Flow-independent angiography for peripheral vascular disease: Initial in-vivo results

Flow-independent angiography (FIA), an approach that isolates arterial blood using MR relaxation characteristics rather than flow effects, was evaluated for application in peripheral vascular disease (PVD). First, pilot studies were conducted in which FIA coronal projection images were obtained from controls and symptomatic patients with PVD to assess clinical utility. All control images corresponded to the expected leg arterial anatomy with little interference from deep veins (one of five) and muscle (zero of five). Superficial venous signal was less well suppressed in comparison to deep veins (four of five). Images of symptomatic patients were less consistent with difficulty suppressing muscle and deep venous signal in some cases and edema when present. We then compared T2 values for muscle (T2_m, tibialis anterior), arterial blood (femoral and popliteal arteries), and venous blood (femoral, popliteal, and saphenous veins) in controls (n = 8) and symptomatic patients with intermittent claudication (n = 5) or ischemic rest pain (n = 7). Changes in T2 measurements of various tissues accounted for poorer contrast in symptomatic patients. Patients with ischemic rest pain had significantly higher T2_m compared with controls (T2_m = 39.3 ± 2.1 (1 standard error of the mean [SEM]) versus 30.9 ± .4, P < .01). For all measurements, other than saphenous vein, variances were greater in symptomatic patients. To realize the inherent advantages of FIA for this clinical application, additional work on suppression of signals from muscle, veins, and edema is required. One promising approach involves shifting from projection images to three-dimensional acquisitions for improved tissue suppression.     

面部瘢痕整形手术后胶布减张治疗疗效观察

目的:探讨使用免缝胶布对伤口减张制动的方法和治疗效果。方法:对62例面部瘢痕或痣切除手术患者,随机分组,45例为治疗组,术后5天拆线,拆线当天开始使用免缝胶布。胶布垂直跨越伤口线粘贴,使创缘处于无张力状态。17例为对照组,未使用免缝胶布。术后6个月对瘢痕进行临床评分,治疗组与对照组对比,统计分析。结果:62例患者伤口均一期愈合,治疗组37位(82%)、对照组4位(23%)患者瘢痕恢复至成熟期,没有痒或刺痛的主观症状,瘢痕颜色淡、平坦、质地软;治疗组5位(11.1%)、对照组13位(76.5%)患者瘢痕增宽,有痒或刺痛的症状,瘢痕颜色红,突出皮面。结论:免缝胶布可以有效地减轻伤口两侧张力,减少瘢痕增生,是一种瘢痕术后重要的辅助治疗。     

高氧液对家兔心肌缺血再灌注损伤的保护作用

目的：观察高氧液对家兔心肌缺血再灌注损伤的保护作用。方法：结扎兔冠状动脉左室支段，40min后解除结扎，制成心肌急性缺血再灌注模型。于缺血前10min、再灌注前10min，静滴平衡盐液（对照组）、高氧平衡盐液（高氧液组），观察在急性缺血及再灌注状态下心电图、血浆肌酸磷酸激酶（CK）、丙二醛（MDA）和超氧化物歧化酶（SOD）的变化。结果：高氧平衡盐液能使抬高的心电图S－T段明显下降，缺血再灌注心肌CK活性明显降低；并能保护SOD的活性，降低脂质过氧化反应代谢产物MDA的含量。结论：高氧平衡盐液对家兔在体心肌缺血再灌注损伤具有保护作用。     

急性胰腺炎与内皮素、一氧化氮和氧自由基关系研究

目的　研究急性胰腺炎 (AP)与内皮素 (ET)、一氧化氮 (NO)和氧自由基关系。方法　急性胰腺炎 71例 ,应用放射免疫分析法测定血浆ET、NO和超氧化物歧化酶 (SOD) ,并与健康体检者 15例作对照。结果　急性胰腺炎血浆ET、NO明显升高 ,而SOD明显降低 ,与健康对照组比较差异显著 (P <0 0 1) ;且重症胰腺炎的ET和NO增高、SOD降低尤为明显 ,与轻症胰腺炎相比较有统计学意义 (P <0 0 1)。结论　血浆的ET、NO和SOD异常消长在急性胰腺炎发生、发展过程中具有重要作用。     

SP-C对重组肺表面活性物质活性的影响

目的 探讨不同浓度的肺表面活性物质(PS)相关蛋白C(SP-C)与合成脂质构成的重组PS活性的变化。方法 从新鲜猪肺的灌洗液中提取PS,从PS中分离出SP-C。将二棕榈酰磷脂酰胆碱、二油酰磷脂酰胆碱和棕榈酰油酰磷脂酰甘油按60:20:20的重量比混合,即为合成脂质(SL),将SP-C按1％、2％、3％(与脂质的重量比)加入SL中,制成三种重组PS:RS-1、RS-2和RS-3。将上述物质溶于生理盐水中即为实验液体。用气泡型表面张力计测定各实验液体的表面张力。将PS缺如的未成熟胎兔随机分为4组:PS、SL、RS-3和对照组。分别向PS、SL和RS-3组气道内注入PS、SL、RS-3液;对照组未注入任何物质。然后进行人工通气,通气后5、10、15、20min测定各组潮气量。结果 PS的最小表面张力(γmin)为(0.9±0.3)mN/m,SL的γmin为(22.6±1.3)mN/m,明显高于PS(P<0.01);随SP-C浓度的增加γmin逐渐降低,RS-3的γmin降至(0.7±0.1)mN/m(与PS相比,P>0.05)。通气20min时,PS组、RS-3动物的潮气量分别达到(25±7)ml/kg、(25±4)ml/kg,明显高于对照组和SL组(P<0.01)。结论 不含SP-C的合成脂质表面活性低,加入SP-C后构成的重组PS表面活性明显增强。     

