重睑成形术结合眉埋线固定法治疗上睑皮肤松弛

目的介绍一种埋线法固定眉,结合重睑成形术治疗中青年上睑皮肤松弛的手术方案。方法应用3-0无损伤线皮内缝合,固定眉于眉骨骨膜上,再结合重睑成形术,去除上睑多余的皮肤,共治疗29例上睑皮肤松弛的患者。结果本组29例患者,术后Ⅰ期愈合。21例患者术后随访6个月至2年,均获得满意效果,上睑明显年轻化,无并发症。结论重睑成形术结合眉埋线固定法治疗上睑皮肤松弛,是一种简单有效的上睑年轻化治疗方案。     

恐惧应激对大鼠睾丸中Annexin5表达的影响

目的观察大鼠应激条件下睾丸组织中Annexin5表达的变化。方法建立SD大鼠的恐惧应激模型，分别取急性应激、急性对照、慢性应激、慢性对照SD大鼠睾丸，免疫组织化学和Western blotting分析Annexin5免疫定位和蛋白表达。结果急性应激组与对照组相比，免疫组化显示Annexin5都定位在间质细胞、支持细胞和成熟的精子头部，Western blotting分析发现Annexin5的表达降低了10．8％；慢性应激组与对照组相比，免疫组化结果显示Annexin5在精子头部的定位逐渐减少，应激1w和2w组，未见到Annexin5定位于精子头部，到了应激的3w和4w，发现Annexin5重新定位于精子的头部，而在间质细胞和支持细胞上的定位模式没有显著变化。Western blotting分析发现Annexin5的表达降低了17．4％。结论大鼠睾丸Annexin5参与了应激过程，急性应激条件下Annexin5表达降低。随着应激时间的延长，在慢性应激条件下，Annexin5的表达由减少之后而开始有缓慢增加。     

镁离子对大鼠弥漫性轴索损伤超微结构的影响

目的探讨镁离子(Mg^2 )对脑弥漫性轴索损伤(diffuse axonal injury，DAI)脑干超微结构的影响。方法选健康成年雄性SD大鼠36只，体重350～450g，将其随机分为实验组、对照组、空白组，每组为12只。采用改良Marmarou模型制作DAI模型，伤后30min分别给予MgSO4 250μmol／kg、等渗盐水0．2ml，伤后24h处死。用透射电镜分别检测脑干超微结构，并行综合组织损伤评分。结果伤后24h，对照组髓鞘分离，线粒体嵴明显肿胀；实验组未见髓鞘分离，线粒体轻度肿胀。实验组脑干综合组织损伤程度评分明显轻于对照组。结论Mg^2 可在超微结构水平阻止DAI轴索的继发性损害，对DAI具有一定的保护作用。     

健康青年急进高原后凝血纤溶系统改变的研究

目的探讨高原环境下,急进高原人群不同时相凝血及纤溶系统变化的基本规律.方法对从平原地区急进3 650 m高原前、急进高原后第3 d、第7 d第15 d及第30 d的30名健康青年血浆凝血酶时间(PT)、活化部分凝血活酶时间(APTT)、组织纤溶酶原激活物(t-PA)、纤溶酶原激活抑制物活性(PAI)、纤溶酶原(PLG)、D-二聚体含量(DD)进行检测,并与30名世居者作对照.结果健康青年急进高原3 d后其PT、APTT出现延长,t-PA活性增高,而PAI、Fg含量降低,与平原组相比有显著差异(P＜0.05).急进高原后7～30 d,其PT、APTT随移居时间延长而逐渐缩短,t-PA活性则逐渐降低,PAI、Fg逐渐增高,血液处于高凝状态.且急进高原30 d后,与平原人及世居组比较均有显著差异(P＜0.05).结论 高原环境下,急进高原青年凝血系统出现紊乱,表现为早期凝血与纤溶被激活,而后出现继发性纤溶受抑,凝血及纤溶的平衡被破坏,而使血液呈现高凝和继发纤溶状态.     

