, supporting the belief that epigenetic changes can affect ongoing development and promote disease long after the environmental exposure has ceased. Indeed, allergic disorders often have their roots in early childhood, and early exposure to PM has been strongly associated with the subsequent development of asthma. The purpose of this review is to summarize recent findings on the genetic and epigenetic regulation of responses to ambient air pollutants, specifically respirable PM, and their association with the development of allergic disorders. Understanding these epigenetic biomarkers and how they integrate with genetic influences to translate the biologic effect of particulate exposure is critical to developing novel preventative and therapeutic strategies for allergic disorders.     

Roles of pollution in the prevalence and exacerbations of allergic diseases in Asia

The prevalence of asthma and allergic diseases has been found to be increasingly rapidly, especially in developing countries. Environmental factors have been found to be important contributors to the manifestations of allergic diseases. Air pollution has been extensively studied in different regions of the world. The levels of ambient air pollutants in many Asian countries are very high when compared with those in developed Western countries. However, the prevalence of asthma was relatively low across many Asian countries. Many studies have clearly documented that environmental air pollution is an important factor resulting in exacerbations of asthma. In particular, levels of traffic-related pollutants are increasing rapidly across many Asian countries in parallel with the level of urbanization and economic development. The loss of protective factors associated with a rural environment will further contribute to the adverse effect on patients with allergic diseases such as asthma. In this review the roles of air pollution were examined in relation to the inception and exacerbations of allergic diseases in Asia.