姜黄素促进高糖环境下骨髓间充质干细胞成骨分化的作用及机制研究

目的研究姜黄素对高糖环境下骨髓间充质干细胞(BMSCs)成骨分化的影响及可能机制。方法原代分离培养大鼠骨髓间充质干细胞,分为正常组、高糖组和高糖+姜黄素组。CCK-8检测细胞增殖;免疫荧光染色检测细胞NF-κB p65核转位; Western blot检测NF-κB p65核蛋白表达。成骨能力检测分为正常糖浓度成骨诱导组、高糖浓度成骨诱导组、高糖+姜黄素成骨诱导组,其中成骨诱导培养为每100 m Lα-MEM培养基中加入2 mmol/L谷氨酰胺、10 mmol/Lβ-甘油磷酸钠、10 nmol/L地塞米松、50 mg/L抗坏血酸。茜素红染色检测细胞钙结节形成,荧光定量PCR检测成骨相关基因Runx2和OCN mRNA表达。结果接种培养7 d,倒置显微镜下可见骨髓间充质干细胞集落,呈克隆性生长;传代培养以后细胞伸展为长梭形。CCK-8结果表明,与正常组比较,高糖组细胞1 d、3 d时增殖能力无显著性差异(P0.05); 5 d时与正常组比较,高糖组细胞增殖能力显著降低(P0.05); 1 d、3 d、5 d时姜黄素组与高糖组比较细胞增殖能力差异均无统计学意义(P0.05)。与正常组比较,高糖组细胞NF-κB p65活化入核增多,姜黄素组则抑制高糖浓度下细胞NF-κB p65核转位,Western blot显示姜黄素可抑制NF-κB p65核蛋白表达。各组细胞成骨诱导14 d后茜素红染色,正常组可见大量矿化结节,高糖组仅见少量矿化结节,而姜黄素处理可以明显促进高糖浓度下钙结节形成。PCR结果显示,各组细胞成骨诱导14 d后,与正常组比较,高糖组成骨分化相关基因Runx2、OCN mRNA表达显著降低,差异有统计学意义(P0.05);高糖+姜黄素组则可以促进高糖环境下骨髓间充质干细胞成骨分化相关基因Runx2、OCN mRNA表达,差异有统计学意义(P0.05)。结论姜黄素能促进高糖环境下骨髓间充质干细胞成骨分化,其机制可能与抑制高糖浓度下细胞NF-κB p65活化相关。     

口服蛋氨酸饲料致大鼠心室重塑的研究

目的:探讨口服蛋氨酸饲料致大鼠心力衰竭模型的机制，及程序性死亡因子4（PDCD4）通路在此过程中的作用。方法:5周龄健康Wistar雄性大鼠30只，适应性喂养1周后，随机分为实验组与对照组，实验组给予3%蛋氨酸饲料喂养，对照组标准饲料喂养。12周后进行血流动力学检测，采用酶联免疫法测定血清同型半胱氨酸（HCY）及N端前脑钠肽（NT-proBNP）水平，心脏彩超进行心功能评估，病理染色明确有无细胞肥大、纤维化，Western blot检测心肌组织中PDCD4蛋白的表达。结果:3%蛋氨酸饲料喂养组HCY水平较对照组升高（均P＜0.05）,心脏彩超提示3%蛋氨酸饲料喂养组大鼠左室射血分数、缩短分数、室间隔厚度显著减低（均P＜0.05），左室收缩末内径及舒张末内径较对照组显著增加（均P＜0.05），Western blot结果显示, PDCD4蛋白表达降低（P＜0.05）。结论:通过口服蛋氨酸饲料造成大鼠高HCY血症可导致大鼠出现心室重塑，并造成心功能受损，其机制可能与PDCD4信号通路的下调有关。     

Skin temperature and vascular attributes as early warning signs of pressure injury