人髓核软骨样细胞的生物学特性观察

目的:探讨人髓核软骨样细胞的生物学特性,为组织工程椎间盘种子细胞的选取提供依据.方法:髓核组织取材于3例脊柱侧凸行前路矫形手术者(年龄11～13岁),依次用0.25%胰蛋白酶和0.2%Ⅱ型胶原酶分离髓核细胞,用含10%胎牛血清(FBS)的F12培养液培养细胞,取传1～7代次细胞进行光镜、电镜检查,观察细胞形态学改变,对细胞计数、二甲基噻唑二苯基四唑溴盐(MTT)摄取进行比较,通过逆转录-聚合酶链反应(RT-PCR)测定细胞的聚集蛋白聚糖(Aggrecan)、Ⅰ型和Ⅱ型胶原蛋白信使RNA(mRNA)的表达情况.结果:体外培养条件下,传3代之前的细胞形态正常,胞浆丰富;传4代起.部分细胞的形态逐渐向长梭形演化.与传1代细胞相比,传2、3代细胞数量增殖无明显减缓(P>0.05),传4代细胞第4天开始生长减慢(P<0.05),传5Ⅰ7代细胞第2天即较转1代细胞数量明显减少(P<0.05).传1Ⅰ3代细胞的MTT摄取吸光度值差异无统计学意义(P>0.05),和传1代相比,传4代具有统计学差异(P<0.05),传5Ⅰ7代的差异更显著(P<0.01).聚集蛋白聚糖和Ⅱ型胶原在传3代之前各代次的mRNA表达量间无统计学差异(P>0.05),和传1代相比,Ⅱ型胶原从第4代起表达量显著下降(P<0.05),聚集蛋白聚糖从第5代起表达量显著下降(P<0.05),而从传5代起髓核软骨样细胞开始表达Ⅰ型胶原:结论:髓核细胞传代后前3代细胞形态良好,增殖能力强,聚集蛋白聚糖和Ⅱ型胶原mRNA表达良好,适合作为组织工程椎间盘的种子细胞.     

Pyruvate-modified perfadex improves lung function after long-term hypothermic storage.

BACKGROUND: Lungs harvested for transplantation are stored while inflated with oxygen, which can serve to support oxidative metabolism. However, strategies aimed at increasing graft metabolism during storage have received little attention. In this study, we added pyruvate to the preservation solution Perfadex and measured the effects on oxidative metabolism and reperfusion lung function. METHODS: Rat lungs were stored for 6 and 24 hours in low-potassium dextran solution at 10 degrees C containing either 5 mmol/liter uniformly carbon-13 (U-(13)C) labeled glucose (Perfadex), 32 mmol/liter 3-(13)C pyruvate (pyruvate), or both (combined). Oxidation of exogenous substrates was measured as the incorporation of (13)C into tricarboxylic acid cycle intermediates by magnetic resonance spectroscopy. Additional groups of lungs with each substrate modification were preserved for 6 or 24 hours and then reperfused. RESULTS: Enrichment of tricarboxylic acid cycle intermediates was low in the Perfadex group (9% at 6 hours and 32% at 24 hours of storage, respectively). In contrast, enrichment was significantly increased in both the pyruvate group (50% and 59%, respectively) and combined group (39% and 54%, respectively) compared with the Perfadex group (p<0.01). Graft function was excellent after 6-hour storage in all groups. All lungs stored for 24 hours exhibited inferior lung function, but oxygenation, pulmonary artery pressures, and airway pressures in the combined group were significantly improved compared with the Perfadex group (p<0.05). CONCLUSIONS: Preservation solution substrate composition influences graft metabolism during storage. The addition of pyruvate to Perfadex increases metabolism during storage and improves reperfusion lung function.     

