冬凌草甲素聚乙二醇功能化氧化石墨烯纳米粒的制备及抗结肠癌实验研究

目的制备负载冬凌草甲素(oridonin,ORI)的聚乙二醇功能化氧化石墨烯(PEGylated graphene oxide,GO-PEG)纳米粒(nanoparticles,NPs),并探讨其对结肠癌的抑制作用。方法利用酰胺化反应将端基为氨基的四臂聚乙二醇(PEG)连到氧化石墨烯(GO)上,并通过红外光谱(IR)和差示-热重联用热分析仪(TGA)等对其进行表征;再通过物理共混的方法在GO-PEG上负载抗肿瘤药物ORI,紫外光谱(UV)法测其包封率和载药率,MTT法测定载药体系对人结肠癌细胞SW620和HT29的增殖毒性,并建立荷瘤裸鼠模型考察其体内抗肿瘤活性。结果 IR和TGA测定结果表明PEG已成功偶联到GO上,UV法测得ORI-GO-PEG的包封率和载药率分别为95.81%和48.92%,且在各种生理溶液中具有良好的稳定性。体外细胞毒性实验结果表明,与ORI裸药相比,ORI-GO-PEG-NPs对结肠癌细胞的杀伤能力更强。体内抑瘤实验进一步发现,ORI-GO-PEG-NPs可以更好地抑制体内SW620肿瘤的生长。结论制得的ORI-GO-PEG-NPs具有优良的载药性能和较强的抗结肠癌作用,为今后开发抗肿瘤药物纳米给药系统提供了实验依据。     

虎杖苷对大鼠脑出血性损伤脑脊液中兴奋性氨基酸动态变化的影响

目的:观察虎杖苷对大鼠脑出血损伤后脑脊液中兴奋性氨基酸动态变化和脑组织含水量的影响,探讨虎杖苷对脑出血损伤的治疗作用及其作用机制。方法:采用微透析-高效液相色谱法建立天门冬氨酸(Asp)、谷氨酸(G lu)的测定方法;用Ⅶ型胶原酶诱导建立大鼠脑出血模型,观察虎杖苷对大鼠脑出血后0,6,12,24,36,48,60,72,84,96,108 h脑脊液内天门冬氨酸、谷氨酸含量的动态变化,并断头取脑检测脑组织含水量。结果:天门冬氨酸和谷氨酸含量在大鼠脑出血后24 h内迅速升高,并于24 h达到最高,随后逐渐开始降低。虎杖苷治疗后,天门冬氨酸和谷氨酸含量均上升缓慢,分别在12~72,6~84 h与同时段模型组比较有显著性差异(P0.01或P0.05),84,96 h后与同时段模型组相比无显著性差异。与假手术组比较,模型组脑含水量明显较高,虎杖苷组则明显降低(P0.01)。结论:虎杖苷能抑制脑出血后脑脊液中ASP,G lu含量升高,能明显抑制脑出血造成的脑水肿,表明虎杖苷抗脑出血损伤的作用机制可能与其抗脑出血后兴奋性氨基酸含量的升高有关。     

鼻腔内机械振荡刺激对健康人群静息态脑电图相对功率及有效连接的影响

鼻腔内机械振荡刺激(iMVS)是一种新型的无创神经刺激技术,可提升边缘系统内在功能活性从而改善自主神经平衡.通过分析iMVS对健康人群脑电图(EEG)相对功率以及EEG有效连接的影响,探索iMVS的神经生理机制.将22名健康成年被试随机均分为刺激组与对照组,并对11名刺激组被试两侧鼻腔各进行10 min的iMVS,11...     