ObjectivesThis study aimed to validate the skin temperature on sacral region and vascular attributes as early warning signs of pressure injury.MethodsTotally 415 patients admitted to the adult intensive care unit from August 2018 to April 2019 were prospectively screened. Daily blood pressure and blood glucose affecting vascular attributes and the relative skin temperature of sacral region were measured for 10 consecutive days. Collect the changes of these indicators during the occurrence of pressure injury. The optimal cut-off values of indicators were determined by X-tile analysis. The risk ratios of indicators associated with pressure injury were compared using the Cox proportional hazards regression model.ResultsThere were no obvious interactions among blood pressure, blood glucose and relative skin temperature (P > 0.05). The optimal cutoff value for above indicators was 63.5 mmHg, 9.9 mmol/L and −0.1 °C, respectively. The incidence of pressure injury peaked on the 4th and 5th day after hospitalization when categorizing the patients into low- and high-risk groups according to the cutoff values (P < 0.05). Based on relative skin temperature, patients in the high-risk group were more likely to develop pressure injury (hazard ratio = 6.36, 95% confidence interval = 3.91, 10.36), when compared to the other two indicators of blood pressure and blood glucose.ConclusionStringent skin temperature and vascular attributes measurements were necessary for preventing pressure injury. Nursing measures should be taken according to warning sings to reduce the incidence of pressure injury.     

高效液相色谱-荧光检测法测定性早熟女童血浆中双酚A和4-壬基酚的含量

目的：建立高效液相色谱-荧光检测法测定性早熟女童血浆中双酚A和4-壬基酚含量的方法。方法：采用Shim-pack VP-ODS C18色谱柱（150 mm×4.6 mm，5 μm），流动相为乙腈∶水=70∶30，流速1 mL/min，柱温30 ℃，检测激发波长275 nm，发射波长315 nm，外标法定量检测血浆中双酚A和4-壬基酚含量。结果：双酚A和4-壬基酚分别在1.45~5 937.50 ng/mL （r2=0.999 9，n=7），1.53~6 250.00 ng/mL（r2=0.998 8，n=7）范围内线性关系良好；日内、日间RSD均<7.83%，方法回收率均>94.6%。结论：本法简便、快速、灵敏、准确，适用于同时测定性早熟女童血浆中双酚A和4-壬基酚的含量和临床血样常规检测。     

Laboratory Biosafety: Laboratory response checklist for infectious disease outbreaks—preparedness and response considerations for emerging threats

The purpose of the Laboratory Response Checklist for Infectious Disease Outbreaks (the Checklist) is to provide public health laboratories and laboratory networks operating at multiple jurisdictional levels with a useful, adaptable tool to help rapidly identify important outbreak response considerations, particularly when investigating a previously unknown infectious disease threat. The Checklist was developed by the National Microbiology Laboratory of Canada in collaboration with provincial/territorial, national and international laboratory experts, including the Canadian Public Health Laboratory Network, and the Global Health Security Action Group Laboratory Network. While the Checklist was initially designed to reflect lessons learned through National Microbiology Laboratory participation in extended national and international outbreak responses (e.g. Zika virus epidemic [2015–2016], Ebola virus epidemic, West Africa [2014–2016]), the importance of optimizing laboratory response coordination has only been underscored by the ongoing challenges presented by the coronavirus disease 2019 (COVID-19) pandemic response requirements. The Checklist identifies five highly interdependent laboratory response themes, each of which encompasses multiple considerations that may be critical to a coordinated, strategic outbreak response. As such, the comprehensive review of Checklist considerations by responding laboratory organizations may provide a valuable opportunity to quickly detect key response considerations and interdependencies, and mitigate risks with the potential to impact public health action.     

Recellularizing of human acellular dermal matrices imaged by high‐definition optical coherence tomography

High‐definition optical coherence tomography (HD‐OCT) permits real‐time 3D imaging of the impact of selected agents on human skin allografts. The real‐time 3D HD‐OCT assessment of (i) the impact on morphological and cellular characteristics of the processing of human acellular dermal matrices (HADMs) and (ii) repopulation of HADMs in vitro by human fibroblasts and remodelling of the extracellular matrix by these cells. Four different skin decellularization methods, Dispase II/Triton X‐100, Dispase II/SDS (sodium dodecyl sulphate), NaCl/Triton X‐100 and NaCl/SDS, were analysed by HD‐OCT. HD‐OCT features of epidermal removal, dermo‐epidermal junction (DEJ) integrity, cellularity and dermal architecture were correlated with reflectance confocal microscopy (RCM), histopathology and immunohistochemistry. Human adult dermal fibroblasts were in vitro seeded on the NaCl/Triton X‐100 processed HADMs, cultured up to 19 days and evaluated by HD‐OCT in comparison with MTT proliferation test and histology. Epidermis was effectively removed by all treatments. DEJ was best preserved after NaCl/Triton X‐100 treatment. Dispase II/SDS treatment seemed to remove all cellular debris in comparison with NaCl/Triton X‐100 but disturbed the DEJ severely. The dermal micro‐architectural structure and vascular spaces of (sub)papillary dermis were best preserved with the NaCl/Triton X‐100. The impact on the 3D structure and vascular holes was detrimental with Dispase II/SDS. Elastic fibre fragmentation was only observed after Dispase II incubation. HD‐OCT showed that NaCl/Triton X‐100 processed matrices permitted in vitro repopulation by human dermal fibroblasts (confirmed by MTT test and histology) and underwent remodelling upon increasing incubation time. Care must be taken in choosing the appropriate processing steps to maintain selected properties of the extracellular matrix in HADMs. Processing HADMs with NaCl/Triton X‐100 permits in vitro the proliferation and remodelling activity of human dermal fibroblasts. HD‐OCT provides unique real‐time and non‐invasive 3D imaging of tissue‐engineered skin constructs and complementary morphological and cytological information.     

