B超图像纹理的复杂性分析

本文提出一种复杂性度量法对肝脏Ｂ超图像纹理的分类进行了研究,图像的灰度值复杂性作为纹理特征。     

Internet上的医学杂志网址

随着信息技术的飞速发展,Internet对社会各个方面都产生了前所未有的影响,医学方面也不例外。特别是许多专业医学期刊都在网上发布期刊电子版,电子版期刊一般都比原版期刊早出版1～2个月,提高了期刊利用的时效性,而且阅读费用低廉,这引起了许多医学工作者的关心和兴趣。现介绍一个在线医学杂志网     

应用脉冲多普勒估测右心室dp／dtmax方法的评价

目的通过动物实验及临床研究评价右心室射血期肺动脉脉冲多普勒频谱参数估测右心室收缩功能的可行性。方法6条健康犬及25例先心病患儿。1.在右心室正性肌力及改变前后负荷干预下,观察实验犬血流频谱最高速度（Vp）、加速时间（AT）、平均加速度（Am）及Vp2／AT等肺动脉射血期脉冲多普勒参数与右心室dp／dtmax的关系。2.测算先心病患儿上述各肺动脉射血期血流频谱参数并与心导管造影术中右室dp／dtmax测值比较。结果1．实验犬中仅Vp及Vp2／AT在右心室正性肌力及前后负荷干预下始终与右室dp／dtmax呈高度相关。2先心病患者肺动脉血流Vp、Am及Vp2／AT与右心室dp／dtmax成非常显著相关。结论右室Vp及Vp2／AT可用于右空心肌收缩力的估测。     

In utero methylmercury exposure differentially affects the activities of selenoenzymes in the fetal mouse brain

Pregnant ICR mice were subcutaneously injected with 0,5, or 3x3 mg Hg/kg of methylmercury (MeHg) on days 12,13, and 14(G12-14) of gestation and were sacrificed on G17. Activity of selenoenzymes, including glutathione peroxidase (GPx) and 5'- or 5-iodothyronine deiodinases (5'-DI, 5-DI), was determined in fetal brain and placenta. MeHg did not affect the concentration of Se in these tissues, while it significantly inhibited the activity of GPx in the fetal brain and placenta, but not in the maternal brain. Although the levels of thyroid hormones in the maternal and fetal plasma were not affected by MeHg, 5-DI decreased and 5'-DI increased in the fetal brain, as if they had responded to hypothyroidism. Because the level of T4 in the fetal plasma was not affected by MeHg, these changes in enzymatic activities may result in a harmful excess of T3 in the fetal brain. In addition, 5-DI activity was increased in the placenta of MeHg-treated mice. These effects of prenatal MeHg exposure on fetal and placental DIs differed from those of dietary-induced Se deficiency, where the activities of DIs were decreased or not affected. Further evaluation of the effect of MeHg on selenoenzymes, especially 5-DIs, is warranted.     

HPLC法测定蔓荆子黄素的含量

以蔓荆子黄素为指标,用反相 ＨＰＬＣ法测定了蔓荆子中的含量,实验采用 Ｃ_(１８)柱,以甲醇－０．４％磷酸溶液（６０： ４０）为流动相,检测波长 ２５８ｎｍ,用外标法测定,回收率为 ９８．１８％,ＲＳＤ１．４６％,线性范围 ０．１５～０．７５μｇ。本法快速简便,重现性好,为蔓荆子质量控制提供了可靠的依据。     

不同手术切口对白内障术后视力和屈光力的影响

目的　评价白内障不同的手术切口对术后视力恢复的影响。方法　对１８６ 只眼老年性、并发性、发育性和无角膜瘢痕的外伤性白内障行ＥＣＣＥ（ＣＣＣ） 加ＩＯＬ。切口为１１ ｍ ｍ ,隧道６ ｍ ｍ 及反眉状５ ．５ ｍ ｍ 巩膜切口,手术后１ ｗｋ ,１ ｍ ｏ ,３ ｍ ｏ 进行视力和屈光检查与比较。结果　随着手术切口的缩小和手术切口的改进,角膜散光明显减少,视力明显提高。结论　提示反眉状隧道式白内障摘出术ＩＯＬ 术具有有效控制术后散光,全面重建视功能的优点     

股骨头缺血性坏死的介入治疗

目的 探讨介入治疗股骨头缺血性坏死的临床效果。方法 对13例16髋股骨头缺血性坏死．经患髋的旋股内、外动脉或闭孔动脉灌注溶栓药物及血管扩张药物等。结果 随访3～6个月．髋关节疼痛消失6髋，减轻8髋；功能恢复5髋，功能改善8髋。结论 介入治疗股骨头缺血性坏死，能改善股骨头血液循环，能有效地改善临床症状和髋关节的活动功能，其创伤小且安全可靠。     

Self-assembled nanoparticles of hydrophobically-modified polysaccharide bearing vitamin H as a targeted anti-cancer drug delivery system.

Vitamin H (biotin) was incorporated into a hydrophobically modified polysaccharide, pullulan acetate (PA), in order to improve the cancer-targeting activity and internalization of self-assembled nanoparticles. The biotinylated pullulan acetate (BPA) nanoparticles were prepared by a diafiltration method and the mean diameter was approximately 100 nm. Three samples of biotinylated pullulan acetate (BPA), comprising 7 (BPA 1), 20 (BPA 2), and 39 (BPA 3) vitamin H groups per 100 anhydroglucose units of PA, were synthesized. The critical aggregation concentrations (CAC) of the BPA nanoparticles in distilled water were 3.1 x 10(-3), 4.3 x 10(-3) and 6.8 x 10(-3) mg/ml for BPA 1, BPA 2, and BPA 3, respectively. Adriamycin (ADR) was loaded into the BPA nanoparticles as a model drug. The loading efficiencies and ADR content in the BPA nanoparticles decreased with increasing vitamin H content due to a lower hydrophobicity. The RITC-labeled BPA nanoparticles exhibited very strong adsorption to the HepG2 cells, while the RITC-labeled PA nanoparticles did not show any significant interaction. The degree of the interaction increased with increasing vitamin H content. Confocal laser microscopy also revealed that internalization of the BPA nanoparticles into the cancer cells depended on the vitamin H content.     

RMP-7及其衍生物对脂质体跨血脑屏障作用的影响

目的研究RMP-7及其衍生物对脂质体跨血脑屏障的促进作用。方法测定RMP-7与DSPE-PEG-NHS偶联的物质的量比；用血脑屏障的体外模型验证其生物活性；观察脑组织切片中伊文思蓝的荧光位置和强度，测定脑组织中伊文思蓝的浓度。结果RMP-7与DSPE-PEG-NHS偶联物质的量比为1∶1；RMP-7和DSPE-PEG-RMP-7能使过氧化合物酶跨血脑屏障体外模型的转运速率增加2～3倍，修饰脂质体后能使所包封的伊文思蓝在脑中的浓度增加。结论RMP-7与DSPE-PEG-RMP-7对脂质体跨血脑屏障均有促进作用，且后者效果更好。     

新疆药用桑树9个栽培群体的RAPD分析

目的 从DNA分子水平上分析新疆药用桑树资源9个栽培群体的遗传关系。方法 从100个随机引物中筛选出10个引物，用这10个引物做RAPD扩增，应用NTSYS软件对扩增结果进行聚类分析。结果 共扩增出108个位点。其中多态性位点91个，多态比例为84．26％，各群体间存在较明显的遗传分化。另外，获得药桑的8个特异位点。结论 RAPD分析结果与新疆药用桑树资源植物的遗传关系的传统划分是基本一致的。