Intracranial hemorrhage: gradient-echo MR imaging at 1.5 T. Comparison with spin-echo imaging and clinical applications

Fifty-seven patients with hemorrhagic intracranial lesions were examined with magnetic resonance (MR) imaging at 1.5 T with use of both spin-echo (SE) and gradient-echo-acquisition (GEA) techniques to assess the clinical applications and limitations of GEA in evaluation of intracranial hemorrhage at high field strength. All GEA images were obtained with a long echo time and short flip angle to emphasize T2*-based contrast. In 30 of 61 cases, GEA images demonstrated more hemorrhagic lesions than SE images. In 14 of 61 cases, GEA images failed to depict the lesion or obscured the specific diagnosis (as depicted by SE MR imaging). The authors believe that GEA imaging in its current form has a limited but definite adjunctive role in the evaluation of intracranial hemorrhage at high field strength.     

人参二醇皂甙和三醇皂甙对兔纹状体ATP酶的影响

本文报道用体外给药法,观察了PDS和PTS对纹状体ATP酶(Na⁺、K⁺-ATP酶,Ca²⁺-ATP酶及M²⁺-ATP酶)的影响。结果发现PDS和PTS对Na⁺,K⁺-ATP酶都有明显的抑制作用,且随PDS和PTS浓度的高低,其抑制作用增强或减弱;对Ca²⁺-ATP酶,PDS在10^-5g/ml时有激活作用,当浓度增高到10^-3g/mL时则转为抑制,而PTS仅为抑制效应;对于Mg²⁺-ATP酶能被PDS所兴奋,而被PTS所抑制。此结果表明PDS和PTS对中枢神经系统的作用,可能与其影响脑内ATP酶有密切的内在联系。     

多形性透明血管扩张性肿瘤(PHAT):41例分析支持来自一个特有前驱病变的演化(英)

PHAT是一种罕见的低度恶性肿瘤，特征性的表现为伴有含铁血黄素沉着的问质细胞不典型增生，部分有血栓形成的扩张血管壁周围透明变性及数量不等的炎细胞浸润。多年来，作者偶尔观察到部分黏液样梭形细胞单一成分（暂称为早期PHAT）合并经典的PHAT。在某些病例中，这种单一病变独立出现，提示是PHAT演变的早期阶段。为了进一步证实这种设想，更好地阐述PHAT的长期生物学行为，作者复习了所遇到的这些病变。41例均为已确诊的会诊病例。     

Stable azole drug resistance associated with a substrain of Candida albicans from an HIV-infected patient

Oral candidiasis is one of the earliest and most frequent complications of a failing immune system in HIV-infected individuals. For several years, oral candidiasis has been treated effectively with azole drugs, the one most frequently used is fluconazole. Unfortunately, extensive use of the drug for treatment and prophylaxis has led to treatment failure in an increasing number of patients. In most of these cases, strains of C. albicans isolated from the infection are less susceptible to fluconazole. The development of azole resistance in strains of C. albicans has been studied biochemically and more recently with molecular techniques. One excellent example of the development of azole resistance in C. albicans has been documented in a series of 17 C. albicans isolates from a single patient over a 2-year period. During this time, the patient experienced 14 episodes of oral candidiasis and was treated with increasing doses of fluconazole. Molecular and biochemical analyses confirms that the isolates are the same strain of C. albicans and that the resistance in these isolates is stable over 600 generations, suggesting that the changes in this strain are genetic in nature. In addition, the development of resistance is correlated with the identification of a substrain or variant of the original strain, as identified by restriction fragment length polymorphism (RFLP) analysis with the moderately repetitive probe, Ca3. The analysis of this series of isolates demonstrates that azole drug resistance is associated with several small genetic changes, each of which contributes to the overall resistance of the strain. Clearly, continual use of azole drugs by a patient can select for genetic changes that render oral candidiasis refractory to treatment.     

