转hCTLA4Ig树突状细胞诱导T细胞免疫耐受的实验研究

目的　通过逆转录病毒载体将人CTLA4Ig转染DCs ,探讨转人CTLA4Ig(hCTLA4Ig)树突状细胞 (DCsRev)诱导T细胞免疫耐受的可能性。方法　通过重组逆转录病毒将目的基因hCTLA4Ig转染到大鼠骨髓来源的DCs中 ,通过流式细胞检测目的基因hCTLA4Ig表达及DCs表面分子的改变 ;通过混合淋巴细胞反应 (MLR)检测DCsRev抑制T细胞免疫反应的能力。 结果　重组逆转录病毒转染DCs的最大效率为 91 2 5 % ;在功能上 ,DCsRev不但丧失了刺激MLR的能力 ,并且能够强烈抑制MLR中反应T细胞的增殖 ,而且抑制率与加入DCsRev的数量和DCsRev预处理反应T细胞的时间长短有关。具体来说 ,DCsRev数量在 10 3 ～ 10 4之间时 ,抑制率与剂量呈正相关 ,最高为 71 96%。而当DCsRev数量达到 5× 10 4抑制率下降为 5 9 2 %。在 12～ 48h之间 ,随着预处理时间的延长 ,抑制率却不断下降 ,预处理 12h抑制率最高 ,为 99 6%。但不做预处理 ,在反应开始时同时加入DCsRev ,则抑制率明显降低 ,仅为 5 9 2 %。对腹腔注射DCsRev大鼠脾T淋巴细胞体外分析表明 ,DCsRev也能在动物体内诱导耐受 ,但这种免疫耐受状态不能维持终身。结论　通过逆转录病毒载体将人CTLA4Ig转染DCs,不但DCs表面CD86分子被CTLA4Ig有效的封闭 ,并且能够诱导抗原特异性T细胞的免疫耐受     

缩窄性心包炎的外科治疗

报告12例缩窄性心包炎外科治疗的体会，本组病例的特点是病史长，入院前误诊率高（41.6%)，心增厚达0.5-2cm，龟壳样变。结果：12例手术资料随访1-6a，手术疗效满意，认为对诊断明确者应及早手术治疗，尽可能彻底剥脱缩窄的心包是手术疗效的关键。     

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。     

Intracellular Ca2+ suppressed a transient potassium current in hippocampal neurons

The effects of intracellular Ca2+ (Ca2+i) on K+ currents in hippocampal cells were examined using acutely isolated cells obtained from adult guinea pigs. Whole-cell voltage-clamp recordings were carried out in a configuration that allowed a continuous perfusion of the intracellular medium. Recording media were made to block inward currents and allowed selective activation of K(+)-dependent outward currents. Voltage-dependent outward currents consisted of an initial rapidly decaying component followed by a sustained component. The time constant of decay of the transient current was about 25 msec, and previous studies (Numann et al., 1987) showed that the kinetic and pharmacological properties of this current closely resembled the A current recorded in invertebrate neurons (Connor and Stevens, 1971; Thompson, 1982). Intracellular perfusion of hippocampal cells with a solution containing elevated Ca2+ (about 4.5 x 10(-4) M) elicited outward currents at the holding potential (-45 to -55 mV) and produced changes in voltage-dependent K+ currents. The transient outward current (IA) activated by depolarization was suppressed with increases in Ca2+i. Delayed, sustained K+ currents were greatly potentiated. Data also showed that, among the 3 effects elicited by Ca2+i, suppression of IA was most sensitive to Ca2+i elevation. Previous results (Numann et al., 1987) showed that IA had a lower threshold (about -45 mV) than sustained currents (about -40 mV). By using low levels of depolarization (-40 mV), IA can be selectively activated, and the suppressive effect of Ca2+i on IA was confirmed on the kinetically isolated IA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Therapy of human cervical carcinoma with monoclonal antibody-Pseudomonas exotoxin conjugates.

