7,7'-Dimethoxyagastisflavone-induced apoptotic or autophagic cell death in different cancer cells

7,7'-Dimethoxyagastisflavone (DMGF), a biflavonoid isolated from the needles of Taxus × media cv. Hicksii, was evaluated for its antiproliferative and antineoplastic effects in three human cancer cell lines. Interestingly, DMGF caused cell death via different pathways in different cancer cells. DMGF induced apoptosis, activated caspase-3 activity and changed the mitochondrial membrane potential in HT-29 human colon cancer cells. However, the apoptotic pathway is not the major pathway involved in DMGF-induced cell death in A549 human lung cancer cells and HepG2 human hepatoma cells. Treatment with 3-MA, an inhibitor of autophagy, significantly decreased DMGF-induced cell death in HepG2 and A549 cells, but did not affect DMGF-induced cell death in HT-29 cells. Following DMGF treatment, the HepG2 cells increased expression of LC3B-II, a marker used to monitor autophagy in cells. Thus, DMGF induced apoptotic cell death in HT-29 cells, triggered both apoptotic and autophagic death in A549 cells and induced autophagic cell death in HepG2 cells.     

Embryotoxicity of micropore filters used in liquid sterilization

Microfiltration is the usual method of sterilization of tissue culture media. The filtrates of eight commercial filters were tested for embryotoxicity using mouse embryo growth. Four of five disk filters tested showed embryotoxicity in the first 5 ml of filtrate and the three largercapacity filters showed embryotoxicity for up to the first 10 ml of filtrate. The ethylene oxide-sterilized filters appeared to give poorer results than the gamma-irradiated filters. The importance of discarding the initial filtrate or preflushing such filters before use is emphasized.     

获取高质量生物样品图象的电镜技术浅析

获取高分辨率和高反差的生物样品电镜图象受许多因素的影响,它包括切片厚度的选择,电镜的校直合轴、加速电压的选择、以及聚焦方法和曝光时间等。除生物样品制备技术这一重要因素外,必须考虑到上述各因素间的相互关系及其综合选择、然后才有可能获得高质量的生物样品的超微结构图象。     

Diagnosis and Prevention of Hypersensitivity Reactions to Iodinated Contrast Media

Iodinated contrast media (ICM) have become one of the major causes of drug hypersensitivity reactions (HSRs) related to increasing numbers of ICM-based radiological imaging procedures. Strategies for diagnosing and preventing ICM-induced HSRs have not been uniformly standardized yet. However, advances have been made based on the results of recent research. A previous history of hypersensitivity to ICM is the most significant risk factor for developing HSR by ICM. Avoidance of culprit agents and premedication is the main strategy to prevent recurrences of HSRs in high-risk patients. In addition, we strongly recommend identifying sensitized ICM using skin tests to determine immunoglobulin E-mediated or delayed-type allergy and to guide the choice of an alternative contrast agent. ICM provocation test procedures have been established and are helpful in selected cases. In this paper, we review how to evaluate patients who have experienced immediate or delayed HSRs caused by ICM to minimize the risk of recurrence and discuss unmet needs that require further research.     

Experimentally induced otitis media with effusion following inoculation with the outer cell wall of nontypable Haemophilus influenzae

Summary Previously, we extracted lipopolysaccaride endotoxin (LPS) from an axenic culture of Haemophilus influenzae and inoculated it into the middle ears of guinea pigs, inducing temporary serous effusions. In the present study, we tried to clarify whether the immunological mechanism responsible for producing the otitis media following outer cell wall inoculation was persistent. We extracted the outer cell wall from nontypable H. influenzae, using Zollinger's method, and inoculated extracts into the middle ears of guinea pigs that had previously received three injections of nonviable H. influenzae in Freund's complete adjuvant. Histological evaluations were performed from day 2 to day 24. Effusions and mucosal changes persisted for a longer time than in the LPS-inoculated model. Hypertrophied mucosae and increased numbers of goblet cells with hypersecretion were visible in the specimens on days 23–24. The condition seemed to show a greater similarity to chronic otitis media with effusion in children than did the LPS-inoculated model. We concluded that both the biological activity of the outer cell wall and immunological mechanisms might induce prolonged otitis media. We speculate that not only single middle ear infection but also general infections and repetitive middle ear infections may contribute to prolonged otitis media.     

咽鼓管置管对预防鼻咽癌放疗后分泌性中耳炎的作用

目的 探讨咽鼓管置管在预防鼻咽癌（nasopharynged carcinoma，NPC）放疗后分泌性中耳炎（secretory otitis media，SOM）中的价值。方法 将60例NPC患者随机分成两组，每组各30例，一组患者在鼻内窥镜下经咽鼓管置管为实验组。另一组不置管者为对照组。两组患者均接受常规放射治疗，分析两组患者放疗中和放疗结束后第1天及第3个月时SOM发生率的差异及原因。结果 放疗量过半时，实验组2例发生SOM（6．67％），对照组5例发生SOM（16．67％），差异无统计学意义（χ^2=1．456，P=0．228）。放疗结束第1天实验组6例（20．00％）发生SOM，对照组14例（46．67％）发生SOM，差异有统计学意义（χ^2=4．800，P=0．028）。放疗结束第3个月实验组8例（26．67％）发生SOM，对照组16例（53．33％）发生SOM，差异有统计学意义（χ^2=4．444，P=0．035）。结论 咽鼓管置管能有效地降低NPC患者放疗后SOM的发生率。     

兔VX2舌癌转移淋巴结经静脉超声造影实验研究

目的 研究经静脉超声造影后兔VX2舌癌转移淋巴结的增强形态和增强方式,探讨应用静脉超声造影诊断颈淋巴转移的可行性.方法 将20只新西兰大白兔随机分为2组:VX2舌癌颈淋巴转移组(12只)和颈淋巴结炎性增生组(8只).经耳缘静脉注射超声造影剂,采用实时灰阶谐波超声造影成像技术观察两组淋巴结的增强形态和增强方式.采用Fisher确切概率法分析增强的形态和方式.结果 超声造影后,炎性增生组和淋巴转移组每只兔的每侧颈部均检出1枚增强的淋巴结.炎性增生组淋巴结均为均匀增强,且增强自中央开始.淋巴转移组中11只兔颈淋巴结为不均匀增强,其中3只为从周边开始的不均匀增强,8只为从周边及中央开始的不均匀增强;另1只兔颈淋巴结为均匀增强,增强从中央开始.结论 超声造影后,肿瘤转移淋巴结增强表现为从周边开始或周边和中央开始的不均匀增强,此特征对诊断颈淋巴转移有一定的参考价值.     

医学视听教材的现状和设计制作趋势分析

文章在总结医学视听教材制作现状的基础上,从医学视听教材设计制作的设备、人员专业素质、环境的变化所显示的以人为本的时代精神、娱教性和片段医学视听教材越来越得到关注以及制作队伍出现的泛化现象等方面论述了其发展趋势。