犬骨髓单个核细胞诱导分化为平滑肌样细胞

目的:探讨体外诱导骨髓单个核细胞分化为平滑肌样细胞的可行性,为构建组织工程器官提供种子细胞。方法:实验于2005-10/2006-12在教育部重点实验室,实验室等级1级的首都医科大学宣武医院外科实验室完成。实验材料:体质量20～30kg成年雌性杂种犬6只,由北京市科宇实验动物养殖中心提供(许可证号为SCXK(京)2000-0015),动物饲养级别1级。实验方法:①骨髓单个核细胞的分离培养:穿刺健康成年实验犬髂前上棘,抽取骨髓10mL,加入肝素抗凝,以等体积PBS充分混匀,4℃条件下转入离心管中,取20mL淋巴细胞分离液,将稀释骨髓按1∶1小心加在分离液的界面上,用水平离心机以1500r/min离心10min后,单个核细胞位于血浆和离心液界面层。吸取界面层单个核细胞层,以含体积分数为0.1胎牛血清的PBS冲洗3次,备用。②骨髓单个核细胞诱导分化为平滑肌样细胞:将收获的犬骨髓单个核细胞以由含体积分数为0.15胎牛血清的DMEM/F12混合培养液、0.5μg/L内皮细胞生长因子、2μg/L碱性成纤维生长因子、10μg/L血小板源性生长因子BB、100μg/L胰岛素样生长因子、1mmol/L磷酸维生素C、0.04mmol/L脯氨酸组成的诱导培养基重悬,以1×109L-1种植于胶原铺底的培养瓶中,置37℃、含50mL/LCO2饱和湿度培养箱中,进行诱导培养。倒置相差显微镜下观察细胞形态特征。在诱导培养后第1,3,5,7,9,11天绘制细胞生长曲线。采用免疫组织化学方法进行细胞表型鉴定,并评价细胞生长增殖情况。结果:①骨髓单个核细胞向平滑肌样细胞诱导的细胞生长曲线:接种第1,3,5,7,9,11天计数每孔细胞数分别为(2.73±0.18)×108,(3.17±0.36)×108,(7.35±1.28)×108,(23.61±1.56)×108,(53.48±3.47)×108,(48.51±5.36)×108L-1。②免疫组织化学方法鉴定细胞表型:原代细胞仅少数α-平滑肌肌动蛋白染色明显阳性,明显阳性细胞约占总数的(60.5±5.9)%,细胞内肌丝样结构不明显,而平滑肌肌球蛋白重链、碱性钙调宁蛋白染色阴性;P3代细胞生长5d,细胞生长汇合后,绝大部分诱导后细胞α-平滑肌肌动蛋白、平滑肌肌球蛋白重链、碱性钙调宁蛋白染色阳性,可见胞浆内清晰的肌丝样结构,明显阳性细胞分别占细胞总数的(86.2±13.5)%,(78.7±10.2)%,(76.63±13.8)%,明显高于原代细胞(P<0.05)。③平滑肌样细胞的亚型分析:原代细胞爬片标本Flk-1染色多数呈阳性,第3代细胞Flk-1染色几乎阴性,阳性细胞胞膜、胞浆着色呈棕黄色。原代及传代细胞Vimentin染色均呈阳性,阳性细胞胞浆着棕黄色。本组细胞Desmin染色阴性。结论:骨髓单个核细胞可以被定向诱导成为平滑肌样细胞,能够满足组织工程种子细胞的要求。     

犬原位回肠构建全尿道、膀胱的实验方法特征

目的:探索犬膀胱全切后以回肠构建全尿道、膀胱术的实验方法。方法:实验于2004-12/2005-07在吉林大学药学院生物工程研究室完成。体质量13kg的雄性京犬12只,术前禁食24h,以30g/L戊巴比妥钠按1mL/kg剂量对犬麻醉。取腹部正中切口,切除膀胱及尿道。在距回盲部约10cm处取一段30cm带血供的回肠袢,恢复肠道的连续性。取25cm回肠沿着肠管系膜的对侧缘纵向剖开,将剖开的肠管对折缝合成袋状,并将两侧输尿管种植于回肠新膀胱的适当位置。取5cm回肠剥离黏膜层并缝制成管状,构建尿道,在回肠新膀胱的底部戳孔与其缝合。连接在膀胱及尿道的原位,术中静点氧氟沙星100mL(含氧氟沙星0.2g/L)、葡萄糖注射液250mL、生理盐水250mL、缝合术后刀口,并静点氧氟沙星0.2g/d,连续给药7d,1周后正常进食、继续饲养1个月,观察动物排尿情况,行X射线影像学检查。结果:9只犬进入结果分析,另3只由于麻醉过度死亡。术后1个月观察实验动物犬,进食正常,排尿正常。术后4周X射线造影检查显示:贮尿囊显影良好,无梗阻;回肠替代膀胱充盈,肠黏膜替代尿道再生状况良好。结论:建立的犬膀胱全切原位回肠代膀胱、尿道术的实验方法,可做为组织工程膀胱、尿道移植研究的模型。     

骨髓干细胞移植后Western blot免疫印迹分析鼠抗肌萎缩蛋白表达的变化

目的:Western blot免疫印迹分析骨髓干细胞移植后mdx鼠抗肌萎缩蛋白表达的变化。方法:实验于2004-09/12在中山大学附属第一医院神经科实验室完成。①选取7～8周龄mdx鼠25只,随机数字表法分为骨髓移植4,8,12,16周组、空白对照组,5只/组。另选取4～6周龄C57鼠20只作为供体鼠,10周龄C57鼠5只作为阳性对照组。②各组在移植前均给予照射剂量为7Gy的放疗预处理。放疗完毕后,骨髓移植4,8,12,16周组均进行尾静脉细胞移植,移植细胞数为2×107/只,0.3～0.5mL;空白对照组、阳性对照组尾静脉输入0.3mL磷酸盐缓冲液。③骨髓移植4,8,12,16周组分别于对应时间点处死,取其腓肠肌,制备抗肌萎缩蛋白样品,进行抗肌萎缩蛋白Western blot免疫印迹分析,以GAPDH作为内参。结果:25只7～8周龄mdx鼠、5只10周龄C57鼠全部进入结果分析。骨髓干细胞移植后抗肌萎缩蛋白Western Blot免疫印迹分析结果:空白对照组无抗肌萎缩蛋白的表达;骨髓移植4周组仅可见抗肌萎缩蛋白的微弱表达,dystrophin/GAPDH灰度比值约为0.095±0.267;骨髓移植12周组约为0.218±0.338;随骨髓移植时间的延长抗肌萎缩蛋白表达量逐渐增加,移植后16周的表达量较移植后8周明显增加(0.393±0.385,0.173±0.284;t=6.062,P<0.05),但仍明显低于阳性对照组1.172±0.328(t=3.14,P<0.05)。结论:骨髓干细胞移植mdx鼠后应用WesternBlot免疫印迹分析可于不同时间检测到抗肌萎缩蛋白的表达,且随移植时间延长表达量增多,提示骨髓干细胞移植可长久持续参与受损骨骼肌的修复与再生。