气象因素对钉螺密度变化的影响分析

目的 研究自然条件下气象因素对钉螺密度变化的影响,为控制血吸虫病及其钉螺扩散提供科学依据。方法 收集1990－2014年湖北省潜江市春季查螺资料及地面气象观测数据,采用一阶自回归分析方法对实际钉螺密度进行趋势拟合与分解,利用相关分析法对钉螺密度变化率与不同时段、不同气象要素进行相关性分析。结果 对钉螺密度影响最大的气象因子是温度,其次为降水;其中1月平均最低气温和冬季平均最低气温分别是钉螺密度变化率、活螺框变化率影响最大的温度因子;1月平均最低温度升高(或降低)1 ℃,将会导致钉螺密度上升(或下降) 5.080%～6.710%;冬季平均最低温度升高(或降低)1 ℃,活螺框变化率上升(或下降)15.521%～15.928%。降水对钉螺密度影响最大的时段是上年11月至当年4月,该时段内降水偏少20%以上,有利于降低钉螺密度。9－11月日照与钉螺密度变化率、活螺框变化率存在一定相关性。在相关分析基础上分别建立了钉螺密度变化率、活螺框变化率与气象因子的统计回归模型。结论 在12月到来之前清除有螺区杂草有利于降低地表温度和土壤水分含量,能取得一定的灭螺效果。伴随全球气候变化湖北省冬季温度升高趋势明显,可能引发钉螺密度升高。     

Hierarchical non‐negative matrix factorization to characterize brain tumor heterogeneity using multi‐parametric MRI

Tissue characterization in brain tumors and, in particular, in high‐grade gliomas is challenging as a result of the co‐existence of several intra‐tumoral tissue types within the same region and the high spatial heterogeneity. This study presents a method for the detection of the relevant tumor substructures (i.e. viable tumor, necrosis and edema), which could be of added value for the diagnosis, treatment planning and follow‐up of individual patients. Twenty‐four patients with glioma [10 low‐grade gliomas (LGGs), 14 high‐grade gliomas (HGGs)] underwent a multi‐parametric MRI (MP‐MRI) scheme, including conventional MRI (cMRI), perfusion‐weighted imaging (PWI), diffusion kurtosis imaging (DKI) and short‐TE ¹H MRSI. MP‐MRI parameters were derived: T₂, T₁ + contrast, fluid‐attenuated inversion recovery (FLAIR), relative cerebral blood volume (rCBV), mean diffusivity (MD), fractional anisotropy (FA), mean kurtosis (MK) and the principal metabolites lipids (Lip), lactate (Lac), N‐acetyl‐aspartate (NAA), total choline (Cho), etc. Hierarchical non‐negative matrix factorization (hNMF) was applied to the MP‐MRI parameters, providing tissue characterization on a patient‐by‐patient and voxel‐by‐voxel basis. Tissue‐specific patterns were obtained and the spatial distribution of each tissue type was visualized by means of abundance maps. Dice scores were calculated by comparing tissue segmentation derived from hNMF with the manual segmentation by a radiologist. Correlation coefficients were calculated between each pathologic tissue source and the average feature vector within the corresponding tissue region. For the patients with HGG, mean Dice scores of 78%, 85% and 83% were obtained for viable tumor, the tumor core and the complete tumor region. The mean correlation coefficients were 0.91 for tumor, 0.97 for necrosis and 0.96 for edema. For the patients with LGG, a mean Dice score of 85% and mean correlation coefficient of 0.95 were found for the tumor region. hNMF was also applied to reduced MRI datasets, showing the added value of individual MRI modalities. Copyright © 2015 John Wiley & Sons, Ltd.