藏羚羊和藏系绵羊左心室收缩功能的比较研究

目的:探讨藏羚羊适应高原低氧环境的左心功能特点。方法:捕捉海拔4 300 m藏羚羊9只、藏系绵羊10只运至格尔木(海拔2 800 m)实验基地。测定二者的心脏/体重比(HW/BW)、右心室/(左心室+室间隔)重量比[RV/(LV+IVS)];应用心导管技术测定心率(HR)、收缩压(SBP)、舒张压(DBP)、左室等容收缩期心室内压力上升最大速率和左室等容舒张期心室内压力下降最大速率(±dp/dt)。以格尔木市的氧浓度(21.1%)为基线,分别给予更低浓度氧14.6%、12.5%(分别相当于海拔5 300 m、6 300 m)的低氧吸入15 min后重复测定以上指标。应用透射电镜观察心肌超微结构。结果:藏羚羊HW/BW显著高于藏系绵羊(P0.01),基础状态下藏羚羊SBP低于藏系绵羊(P0.05),+dp/dt与藏系绵羊比无显著差异,吸入14.6%和12.5%的低氧气体后藏羚羊+dp/dt分别升高至145.1%和148.1%,而藏系绵羊分别降低至68.4%和70.5%(P0.05);电镜下观察藏羚羊心肌超微结构与藏系绵羊比较,其心肌细胞线粒体较为丰富。结论:藏羚羊心脏对高海拔低氧环境的适应,是通过增加心脏器官的重量及心肌细胞线粒体的含量来实现,其心肌收缩功能的适应性特征为:在静息状态下以较低的左心室心肌收缩力来降低氧耗量以此适应高原低氧环境,而以海拔更高的较低氧浓度为应激条件下,左心室心肌收缩力明显升高。提示:藏羚羊作为高原适应性动物,经过漫长的自然选择其心脏对高原低氧环境的适应不同于藏系绵羊。     

红景天抑制人脐静脉内皮细胞生长的初步研究

目的:利用体外培养人脐静脉内皮细胞,观察中药红景天对细胞生长的影响,初步探讨急、慢性高原病患者服用中药红景天防治高原病及改善症状等的作用机制。方法:培养人脐静脉内皮细胞EVC-304,设对照组与加药组,加药组分别加入不同浓度的红景天,培养3d后计数。加药组及对照组细胞用瑞氏染料染色并拍照。收集细胞以流式细胞术检测细胞周期。结果:对照组细胞形态正常,成梭形,排列紧密,分散均匀。加药组细胞数量明显减少,细胞皱缩,聚集成团,形态各异。流式细胞术检测显示加药组G1期细胞含量增多,S期细胞减少。结论:红景天具有抑制血管内皮细胞生长的作用,可能是通过抑制细胞的增殖来抑制内皮细胞生长。抑制血管内皮细胞生长对于阻止血管内膜增生,防止形成肺动脉高压,降低慢性高原病发病率具有实际应用意义。     

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目的了解福建省北部地区政和县儿童牙弓宽度,为研究当地儿童牙弓宽度生长发育的规律和特点提供依据。方法2003年6月至2005年6月选取福建省建瓯市政和县3～9岁儿童321名,采用电子数显游标卡尺及分规对其上下颌模型的牙弓宽度进行测量,并对数据进行统计学分析。结果牙弓宽度在多数年龄组、分段中存在显著性别差异。除下颌第一恒磨牙间牙弓宽度之外,各段牙弓宽度>7～9岁组均显著大于>5～7岁组。而各段牙弓宽度>5～7岁组与3～5岁组相比,除上颌乳尖牙间牙弓宽度>5～7岁组显著大于3～5岁组,其余各段牙弓宽度差异均无统计学意义。结论>7～9岁是牙弓宽度显著增长的年龄段,其原因可能与恒切牙的萌出有关。     

Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography

The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study.     

Malignant uveal melanoma and simulating lesions: MR imaging evaluation

Twenty-one patients with intraocular disease were studied by magnetic resonance (MR) imaging and computed tomography (CT). In 13 cases, malignant uveal melanoma was considered the likely diagnosis. Both imaging methods were accurate in determining the location and size of uveal melanomas. MR imaging was superior for the assessment of possible associated retinal detachment, for assessment of vitreous change, and for differentiating uveal melanoma from choroidal hemangioma and choroidal detachment. A case of retinal gliosis could not be differentiated from uveal melanoma by either technique. Uveal melanomas appeared as hyperintense lesions on T1-weighted images and as hypointense lesions on T2-weighted images. High signal intensity of the vitreous was observed in patients with vitritis and in those who were thought to have protein leaking into the vitreous as a result of impairment of the retinal-blood barrier.     

经胸乳径路腔镜甲状腺手术180例的临床研究

目的探讨经胸乳径路腔镜甲状腺手术技巧及其并发症的防治。方法回顾分析2005年3月至2009年12月经胸乳径路腔镜甲状腺手术180例患者的临床资料。结果本组178例腔镜甲状腺手术顺利完成,2例中转开放手术,其中1例为结节性甲状腺肿,因甲状腺体积大,空间狭小中转开放手术,另1例为原发性甲状腺功能亢进,因粘连严重、创面广泛渗血中转开放手术。全组手术时间70～190 min,平均110 min。术中出血量5～75 ml。术后出现皮肤瘀斑2例,抽搐1例,均于2周后恢复正常。声音嘶哑1例,1个月后恢复正常。住院时间3～6 d,平均4.5 d。结论经胸乳径路腔镜甲状腺手术是一种极富技巧性的手术,甲状旁腺损伤和喉返神经损伤是其严重并发症,规范手术操作能有效减少并发症的发生。     

数字化导航模板辅助全膝关节置换的模拟研究

 目的 探讨数字化导航模板辅助全膝关节置换的准确性和可行性。方法 取成年尸体下肢标本 20具,随机分为导航模板组和传统方法组,每组 10具 20个膝关节。导航模板组术前行下肢全长 CT扫描,利用逆向工程软件对 CT数据进行处理,设计与股骨远端和胫骨近端匹配的可定位截骨平面和外旋轴的导航模板,通过快速成型机制作模板实物用于尸体标本的全膝关节置换手术操作。传统方法组按常规全膝关节置换手术操作。术后通过 CT扫描比较两种方法定位的截骨准确性。结果 导航模板与股骨髁和胫骨平台贴合紧密,无明显移动。导航模板组 18个膝关节的股骨远端和胫骨近端截骨面与下肢机械轴垂直,2个膝关节内翻; 17个膝关节后髁截骨面与通髁轴完全平行,3个膝关节有成角。传统方法组 20个膝关节均出现下肢机械轴内外翻,其中 5个膝关节大于 5°; 20个膝关节均出现后髁截骨面与通髁轴成角,其中 10个膝关节大于 3°。结论 导航模板法的股骨远端、胫骨近端和股骨外旋截骨准确性均高于传统手术方法。