肝门部胆管癌的CT与MRI对照研究

目的:评估CT与MRI在肝门部胆管癌的诊断价值。材料与方法:回顾性分析16例经CT与MRI检查且为手术病理证实的肝门部胆管癌的CT与MRI表现,比较两种检查手段对病灶的显示情况及定性诊断的准确率。结果:16例肝门部胆管癌CT与MRI均表现为肝内胆管不同程度的扩张,其中14例肝门部见软组织肿块,2例MRI见胆管壁增厚呈鼠尾状改变,4例门脉受累,6例 CT发现淋巴结肿大。CT与MRI定性诊断的准确率及对病灶的显示无明显差异。结论:CT与MRI是检查肝门部胆管癌的有效手段。MRI在显示肝门部肿块的大小、范围及沿胆管壁浸润方面比CT优越,尤其对早期肝门部胆管癌诊断更具价值。     

实时三维超声在产前胎儿超声检查中的初步应用

目的探讨实时三维超声在产前胎儿超声成像中应用的临床价值。方法对26例孕龄16～41周的正常适龄胎儿进行实时三维超声检查。观察胎儿的心脏、颜面部、头颅、胸腹部各重要解剖结构。实时显示三维图像,或者在检查结束后脱机分析图像。结果26例胎儿均获得满意的实时三维图像,包括心脏、颜面部、头颅、胸腹部结构。其中26例观察了心脏,14例观察了颜面部,12例观察了头颅,6例观察了胸腹部。结论实时三维超声能够实时直观地显示胎儿各部位解剖结构的三维立体图像,比传统的二维超声提供更直观的图像信息,其在胎儿先天性畸形显像及筛查中具有重要的应用价值。     

Rutin exhibits hepatoprotective effects in a mouse model of non-alcoholic fatty liver disease by reducing hepatic lipid levels and mitigating lipid-induced oxidative injuries

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive accumulation of hepatic lipids and oxidative injury of hepatocytes. Rutin is a natural flavonoid with significant roles in combating cellular oxidative stress and regulating lipid metabolism. The current study aims to investigate the molecular mechanisms underlying rutin's hypolipidemic and hepatoprotective effects in nonalcoholic fatty liver disease. Rutin treatment was applied to male C57BL/6 mice maintained on a high-fat diet and HepG2 cells challenged with oleic acid. Hepatic lipid accumulation was evaluated by triglyceride assay and Oil Red O staining. Oxidative hepatic injury was assessed by malondialdehyde assay, superoxide dismutase assay and reactive oxygen species assay. The expression levels of various lipogenic and lipolytic genes were determined by quantitative real-time polymerase chain reactions. In addition, liver autophagy was investigated by enzyme-linked immunosorbent assay. In both fat-challenged murine liver tissues and HepG2 cells, rutin treatment was shown to significantly lower triglyceride content and the abundance of lipid droplets. Rutin was also found to reduce cellular malondialdehyde level and restore superoxide dismutase activity in hepatocytes. Among the various lipid-related genes, rutin treatment was able to restore the expression of peroxisome proliferator-activated receptor alpha (PPAR-α) and its downstream targets, carnitine palmitoyltransferase 1 and 2 (CPT-1 and CPT-2), while suppressing those of sterol regulatory element-binding protein 1c (SREBP-1c), diglyceride acyltransfase 1 and 2 (DGAT-1 and 2), as well as acyl-CoA carboxylase (ACC). In addition, rutin was shown to repress the autophagic function of liver tissues by down-regulating key autophagy biomarkers, including tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β). The experimental data demonstrated that rutin could reduce triglyceride content and mitigate oxidative injuries in fat-enriched hepatocytes. The hypolipidemic properties of rutin could be attributed to its ability to simultaneously facilitate fatty acid metabolism and inhibit lipogenesis.     

各类医用电气设备标准间电气安全指标的差异

本文统计了各类医用电气设备标准，分析了各标准间电气安全指标的差异，以指导临床工程师在不同医用电气设备的安全测试、维修或预防性维护丁作中采用合适的电气安全标准。     

HucMSC-Derived Exosomes Mitigate the Age-Related Retardation of Fertility in Female Mice

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