琥珀胆碱和罗库溴铵对全麻诱导期氧供需平衡的影响

目的观察全麻诱导期琥珀胆碱和罗库溴铵对机体氧供需平衡的影响。方法60~70岁全麻手术患者30例,ASAⅠ~Ⅱ级,随机均分为三组:琥珀胆碱组(S组),罗库溴铵组(R组)和对照组(C组),每组10例。右颈内静脉穿刺置管至右心房,分别于麻醉前(T0)、给肌松药前(T1)、给肌松药后1 min(T2)、2 min(T3)、3 min(T4)和5 min(T5)抽右心房血,测定右心房血氧饱和度(RASVO2)、乳酸(Lac)和右心房血氧分压(RAPVO2)。结果三组患者RASVO2、Lac、RAPVO2在相应时点差异无显著意义。与T1相比,S组RASVO2在T2、T3、T4时点明显升高(P<0.05),Lac在T2、T3、T4、T5时点亦明显升高(P<0.05),R组T2时点RASVO2明显升高(P<0.05),而Lac无明显变化。结论琥珀胆碱和罗库溴铵全麻诱导期均可减少机体氧耗量,但琥珀胆碱可引起无氧代谢增加,组织氧供需失衡。     

In vitro determination of lung airway compliance in small animals

An in vitro method for obtaining pressure/volume curves from the lungs of small animals is described. The excised lungs were inflated and deflated with saline or air by a motor-driven syringe controlled by a microcomputer. The computer was programmed to display the curves in real time, correcting when necessary for the compressibility of air in the system. Volume compliance (K=dV/dP×1/V) was calculated by differentiating a polynomial fitted to the measured pressure/volume points. Repeatable curves were obtained from mice aged 24h (body weight 1·3±0·14g (SD), residual lung volume 8·43±1·5 μl (SD). A nonlinear decrease in differential compliance (K=dV/dP×1/V) with increasing strain was observed while the ratio K_saline/K_air increased from 2·5 to 10 over the range of strains investigated (ε=1–5). The relative surface tension (calculated from the difference between the pressures required to inflate the air and saline-filled organs to a given volume) increased exponentially with increasing volume. We conclude that it is now possible to obtain reproducible pressure/volume curves for lungs with a residual volume of less than 10 μl, from animals weighing approximately 1·5 g and, from these curves, estimate airway compliance and surface tension.     

Dorsal root ganglia cocultured with macrophages: an in vitro model to study experimental demyelination

The present investigation introduces an in vitro model to study macrophage properties during demyelination. Rat dorsal root ganglia (DRG) were cultured for obtaining myelinated peripheral nerve fibers. These cultures were exposed to non-resident macrophages. In untreated control cultures, there was no indication of myelin removal by the added macrophages. DRG were exposed to enzymatically generated oxygen radicals using the xanthin/xanthin oxidase or the glucose/glucose oxidase system. Assessment of Schwann cell viability and ultrastructural morphology revealed different patterns of cell cytotoxicity and morphological changes in different experiments. High concentrations caused complete tissue necrosis of the DRG, while low concentrations did not affect either cell viability or ultrastructural morphology. Under intermediate experimental conditions, oxygen radicals caused non-lethal Schwann cell damage leading to Schwann cell retraction and myelin sheath rejection. Myelin lamellae were disrupted and decompacted. These changes were followed by a selective macrophage attack on myelin sheats, resulting in demyelination. Axons, Schwann cells and sensory ganglion cells survived this attack. The specificity of the oxygen radical effects was tested in experiments using the oxygen radical scavengers catalase and superoxide dismutase. Catalase prevented the described effects on cell morphology and subsequently blocked demyelination by non-resident macrophages.Supported by a grant from the Deutsche Forschungsgemeinschaft (DFG) (Br 1274/1-1)     

非体外循环冠状动脉搭桥手术的麻醉方法及血液动力学和氧代谢的变化

目的 观察非体外循环冠状动脉搭桥手术的麻醉方法、术中病人血液动力学和氧代谢的变化以及术后病人的早期.非体外循环冠状动脉搭桥手术闰人20例，麻醉用咪唑安定0.1-0.2mg/kg、芬太尼15－30μg/kg及0.5%-2%的吸入麻醉药等，在切皮前、开心包后、心脏操作中、操作完成后10min及术毕观察血液动力学指标及脑氧饱和度，同时采集桡动脉和肺动脉血，测定血气及动脉血乳酸（ABL），计算氧供DO2）、氧耗（VO2）和氧摄取率（ERO2）。术后早期观察术后拔除气管插管、ICU停留及术后住院时间、并发症及死亡等情况。结果 心脏操作中MAP、SV、SI下降，HR、CVP升高，MAP下降以搭回旋支时最明显（P＜0.01），HR升高以搭右冠时最明显（P＜0.01）；心脏操作中DO2降低（P＜0.05），VO2无变化，ERO2升高（P＜0.01）；操作后DO2、ERO2恢复至操作前水平；操作后ABL升高（P＜0.01）。结论 本组麻醉方法使病人完全度过非体外循环搭桥术，在心脏操作期易出现血压、每搏量、心指数下降，伴心率、静脉压升高，但时间短暂无严重后果，氧代谢紊乱及缺氧程度较轻。