慢性乙型肝炎患者外周血淋巴细胞穿孔素的表达

目的：了解慢性乙型肝炎患者外周血淋巴细胞（PBL）穿孔素（PFP）的表达情况及其与疾病的关系。方法：用抗人PFP单克隆抗体，采用免疫组化染色法，观察慢性乙型肝炎患者PBL中总的PFP阳性细胞的百分率，结果：慢性乙型肝炎PBL中PFP表达与正常对照组之间存在明显差异，结论：乙型肝炎病毒感染慢性化与机体PBL中PFP的表达水平低下密切相关。     

壬基酚对体外培养大鼠胚胎发育的毒性研究

目的 研究4-壬基酚(4-NP)在体外条件下对大鼠胚胎生长发育的影响，探讨其胚胎毒性作用机制。方法 采用植入后全胚胎培养模型，将9.5d Wistar大鼠胚胎与含4-NP的大鼠即刻离心血清共培养48h(4-NP终浓度为0，6.25，12.5，25，50，100mg/L)，观察4-NP对大鼠胚胎生长发育和组织器官形态分化的影响，并用光镜、电镜检测胚胎和卵黄囊的组织结构。结果 4-NP在25mg/L以上可诱发卵黄囊生长和血管分化不良、胚胎生长迟缓及器官形态分化异常，严重者出现神经系统、心脏、腮弓发育异常及小肢芽、体位异常等畸形；100mg/L的4-NP对体外培养胚胎主要呈致死效应。光镜可见实验组胚胎多个器官组织出现病理改变，光镜和电镜下可见卵黄囊3层结构受损，以上结果均呈明显的剂量-反应关系。结论 4-NP对体外培养的大鼠胚胎具有-定的胚胎毒性。其胚胎毒性机制可能与4-NP对卵黄囊胎盘的结构和功能的破坏及其直接的细胞毒性有关。     

剖宫产术前访视术后支持的临床研究

目的:探讨术前访视术后支持心理干预在缓解围术期应激反应的作用及对术后恢复的影响。方法:术前手术室护士到床前与产妇交流,自我介绍并交待术前注意事项,术前术后进行矫正认知及松弛训练。结果:通过术前访视的产妇围术期的血压、心率较对照组明显稳定,术后疼痛心理评分6h后明显低于对照组,术后肠蠕动恢复及下地时间方面较对照组明显提前。结论:剖宫产术前访视能减轻产妇围术期应激反应,并能促进产妇术后早日恢复。     

Age as a Critical Determinant of Atrial Fibrillation: A Two-sided Relationship

The incidence of atrial fibrillation (AF), the most common sustained arrhythmia and a major public health burden, increases exponentially with age. However, mechanisms underlying this long-recognized association remain incompletely understood. Experimental and human studies have demonstrated the involvement of aging in several arrhythmogenic processes, including atrial electrical and structural remodelling, disturbed calcium homeostasis, and enhanced atrial ectopic activity/increased vulnerability to re-entry induction. Given this wide range of putative mechanisms, the task of delineating the specific effects of aging responsible for AF promotion is not simple, as aging is itself associated with increasing prevalence of a host of AF-predisposing conditions, including heart failure, coronary artery disease, and hypertension. Although we usually think of old age promoting AF, there is also evidence that young age may actually have a protective effect against AF occurrence. For example, the low AF incidence among populations of young patients with significant structural congenital heart disease and substantial atrial enlargement/remodelling suggests that younger age might protect against fibrillation in the diseased atrium; efforts at understating how younger age may prevent AF might be helpful in elucidating missing mechanistic links between AF and age. The goal of this paper is to review the epidemiologic and pathophysiologic evidence regarding mechanisms underlying age-related AF. Although the therapeutic options for AF have recently improved, major gaps still remain and a better understanding of the special relationship between age and AF may be important for the identification of new targets for therapeutic innovation.     

