从兔股骨头中提取总RNA的方法特点

目的:建立一种高效、快速的骨组织总RNA提取方法。方法:实验于2005-01/2006-01在昆明医学院实验动物中心和中国科学院昆明动物研究所中科院细胞与分子进化重点实验室完成。取健康新西兰大白兔1只,截取其股骨头,迅速置于液氮罐中保存,于研钵中研磨,使骨组织始终保存于液氮中,继续研磨,如此重复3次,然后利用Trizol使骨细胞结构迅速破坏,将粉末转入离心管,室温静置5min。随后加入氯仿等有机溶剂处理、离心,使RNA与细胞DNA、蛋白质及其他成分分离从而得到总RNA。最后鉴定RNA的质量、纯度及产率,取2μL提取出的RNA在体积分数为0.008的甲醛变性琼脂糖凝胶上进行电泳,主要观察RNA的28S、18S及5S三个条带是否清晰,有无降解和DNA污染。以99μLDEPC水稀释1μLRNA样品,紫外分光光度计测量其吸光度(A)值,A260/A280之比值表示RNA的纯度,同时根据吸光度值计算其质量浓度。结果:①对提取的兔股骨头RNA进行琼脂糖凝胶电泳,可显示清晰的28S、18S两个条带,5S条带亦可见,表明了RNA是完整的。②用紫外分光光度法测定兔股骨头中提取出的RNAA260/A280,结果表明由本法提取的RNA纯度高,无DNA和蛋白质的污染。③经紫外分光光度计吸收定量,每毫克兔股骨头组织能提取1.0～1.2μg的总RNA。结论:本法提取骨组织总RNA方便、快捷,质量高,可用于骨组织的分子生物学研究。     

缺血预处理程序中心肌环磷酸腺苷含量及环磷酸腺苷依赖蛋白激酶活性的变化

目的:制备大鼠在体缺血再灌注模型,观察缺血预处理程序中心肌环磷酸腺苷含量及环磷酸腺苷依赖蛋白激酶活性的变化。方法:实验于2005-03/2006-10在解放军沈阳军区总医院医学实验动物中心和全军心血管研究所实验室完成。实验分组:选用健康雌性SD大鼠36只,根据预适应程序分为第1,2,3次缺血,第1,2,3次再灌注,每一时间点6只大鼠。实验过程:用手术套管法造成左冠状动脉主干缺血及再灌注。所有实验动物在实验程序结束后,取出心脏迅速置液氮保存备用。实验评估:用放射免疫法测环磷酸腺苷水平,生化法测环磷酸腺苷依赖蛋白激酶活性变化。结果:36只大鼠均进入结果分析。①环磷酸腺苷含量:第1次再灌注组低于第1次缺血组[(0.325±0.015),(0.395±0.024)pmol/g,t=6.06,P<0.001],第2次再灌注组低于第2次缺血组[(0.523±0.017),(0.708±0.067)pmol/g,t=6.56,P<0.001],第3次再灌注组低于第3次缺血组[(0.567±0.031),(0.712±0.038)pmol/g,t=7.24,P<0.001]。②环磷酸腺苷依赖蛋白激酶活性:第1次再灌注组低于第1次缺血组[(10.115±1.000),(16.351±0.849)pkat/g,t=11.12,P<0.001],第2次再灌注组低于第2次缺血组[(11.877±2.213),(14.869±0.619)pkat/g,t=3.31,P<0.01],第3次再灌注组低于第3次缺血组[(11.745±0.987),(14.766±0.329)pkat/g,t=7.09,P<0.001]。③缺血预处理程序中心肌环磷酸腺苷含量及环磷酸腺苷依赖蛋白激酶活性随缺血及再灌注呈周期性波动。在5min缺血预处理时表现为明显增高,而在间隔的再灌注程序中恰呈相反改变,有明显下降的趋势。结论:环磷酸腺苷及环磷酸腺苷依赖蛋白激酶的周期性波动变化可能是激发心肌缺血预处理的机制之一,环磷酸腺苷可能在预处理保护作用中起一些作用。     

Development of the Korean Standardized Antimicrobial Administration Ratio as a Tool for Benchmarking Antimicrobial Use in Each Hospital

BackgroundThe Korea National Antimicrobial Use Analysis System (KONAS), a benchmarking system for antimicrobial use in hospitals, provides Korean Standardized Antimicrobial Administration Ratio (K-SAAR) for benchmarking. This article describes K-SAAR predictive models to enhance the understanding of K-SAAR, an important benchmarking strategy for antimicrobial usage in KONAS.MethodsWe obtained medical insurance claims data for all hospitalized patients aged ≥ 28 days in all secondary and tertiary care hospitals in South Korea (n = 347) from January 2019 to December 2019 from the Health Insurance Review & Assessment Service. Modeling was performed to derive a prediction value for antimicrobial use in each institution, which corresponded to the denominator value for calculating K-SAAR. The prediction values of antimicrobial use were modeled separately for each category, for all inpatients and adult patients (aged ≥ 15 years), using stepwise negative binomial regression.ResultsThe final models for each antimicrobial category were adjusted for different significant risk factors. In the K-SAAR models of all aged patients as well as adult patients, most antimicrobial categories included the number of hospital beds and the number of operations as significant factors, while some antimicrobial categories included mean age for inpatients, hospital type, and the number of patients transferred from other hospitals as significant factors.ConclusionWe developed a model to predict antimicrobial use rates in Korean hospitals, and the model was used as the denominator of the K-SAAR.     

