Influence of the Compliance of the Pump Housing and Cannulas of a Paracorporeal Pneumatic Ventricular Assist Device on Transient Pressure Characteristics

Abstract: The dependence of transient pressure characteristics of a ventricular assist device (VAD) on the compliance of its housing and cannulas was investigated in a mock circulation. The peak rate of change of pressure ( dP/dt _max) values was greater in the cannulas than other compartments and was associated with valve closure-induced pressure oscillations. When cannula compliance was increased from 0.0057 to 0.0129 cm³/mm Hg, these values decreased by ˜20%, and outflow cannula pressure oscillation frequency decreased from 17.5 Hz by 35%. This trend was also apparent in the inflow. A VAD housing compliance increase from 0.0162 to 0.0483 cm³/mm Hg caused a dP/dt _max decrease of 30% in both the blood chamber and the outflow cannula. The effect of this change on the inflow was weaker implying that housing absorbs the energy associated with outflow deceleration more effectively than the inflow. These findings suggest that increasing VAD housing and cannulas compliance can improve hydrodynamic performance.     

Human interleukin 4 regulates the phenotype of lymphocytes generated during mixed lymphocyte culture and inhibits the IL-2-induced development of LAK function in normal and leukaemic cells

This study examined the immunoregulatory role of recombinant interleukin 4 (IL-4), also known as B-cell stimulating factor 1, on the generation of cytotoxic effector cells from normal and leukaemic human blood mononuclear cells. When tested on cells from normal individuals, the addition of IL-4 to mixed lymphocyte cultures led to a dose-dependent proliferation of T-helper cells (CD3, 4 positive) with a concomitant decrease in phenotypic and functional cytotoxic T cells and natural killer (NK) cells. IL-4 also inhibited the interleukin-2 (IL-2)-induced generation of lymphokine-activated killer (LAK) activity when added at the beginning of mixed lymphocyte culture. When tested on mature leukaemic NK cells, IL-4 also inhibited the ability of IL-2 to induce LAK function using a short-term culture system. These results show that IL-4 acts on both normal and leukaemic cells and suggests that it acts at more than one level during the development of LAK function.     

联合菌苗抗肿瘤作用的初步探讨

目的 :探讨联合菌苗防治肿瘤的作用。方法采用动物体内实验 ,动物为封闭群KM小鼠 ,菌株为 2 6 0 0 3- 2 1、4 482 4 - 3及 932 0 1- 3,瘤种为S180 。所有实验小鼠接种S180 后 ,按随机对照试验设计分成 5组 ,即三个不同的单价菌苗组、一个联合菌苗组及一个对照组 ,同期观察联合菌苗对S180 增长的影响。结果 :三个不同的单价菌苗组及联合菌苗组的平均瘤重均比对照组低 ,联合菌苗组的平均瘤重比单价菌苗组的更低 ,差异均有高度统计学意义 (P <0 .0 1～ 0 .0 0 1) ;三个不同单价菌苗组的抑瘤率分别为 5 0 .6 %、4 8.3%、4 5 .5 % ,联合菌苗组抑瘤率为 75 .0 %。结论 :实验所选用的菌苗能抑制S180 的增长 ,联合菌苗的效果更好     

腺病毒介导的HSV—tk基因治疗大鼠脑胶质瘤实验研究

目的：带有ＨＳＶ－ｔｋ基因的重组腺病毒（ＡｄＨＣＭＶ－ｔｋ）结合核苷类似物（ＮＡ）治疗大鼠Ｃ６脑胶质瘤。方法：用Ｘ－ｇａｌ染色测定ＡｄＨＣＭＶ－ｌａｃＺ转染大鼠Ｃ６胶质瘤细胞的效率。用ＡｄＨＣＭＶ－ｔｋ／ＡＣＶ、ＧＣＶ离体及活体治疗大鼠Ｃ６胶质瘤。结果：ＡｄＨＣＭＶ－ｌａｃＺ感染Ｃ６细胞效率达１００％，ＡｄＨＣＭＶ－ｔｋ感染Ｃ６细胞，在病毒感染复数为１０００时，ＧＣＶ和ＡＣＶ半致死剂量分别为３μｇ／ｍｌ和２０μｇ／ｍｌ，Ａｄ－ＨＣＭＶ－ｔｋ／ＡＣＶ治疗大鼠Ｃ６胶质瘤模型，大鼠生存期超过９０天，而对照组分别为１７．０±１．６天（生理盐水组）、１４．５±１．３天（ＡｄＨＣＭＶ－ｌａｃＺ组），Ｐ＜０．００１。结论：重组腺病毒对靶细胞感染效率可达１００％，ＡｄＨＣＭＶ－ｔｋ用ＧＣＶ的杀伤Ｃ６胶质瘤细胞比ＡＣＶ强，而ＨＳＶ－ｔｋ／ＡＣＶ用腺病毒介导治疗大鼠脑肿瘤疗效显著。     

