颈部内镜手术充CO2和氦气对代谢和血流动力学的影响

目的：通过兔颈部灌注CO2和氦气（He）,检测不同压力和灌注持续时间对动物代谢、血流动力学各项指标的影响。方法：将15只新西兰兔随机分成5组,每组3只,分别为5mmHg（1mmHg=0．133kPa）COz组、10mmHg CO2组、15mmHg CO2组、15mmHg He组及对照组（颈部不充气）。分别在充气前（T0）,充气后45min（T1）、90min（T2）和放气后30min（T3）记录PaCO2、pH、HR、MAP和CVP。结果：5mmHg CO2组各项检测指标均无明显变化;10mmHg CO2组在T1和T2时PaCO2显著升高（P〈0．01）;15mmHg CO2组在T1和T2时Pa CO2、PH和CVP显著升高（均P〈0．01）,T3时仍高于T0（P〈0．01或P〈0.05）。15mmHg He组在T2时CVP显著升高（P〈0．05）,T3时回落到基线水平。各组的HR和MAP在各时间点均无显著变化。结论：在颈部内镜手术中将CO2充气压力控制在10mmHg以下是安全的;当需要更大压力时,应尽可能将压力控制在15mmHg以下,并严格限制充气时间;He由于溶解度低应慎用。     

糖尿病患者白内障超声乳化术后眼血流动力学改变观察

目的 观察超声乳化白内障吸除术对于糖尿病患者眼血流动力学的影响.方法 对比分析30例行超声乳化白内障吸出术的糖尿病患者手术眼与对侧未手术眼以及30例无糖尿病患者行超声乳化白内障吸出术者手术前及术后1d,视网膜中央动脉、中央静脉血流动力学:PSV、EDV、RI、V-max V-min 测量资料.结果 糖尿病患者白内障超声乳化手术术眼术前平均PSV为(9.19±3.17)cm/s,术后为(10.39±3.03)cm/s,二者比较差异有显著性意义(P<0.05);未手术眼初次检查PSV为(9.06±2.67)cm/s,术后复查为(8.60±3.19)cm/s,二者比较差异无显著性意义(P>0.05).无糖尿病患者行白内障超声乳化手术眼术前PSV为(10.13±2.57)cm/s,术后为(10.80±3.33)cm/s,二者比较差异无显著性意义(P>0.05);三组患者视网膜中央静脉最大血流速度V-max在手术前后也观测到如上结果,而EDV、RI、V-min的变化无统计学差异.结论 糖尿病患者行超声乳化白内障吸除术后视网膜中央血管的血流动力学会发生改变.     

提高大鼠心肌梗死后心力衰竭模型存活率的实验研究

目的建立大鼠心肌梗死后心力衰竭模型,并进行评估,以提高存活率和成功率。方法分批对70只SD大鼠行冠状动脉左前降支结扎术,同时设15只假手术组,并计算死亡率。于4周时行血流动力学检查,检测心率(HR)、左心室舒张末压(LVEDP)、左室压力最大上升速率(+dp/dtmax)以及左室压力最大下降速率(-dp/dtmax)。结果4周时模型组HR、+dp/dtmax和-dp/dtmax绝对值均低于假手术组(P<0.05),LVEDP则高于假手术组(P<0.05)。随着手术大鼠例数增多,存活率得到提高(P<0.05)。结论心肌梗死后4周形成心力衰竭模型,通过经口气管插管法、选择结扎冠状动脉分支末梢部位、增加手术操作熟练程度,可提高动物存活率。     

Women and men exhibit different cortical activation patterns during mental rotation tasks

The strongest sex differences on any cognitive task, favoring men, are found for tasks that require the mental rotation of three-dimensional objects. A number of studies have explored functional brain activation during mental rotation tasks, and sex differences have been noted in some. However, in these studies there was a substantial confounding factor because male and female subjects differed in overall performance levels. In contrast, our functional brain activation study examined cortical activation patterns for males and females who did not differ in overall level of performance on three mental rotation tasks. This allowed us to eliminate any confounding influences of overall performance levels. Women exhibited significant bilateral activations in the intraparietal sulcus (IPS) and the superior and inferior parietal lobule, as well as in the inferior temporal gyrus (ITG) and the premotor areas. Men showed significant activation in the right parieto-occitpital sulcus (POS), the left intraparietal sulcus and the left superior parietal lobule (SPL). Both men and women showed activation of the premotor areas but men also showed an additional significant activation of the left motor cortex. No significant activation was found in the inferior temporal gyrus. Our results suggest that there are genuine between-sex differences in cerebral activation patterns during mental rotation activities even when performances are similar. Such differences suggest that the sexes use different strategies in solving mental rotation tasks.     

