庆大霉素对豚鼠前庭上皮IGF-1及其受体表达的影响

目的：研究庆大霉素对豚鼠前庭上皮胰岛素样生长因子-1（insulin-like growth factor-1，IGF-1）及其受体（insulin-like growth factor-1 receptor，EGF-1R）表达的影响，并探讨其生物学特性。方法：采用免疫组织细胞化学方法，以抗IGF-1及IGF-1R抗体为标记物，检测庆大霉素损伤后豚鼠前庭上皮自发修复期IGF-1及IGF-1R的表达变化和分布特点；采用Brdu体内标记和抗Brdu抗体免疫组化染色，检测庆大霉素损伤后豚鼠前庭上皮增殖的变化。结果：IGF-1及IGF-1R在正常成年豚鼠前庭上皮细胞中有低水平表达，庆大霉素损伤后，其表达增多。在1d组IGF-1及IGF-1R表达最强，其后逐渐减少。在正常对照组中无Brdu阳性细胞。各实验组均观察到Brdu阳性细胞，7d组最多。结论：庆大霉素损伤后，豚鼠前庭上皮IGF-1及IGF-1R表达增强，其时程变化与细胞增殖活动密切相关。IGF-1在豚鼠前庭上皮损伤后的细胞增殖中可能起重要信号转导作用。     

分瓶法测定果蝇吸入麻醉药半数麻醉有效浓度

目的　建立测定果蝇吸入麻醉药半数麻醉有效浓度 (ED50 )的方法学。方法　在 11个 32 5ml的三角烧瓶中各放入 30只雄性果蝇 ,分别加入不同容量的异氟醚标准气 ,使 11个烧瓶中异氟醚浓度分布在零效应浓度与百分之百效应浓度之间。以果蝇失去附壁及运动能力为标准计算各瓶中被麻醉果蝇数 ,用正规法计算出ED50 。结果　 11次实验在 2 5及 5 0min时的量 -效关系曲线均呈S形 ,用各自的对数浓度与概率单位作图都呈直线相关 ,相关系数分别为 0 .972± 0 .0 14和 0 .971± 0 .0 2 5 ,ED50 值分别为 (0 .5 1± 0 .0 6 8) %和 (0 .4 7± 0 .0 85 ) % ,变异系数分别为 13.3%和 18.0 %。结论　本法稳定性较好 ,实用可行     

螺旋CT双期增强扫描与病灶延迟期扫描在肝癌诊断中的应用

目的：研究螺旋CT动脉期、门脉期及病灶延迟期扫描在肝癌诊断中的应用，以进一步选择理想的扫描时期和方案。方法：对48例肝细胞性肝癌患者行平扫及增强扫描，造影剂注射速率为3ml/s，然后开始动脉期、门脉期及病灶延迟期扫描。统计各期的病灶检出数，观察病灶在不同时期的特征。结果：动脉期、门脉期及病灶延迟期的病灶检出率分别为91.9％、76.9％、78.8％，动脉期和门脉期、病灶延迟期之间均有显著差异，而门脉期和病灶延迟期之间无差异。结论：在肝癌的检出方面动脉期价值最大，而门脉期和延迟期之间无差异。双期扫描（动脉期加门脉期）可作为肝癌CT诊断的常规技术，对不典型病例，病灶延迟期很有必要，有助于病灶的定性。     

β-胡萝卜素立体异构体对环磷酰胺处理小鼠免疫功能的比较研究

就β-胡萝卜素立体异构体对环磷酰胺处理小鼠的免疫功能影响进行了比较研究。结果显示β-胡萝卜素立体异构体对外磷酰胺造成的免疫功能低下具有不同程度的改善作用，提高胸腺和脾脏指数，增强脾脏细胞对刀豆素A（ConA）的反应性和NK活性，血清溶菌酶含量也有所增加。综合各项指标，9-顺式和全反式混合物的作用最明显，提示一定浓度的9-顺式对于提高β-胡萝卜素对机体的总体作用是有一定意义的。     

Plasmid DNA encoding transforming growth factor-beta1 suppresses chronic disease in a streptococcal cell wall-induced arthritis model.

Transforming growth factor beta is a potent immunomodulator with both pro- and antiinflammatory activities. Based on its immunosuppressive actions, exogenous TGF-beta has been shown to inhibit autoimmune and chronic inflammatory diseases. To further explore the potential therapeutic role of TGF-beta, we administered a plasmid DNA encoding human TGF-beta1 intramuscularly to rats with streptococcal cell wall-induced arthritis. A single dose of 300 microg plasmid DNA encoding TGF-beta1, but not vector DNA, administered at the peak of the acute phase profoundly suppressed the subsequent evolution of chronic erosive disease typified by disabling joint swelling and deformity (articular index = 8.17+/-0. 17 vs. 1.25+/-0.76, n = 6, day 26, P < 0.01). Moreover, delivery of the TGF-beta1 DNA even as the chronic phase commenced virtually eliminated subsequent inflammation and arthritis. Both radiologic and histopathologic as well as molecular evidence supported the marked inhibitory effect of TGF-beta1 DNA on synovial pathology, with decreases in the inflammatory cell infiltration, pannus formation, cartilage and bone destruction, and the expression of proinflammatory cytokines that characterize this model. Increases in TGF-beta1 protein were detected in the circulation of TGF-beta1 DNA-treated animals, consistent with the observed therapeutic effects being TGF-beta1 dependent. These observations provide the first evidence that gene transfer of plasmid DNA encoding TGF-beta1 provides a mechanism to deliver this potent cytokine that effectively suppresses ongoing inflammatory pathology in arthritis.     

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。     

浅低温心脏不停搏心内手术对心肌保护效果的比较

目的:探讨浅低温体外循环(CPB)心脏搏动中心内直视手术对心肌保护的效果.方法:40例患者随机分为观察组(浅低温心不停搏组)和对照组(中低温心停搏组).分别在术前、转机、停机及术后6 h、12 h、24 h、48 h、72 h,取冠状静脉窦或中心静脉血样,测定血气分析及血清中肌酸磷酸激酶(CK)及其同功酶(CK-MB)、天门冬氨酸氨基转换酶(AST)、乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)的含量.并取心房间隔肌观察心肌含水量及心肌超微结构的改变.临床观察CPB时间、脱机、呼吸支持、多巴胺应用、严重心律失常和血红蛋白尿等指标.结果:冠脉循环血气、电解质、酸碱水平与体循环的组内组间对比基本一致.CK、CK-MB、AST、LDH两组在CPB和术后均有增加,且以对照组升高显著,与观察组相同时点相比,差异均有显著性(P＜0.01).对照组术后MDA明显升高,SOD明显降低(P＜0.01),而观察组变化不大.心肌含水量和超微结构观察,对照组变化显著,而观察组轻微改变.临床指标观察,观察组优于对照组.结论:浅低温体外循环心脏不停搏心内直视手术对心肌损伤很轻,有很好的心肌保护效果.