Impact of COVID-19 on Clinicopathological Spectrum of Pityriasis Rosea in Korea

BackgroundPityriasis rosea (PR) is a papulosquamous eruption with generally unknown origin but suspected to be related to viral etiologies. The clinicopathological spectrum of several disorders with viral etiologies has been altered after the coronavirus disease 2019 (COVID-19) pandemic. The author group could experience coherent histological alterations in PR after the COVID-19 pandemic. This study aimed to investigate how the clinicopathological findings of PR were changed after the COVID-19 pandemic.MethodsPatients (n = 11) diagnosed with PR based on the clinical manifestations and skin biopsies between February 2018 and October 2019 and 11 patients in February 2020 and October 2021 were retrospectively analyzed by investigating the medical records.ResultsThe patients with PR during the COVID-19 pandemic demonstrated statistically significant histopathological alterations from classic brisk and dense infiltration pattern to dormant and sparse infiltration and psoriasiform-dominant patterns (P = 0.019). PR was associated with more frequent pruritus during the pandemic period (P = 0.027).ConclusionIn conclusion, PR demonstrated a significant histopathological alteration with more frequent pruritus during the COVID-19 pandemic. The comparative results about clinicopathological findings of PR will provide a useful reference for dermatologists in the diagnostic process of PR in the COVID-19 pandemic.     

Serial blood concentration of polyethoxylated tallow amine and clinical presentations in acute herbicide poisoning

<正>1Department of Emergency Medicine, Chungnam National University Hospital, Daejeon 35015, South Korea2Department of Emergency Medicine, College of Medicine, Chungnam National University, Daejeon 35015, South Korea3Forensic Toxicology Division, National Forensic Service, Daejeon 34054, South Korea4Department of Emergency Medicine, Chungbuk National University Hospital, Cheongju 28644, South Korea Corresponding Author:Wonjoon Jeong, Email:gardenjun@hanmail.net     

Improved treatment outcome of pembrolizumab in patients with nonsmall cell lung cancer and chronic obstructive pulmonary disease

Emerging immune profiling data suggest a higher sensitivity to immune checkpoint inhibitors (ICIs) in nonsmall cell lung cancer (NSCLC) patients with chronic obstructive pulmonary disease (COPD), compared to those without COPD. This study aimed to investigate the clinical impact of COPD on the treatment response to ICIs in a large number of patients with NSCLC. In total, 133 patients with spirometry test results were retrospectively identified among those who received palliative pembrolizumab for NSCLC. COPD was defined as pre-bronchodilator forced expiratory volume in 1 s/forced vital capacity <0.7. Overall survival (OS), progression-free survival (PFS), and objective response rate were analyzed according to the presence of COPD. Spirometry-based COPD was present in 59 (44%) patients. Patients with COPD had better OS (hazard ratio [HR] for death, 0.45; 95% confidence interval [CI], 0.26–0.78) and PFS (HR for disease progression or death, 0.50; 95% CI, 0.31–0.79) than those without COPD. These associations persisted after adjusting for potential confounders including smoking history. The response rate was also higher in patients with COPD than in those without COPD (38.2% vs. 20.5%, p = 0.028). Spirometry-defined COPD was associated with a significantly longer OS and PFS in patients with NSCLC treated with palliative pembrolizumab. Identifying coexisting COPD could predict favorable treatment outcomes in patients with NSCLC treated with pembrolizumab.     

Does throbbing pain have a brain signature?

Pain sometimes has a throbbing, pulsating quality, particularly when it is severe and disabling. We recently challenged the presumption that this throbbing quality is a sensory experience of arterial pulsations, but were unable to offer an alternative explanation for its rhythmic character. Here we report a case study of a woman with a history of daily headache consistent with the diagnosis of chronic migraine, but whose throbbing quality persisted long after the resolution of the headache. This chronic, daily, and persistent throbbing sensation, in the absence of headache pain, prompted closer examination for its neurophysiological correlate. By simultaneously recording the subjective report of the throbbing rhythm, arterial pulse, and high-density electroencephalogram, we found that the subjective throbbing rate (48 ± 1.7 beats per minute) and heart rate (68 ± 2 beats per minute) were distinct, in accord with our previous observations that the 2 are unrelated. On spectral analysis of the electroencephalogram, we found that the overall amount of activity in the alpha range (8 to 12 Hz), or alpha power, increased in association with greater throbbing intensity. In addition, we also found that the rhythmic oscillations of overall alpha power, the so-called modulations of alpha power, coincided with the timing of the throbbing rhythm, and that this synchrony, or coherence, was proportional to the subjective intensity of the throbbing quality. This index case will motivate further studies whose aim is to determine whether modulations of alpha power could more generally represent a neurophysiological correlate of the throbbing quality of pain.