In vivo epigenetic effects induced by engineered nanomaterials: A case study of copper oxide and laser printer-emitted engineered nanoparticles

Evidence continues to grow on potential environmental health hazards associated with engineered nanomaterials (ENMs). While the geno- and cytotoxic effects of ENMs have been investigated, their potential to target the epigenome remains largely unknown. The aim of this study is two-fold: 1) determining whether or not industry relevant ENMs can affect the epigenome in vivo and 2) validating a recently developed in vitro epigenetic screening platform for inhaled ENMs. Laser printer-emitted engineered nanoparticles (PEPs) released from nano-enabled toners during consumer use and copper oxide (CuO) were chosen since these particles induced significant epigenetic changes in a recent in vitro companion study. In this study, the epigenetic alterations in lung tissue, alveolar macrophages and peripheral blood from intratracheally instilled mice were evaluated. The methylation of global DNA and transposable elements (TEs), the expression of the DNA methylation machinery and TEs, in addition to general toxicological effects in the lung were assessed. CuO exhibited higher cell-damaging potential to the lung, while PEPs showed a greater ability to target the epigenome. Alterations in the methylation status of global DNA and TEs, and expression of TEs and DNA machinery in mouse lung were observed after exposure to CuO and PEPs. Additionally, epigenetic changes were detected in the peripheral blood after PEPs exposure. Altogether, CuO and PEPs can induce epigenetic alterations in a mouse experimental model, which in turn confirms that the recently developed in vitro epigenetic platform using macrophage and epithelial cell lines can be successfully utilized in the epigenetic screening of ENMs.     

Reading the unique DNA methylation landscape of the brain: Non-CpG methylation,hydroxymethylation, and MeCP2

DNA methylation at CpG dinucleotides is an important epigenetic regulator common to virtually all mammalian cell types, but recent evidence indicates that during early postnatal development neuronal genomes also accumulate uniquely high levels of two alternative forms of methylation, non-CpG methylation and hydroxymethylation. Here we discuss the distinct landscape of DNA methylation in neurons, how it is established, and how it might affect the binding and function of protein readers of DNA methylation. We review studies of one critical reader of DNA methylation in the brain, the Rett syndrome protein methyl CpG-binding protein 2 (MeCP2), and discuss how differential binding affinity of MeCP2 for non-CpG and hydroxymethylation may affect the function of this methyl-binding protein in the nervous system.     

Dynamic LVOT Obstruction and Aortic Stenosis in the Same Patient: A Case of Challenging Doppler Hemodynamics

We present a patient with both dynamic left ventricular outflow tract obstruction and valvular aortic stenosis. The aortic valve was calcified, and velocities and gradients measured by continuous‐wave Doppler met standard criteria for severe aortic stenosis. The increased subvalvular velocities invalidated assumptions of the simplified Bernoulli equation; correction using the longer form of the Bernoulli equation suggested a lower but still significant gradient. The complex shape of the subvalvular spectral Doppler envelope indicated supranormal systolic function and dynamic left ventricular outflow obstruction. Left heart catheterization with an end‐hole catheter was required to determine the subvalvular and valvular components of the obstruction.     

妇科腹腔镜围手术期碳水化合物口服疗法对术后胰岛素抵抗影响的研究

目的观察妇科腹腔镜手术围术期碳水化合物口服疗法和传统禁饮食方案两种不同的临床处理措施对于术后胰岛素抵抗（IR）的影响。 方法选取2018年2月至8月入住徐州医科大学附属医院妇科，行腹腔镜下全子宫切除手术的非糖尿病患者共98例，将采用围术期碳水化合物口服疗法者作为观察组（50例），采用传统禁饮食方案者作为对照组（48例）。检测所有病例的术前、术后第1天及第3天的空腹血糖（FPG）及空腹胰岛素（FINS），并利用稳态模式评估法计算稳态模型胰岛素抵抗指数（HOME-IR）。对于观察组与对照组患者术前、术后第1天和术后第3天的FPG、FINS和HOME-IR等指标，组间比较采用独立样本t检验。两组患者术后腹胀、术后24 h通气、术后发热的发生情况的比较采用确切概率法检验。 结果观察组与对照组比较，术前和术后第1天FPG差异无统计学意义（P均>0.05），术后第3天FPG明显降低［（4.34±0.59）mmol/L vs （4.96±0.64）mmol/L］，差异有统计学意义（t=-4.96，P=0.002）。观察组与对照组比较，术前和术后第1天FINS差异无统计学意义（P均>0.05），术后第3天FINS明显降低［（45.39±13.55）mIU/L vs （51.18±9.34） mIU/L］，差异有统计学意义（t=-2.46，P=0.033）。观察组与对照组比较，术前HOME-IR差异无统计学意义（P>0.05），术后第1天和术后第3天HOME-IR明显降低［（13.08±4.80）vs （15.03±4.11）；（9.37±3.65）vs （11.30±2.55）］，差异有统计学意义（t=-0.69，P=0.042；t=-3.99，P=0.033）。两组患者术后其他观察指标比较，观察组术后24 h通气率与对照组比较明显增高（76.0% vs 64.6%），差异有统计学意义（P=0.045）。两组患者在术后腹胀、术后发热的发生率方面差异无统计学意义（P均>0.05）。两组患者均未发生术中误吸。 结论妇科腹腔镜手术围术期应用碳水化合物口服疗法较传统禁饮食方案，能有效减轻术后IR程度，促进术后康复进程，且不增加围术期并发症的发生率。