胸腰段脊柱脊髓损伤减压与固定相关问题探讨（附166例报告）

目的 对胸腰段脊柱脊髓，马尾神经损伤患者的外科治疗及几种内固定方法的疗效进行探讨。方法 对166例患者的治疗进行回顾分析。该组患者中椎体爆裂性骨折37例，椎体压缩骨折超二分之一109例，椎体骨折脱位14例，多节段或跳跃骨折6例，脊髓损伤按Frankel分级，A级59例，B级46例，C级42例，D级19例，治疗采用后路减压复位122例，前路减压复位，髂骨植骨融合44例。结果 术后123例获3-18个月随访，随访患者中随4例RF钉断裂，5例Harrington上钩脱落，6例棍断裂，其余患者内固定稳固，脊髓，马尾神经恢复，除35例仍为A级外，余脊髓神经功能恢复1-3个级别。结论 各种不同内固定可保持或增强脊柱的稳定，胸腰段脊柱脊髓损伤的外科治疗应根据骨折类型，脊髓及马尾神经损伤程度选择手术入路及内固定材料。     

颈丛阻滞、硬膜外阻滞下甲状腺手术应激反应的比较

目的 :比较颈丛阻滞、硬膜外阻滞下甲状腺手术应激反应的大小。方法 :选择ASAⅠ～Ⅱ级 ,女性 ,甲状腺手术患者 30例 ,年龄 2 2～ 5 5岁 ,术前无呼吸、循环和内分泌疾病 ,随机分为颈丛阻滞组 (颈丛组 ) 15例 ,硬膜外阻滞组(硬膜外组 ) 15例 ;颈丛阻滞选用 0 .8%利多卡因和 0 .2 5 %布比卡因混合液 ,以C4一点法行双侧深浅丛阻滞 ;硬膜外阻滞选用 1.3%利多卡因和 0 .15 %丁卡因混合液 ,穿刺点选择C4～ 5或C5～ 6间隙 ,采用侧卧位直入法 ,并向头置管 3cm ;分别测定并记录麻醉前、麻醉后 2 0min、切皮、分上极、切腺体和术毕共六个时点的血糖、血压和心率的变化。结果 :两组病例各时点血糖均逐步上升 ,于分上极、切腺体和术毕血糖值与麻醉前比较有显著性差异 (P <0 .0 1) ;硬膜外组只在分上极时SBP与麻醉前比较有差异外 (P <0 .0 5 ) ,而颈丛组在分上极、切腺体时DBP与麻醉前比较有差异 (P <0 .0 5 ) ,SBP、MAP与麻醉前比较有显著性差异 (P <0 .0 1)。结论 :本研究表明颈丛阻滞、硬膜外阻滞均不能完全抑制甲状腺手术的应激反应 ,在稳定甲状腺手术循环功能方面硬膜外阻滞优于颈丛阻滞     

青年急性冠脉综合征冠脉造特点及随访

目的:探讨青年急性冠状动脉综合征(ACS)冠状动脉(冠状)造影特点及其与远期心脏事件的关系。方法:比较青年ACS与老年ACS患者冠脉病变程度、范围,并进行心脏事件随访。结果:78例青年ACS患者有冠脉病变74例(94.9％),单支病变46例(58.9％);171例老年ACS患者有冠脉病变166例(97.1％),单支病变41例(23.9％)。平均随访9个月,青年ACS患者发生心脏事件者10例(12.8％),其中心绞痛再入院6例(7.7％);老年ACS患者发生心脏事件者47例(27.5％),其中心绞痛再入院30例(17.5％),两组比较差异有显著性(P<0.05)。结论:ACS患者冠状动脉粥样硬化青年时期之前已经发生,ACS预后与冠脉病变程度和年龄呈正相关。