比较多巴胺与去甲肾上腺素对感染性休克血流动力学和氧代谢的影响

目的比较多巴胺与去甲肾上腺素对感染性休克患者血流动力学和氧代谢的影响。方法44例早期感染性休克患者经过充足的液体复苏使肺动脉楔压(PAWP)维持在1.6～2kPa之间,随机分为多巴胺组(Dopa组)和去甲肾上腺素组(NE组)。分别加用多巴胺或去甲肾上腺素,使平均动脉压(MAP)维持>10.7kPa。分别测定并计算应用多巴胺或去甲肾上腺素前(T0)、用药后1h(T1)、4h(T2)、8h(T3)、16h(T4)、24h(T5)和48h(T6)各个时间点的血流动力学指标[包括心率(HR)、外周血管阻力指数(SVRI)、心脏指数(CI)、肺动脉楔压(PAWP)及平均肺动脉压(MPAP)]和氧和指标[包括氧供指数(DO2I)、氧耗指数(VO2I)及氧摄取率(O2ext)]。结果(1)用药后2组同一时间点的HR、CI相比,NE组显著低于Dopa组(P<0.05);NE组的SVRI明显高于Dopa组(P<0.05)。(2)Dopa组的DO2I比NE组明显增加(P<0.05),NE组的VO2I、O2ext和Dopa组同一时间点相比明显增高(P<0.05)。结论对于早期感染性休克患者,去甲肾上腺素比多巴胺能更好的维持血流动力学稳定,它可以增加脏器灌注,提高O2ext,改善氧代谢。     

左室和双心室起搏对犬心电及血流动力学的影响

目的探讨左室和双心室起搏对QRS波时限（QRSd）及血流动力学的影响。方法12只犬，开胸后于心外膜随机行右室心尖部、左室及双心室起搏，起搏频率为150次／min，起搏稳定15min后测定QRSd、平均肺动脉压（mPAP）、肺毛细血管楔压（PCWP）、心指数（CI）。结果与右室心尖部起搏相比：左室起搏时QRS波时限缩短不明显（P〉0．05），而双心室起搏时QRS波缩短明显（P〈0．05）；左室及双心室起搏时心指数显著增加，两种方式间差异无统计学意义。结论双心室起搏可同步改善心室的电活动及机械活动，而左室起搏不同，没有实现电同步但仍可获得近似于双心室起搏的血流动力学效果。     

Ruptured cerebral aneurysms associated with arterial occlusion

Seven cases of ruptured cerebral aneurysm associated with an occlusion of a large cerebral artery are reported. All seven patients had never suffered from ischemic cerebrovascular disease before the aneurysmal rupture. All nine aneurysms, including the two unruptured ones, arose on the artery serving as an important collateral pathway, and eight of the nine were found in locations where saccular aneurysms are known to occur infrequently. The role of hemodynamic factors in the pathogenesis of these aneurysms is stressed.     

Physiologic-insensitive left ventricular assist predisposes right-sided circulatory failure: a pilot simulation and validation study

Right-sided circulatory failure (RSCF) is a serious complication in 15-30% of patients receiving a left ventricular assist device (LVAD). It is hypothesized that left ventricular support which lacks physiologic properties predisposes to RSCF. An integral computer simulation and experimental validation protocol was performed. The results suggest that with conventional insensitive left ventricular support right-sided circulatory function is compromised, which may form a substrate for the onset or progress of RSCF. Feedback control of the LVAD could provide a means to counter this problem. A control concept for the LVAD which aims to preserve right-sided circulatory function, while supporting peripheral perfusion, is proposed