La respuesta sistémica Th17/IL-17A aparece antes del proceso neurodegenerativo en el hipocampo de ratas expuestas a bajas dosis de ozono

IntroductionExposure to low doses of O₃ leads to a state of oxidative stress. Some studies show that oxidative stress can modulate both the CNS and systemic inflammation, which are important factors in the development of Alzheimer disease (AD).ObjectiveThis study aims to evaluate changes in the frequency of Th17-like cells (CD3⁺CD4⁺IL-17A⁺), the concentration of IL-17A in peripheral blood, and hippocampal immunoreactivity to IL-17A in rats exposed to low doses of O₃.MethodsOne hundred eight male Wistar rats were randomly assigned to 6 groups (n = 18) receiving the following treatments: control (O₃ free) or O₃ exposure (0.25 ppm, 4 hours daily) over 7, 15, 30, 60, and 90 days. Twelve animals from each group were decapitated and a peripheral blood sample was taken to isolate plasma and mononuclear cells. Plasma IL-17A was quantified using LUMINEX, while Th17-like cells were counted using flow cytometry. The remaining 6 rats were deeply anaesthetised and underwent transcardial perfusion for immunohistological study of the hippocampus.ResultsResults show that exposure to O₃ over 7 days resulted in a significant increase in the frequency of Th17-like cells and levels of IL-17A in peripheral blood. However, levels of Th17/IL-17A in peripheral blood were lower at day 15 of exposure. We also observed increased IL-17A in the hippocampus beginning at 30 days of exposure.ConclusionThese results indicate that O₃ induces a short-term, systemic Th17-like/IL-17A effect and an increase of IL-17A in the hippocampal tissue during the chronic neurodegenerative process.     

Safety assessment for octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate (CAS Reg. No. 2082-79-3) from use in food contact applications

Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (CAS Reg. No. 2082-79-3), currently marketed as Irganox 1076 (I-76), is a sterically hindered phenolic antioxidant used in a variety of organic substrates, including those used in the manufacture of food contact articles. In 2012, the US Food and Drug Administration (USFDA), Office of Food Additive Safety (OFAS), initiated a post-market re-evaluation of the food contact applications of I-76. This project aimed to ensure that current dietary exposures from the use of I-76 in food contact articles are accurately captured and the safety assessment considered all relevant and available toxicological information. To accomplish these aims, the USFDA reviewed the available toxicological studies and chemistry information on food contact applications of I-76. Based on this in-depth analysis, a NOAEL of 64 mg/kg-bw/d (female rats) from a chronic rat study and a cumulative estimated dietary intake (CEDI) of 4.5 mg/p/d, was used to calculate a margin of exposure (MOE) of ∼850. We concluded that the previous and current exposure levels provide an adequate margin of safety (MOS) and remain protective of human health for the regulated uses.     

静态张应力作用下人牙周膜干细胞核心结合因子Cbfa1表达的变化

目的检测静态张应力作用对人牙周膜干细胞核心结合因子Cbfa1表达变化的影响。方法有限稀释法克隆化培养纯化人牙周膜干细胞(hPDLSCs),应用内外双层套筒式硅胶膜细胞加力装置对人牙周膜干细胞加力,加力时间点为0、3、6、12、24小时。采用原位杂交和实时定量PCR检测各加力时间点Cbfa1 mRNA的表达;蛋白免疫印迹法(Western blot)检测人牙周膜干细胞受力后Cbfa1蛋白的表达。结果人牙周膜干细胞受到静态张应力作用后3小时、6小时、12小时Cbfa1 mRNA表达均升高(P0.05),且以加力3小时最为明显,6小时后开始下降,24小时后基本恢复到不加力时的表达水平。加力3小时Cbfa1蛋白表达未见明显升高,加力6小时后Cbfa1蛋白逐渐升高,一直持续到加力24小时(P0.05)。结论静态张应力作用下,人牙周膜干细胞核心结合因子Cbfa1在RNA水平和蛋白水平的表达均发生变化,说明Cbfa1在机械力促使人牙周膜干细胞向成骨细胞方向分化的过程中起到了重要作用。