内镜活检对胃癌组织学分类术前诊断的价值

目的 探讨内镜活检对胃癌组织学分类术前诊断的价值。方法 术前对141例胃癌患的内镜活检标本分别根据Lauren分类和世界卫生组织（WHO）分类判断组织学分类，并与手术标本结果对照。结果 内镜活检对胃癌Lauren分类术前诊断的准确率为76.6%。对肠型胃癌诊断的敏感性和特异性分别为85.4%和80.6%。而对弥漫型胃癌则分别为82.7%和80.3%，在59例术前诊断为肠型胃癌的病例中，18例（30.5%)在手术标本中呈弥漫性行生长，而在75例术前诊断为弥漫型胃癌的病例中，仅6例（8.0%)术后诊断为肠型胃癌，内镜活检对胃癌WHO分类术前诊断的准确率为87.2%，其中对乳头状/管状腺癌，黏液腺癌和印戒细胞癌的敏感性分别为91.9%。33.3%和66.7%。结论 内镜活检对胃癌组织学分类的术前诊断具有较高的临床应用价值。     

Quantification of bone healing. Comparison of QCT, SPA, MRI, and DEXA in dog osteotomies

Four noninvasive imaging modalities were used to quantitatively evaluate and compare tibial osteotomy healing in dogs. Quantitative computed tomography (QCT), magnetic resonance imaging (MRI), single-photon absorptiometry (SPA), and dual-energy x-ray absorptiometry (DEXA) were the four techniques examined. Bilateral tibial osteotomies were performed in 32 dogs divided into four groups. The osteotomies were stabilized with a 2-mm gap using unilateral external skeletal fixation. Dogs were anesthetized, imaged with the four noninvasive techniques, and killed at 2-12 weeks. Invasive techniques were used to determine: 1) the torsional properties of the bone; and 2) the local stiffness properties and calcium content within the bone. The techniques which had the strongest associations with the torsional properties of the osteotomies were QCT, SPA and DEXA. Generally, QCT and SPA had marginally stronger correlations than DEXA; but, overall, there were no differences between the techniques. MRI had the poorest associations with the torsional properties of the osteotomies. Generally, QCT had the strongest correlations with local material properties, such as indentation stiffness and calcium content. SPA had the second strongest correlations with calcium content and had the third strongest correlations with indentation stiffness behind DEXA. DEXA had the third strongest correlations for calcium content. With the exception of some of the correlations with indentation stiffness, MRI had the poorest associations with the local parameters studied.     

Dynamic imaging with lanthanide chelates in normal brain: contrast due to magnetic susceptibility effects

Using a one-dimensional rapid imaging technique, we have found that injection of lanthanide chelates such as Gd(DTPA)2- leads to a significant decrease (50%) in rat brain signal intensity at 1.45 T using T2-weighted pulse sequences; however, no effect of comparable size is observed with T1-weighted pulse sequences. The transient effect and its kinetics were followed with a temporal resolution of between 1 and 8 s. Experiments with different lanthanide chelates show that the observed decrease in signal intensity correlates with the magnetic moment of each agent but not with their longitudinal relaxivity. Three-dimensional chemical-shift resolved experiments demonstrate significant line broadening in brain during infusion with Dy(DTPA)2-. Our results show that the cause of this effect is the difference in susceptibility between the capillaries, containing the contrast agent, and the surrounding tissue. As a result of these susceptibility differences, field gradients are produced in the tissue and diffusion of water through these gradients leads to a loss of spin phase coherence and thus a decrease in signal intensity. We propose this as a new type of contrast agent mechanism in NMR. The effect and its kinetics are likely to be related to important physiological parameters such as cerebral blood volume and cerebral blood flow, and do not depend on a breakdown of the blood-brain barrier as do conventional contrast agent techniques.     

顺丁烯二酸水溶液的热反应动力学

研究了不同温度、浓度条件下，顺丁烯二酸（顺酸）非催化反应网络，即顺酸可生成反丁烯二酸（反酸）和苹果酸，反酸与苹果酸存在可逆反应。建立了该反应网络的动力学模型。测定了不同反应条件下顺酸、反酸和苹果酸浓度随时间变化的规律，据此，动力学参数进行了估值。