Pseudomonas exotoxin A (PE) linked to the F(ab')2 fragment of 1H10, a murine monoclonal antibody recognizing a carbohydrate epitope of a glycoconjugate expressed on the surface of human cervical carcinoma tumor cells, was evaluated for in vitro and in vivo activity. PE can kill cells by ADP-ribosylating elongation factor 2 thus inhibiting protein synthesis. Disulfide- as well as thioether-linked immunotoxins (1H10-PE) killed cervical carcinoma cells in vitro and were 20-160 times more inhibitory to target than to control cells. Cell killing was antibody mediated as demonstrated by the reduction of 1H10-PE growth inhibition to target CaSki cells by free 1H10 F(ab')2. In addition, a control antibody immunotoxin was nontoxic to CaSki cells. Thioether-linked 1H10-PE administered either i.v. or i.p. suppressed the growth of established solid s.c. cervical carcinoma tumors xenografted in nude mice for over 30 days. Treatment with antibody alone or a control immunotoxin had no significant effect on tumor growth. Administration of immunotoxin i.p. was associated with less toxicity than administration i.v., but i.v. injections were more effective at suppressing the growth of established solid tumors.     

Ischemic rat brain extracts induce human marrow stromal cell growth factor production

Intravenous administration of human bone marrow stromal cells (hMSCs) after middle cerebral artery occlusion (MCAo) in rats provides functional benefit. We tested the hypothesis that these functional benefits are derived in part from hMSC production of growth and trophic factors. Quantitative sandwich enzyme‐linked immunosorbent assay (ELISA) of hMSCs cultured with normal and MCAo brain extracts were performed. hMSCs cultured in supernatant derived from ischemic brain extracts increased production of brain‐derived neurotrophic factor (BDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF). These neurotrophins and angiogenic growth factors increased in a post‐ischemia time‐dependent manner. The hMSC capacity to increase expression of growth and trophic factors may be the key to the benefit provided by transplanted hMSCs in the ischemic brain.     

烹调油烟致大小鼠肺癌的实验研究

[目的]了解烹调油烟（cooking oil fumes，COF）的动物致癌性。[方法]采用动式染毒法给Balb／c小鼠（雌雄各半）吸入COF浓度为9．09、20．65、38．85mg／m^3，染毒1次／1～2d，30min／次，共150次，计8个月；SD大鼠（雌雄各半）吸入COF浓度为6、88、15．06、35．33mg／m^3，染毒1次／2d，30min／次，共191次，计12．5个月。分别制备COF慢性中毒动物模型；两实验均设空白对照组，吸入与实验组相同温度的清洁空气。[结果]COF诱发Balb／c小鼠实验组肺癌总发生率为18、95％（29／153），低、中、高浓度组肺癌发生率分别为15．09％、20、00％和22．00％，与对照组差异均有显著性。但低、中、高三组间差异无显著性（P〉0．05）；COF诱发SD大鼠肺癌总发生率为9、10％（9／99），低、中、高浓度组肺癌发生率分别为6．45％、8．57％、12．12％，高浓度组肺癌发生率高于对照组（P〈0．05）。各性别组间肺癌发生率的差别无显著性（P〉0．05）。[结论]COF可以诱导Balb／c小鼠和SD大鼠肺癌，诱发的肺癌主要为肺腺癌（小鼠28／29，大鼠7／9），余为小细胞肺癌。     

应用皮瓣移植修复足跟部皮肤软组织缺损

目的通过8种不同皮瓣的临床应用,总结足跟部皮肤软组织缺损的修复效果。方法采用了游离足背皮瓣、游离背阔肌皮瓣、游离肩胛皮瓣、桥式胫后动脉岛状皮瓣、桥式携带背阔肌皮瓣或桥式携带肩胛皮瓣、胫后动脉岛状皮瓣、胫后动脉皮支岛状皮瓣、跖底内侧动脉岛状皮瓣,对足跟部皮肤软组织缺损进行修复的临床应用。结果95块皮瓣修复足跟部皮肤软组织缺损,成活93块,成功率为97.9%。随访1～15年,治疗效果满意。结论应用皮瓣移植的方法,才能使足跟部皮肤软组织缺损得到有效的修复。     

成人成骨细胞与珊瑚羟基磷灰石的体外生物相容性

目的：研究成人骨髓成骨细胞与珊瑚羟基磷灰石（carolline hydroxyapatite,CHA)在体外培养条件下的生物相容性。方法：抽取健康成人骨髓组织，置于含体积分数为10％胎牛血清的DMEM培养基中培养，传代后改用含地塞米松、β-甘油磷酸钠和维生素C的条件培养基培养，分为CHA复合细胞组和单纯细胞组，不同时间用倒置相关显微镜，HE染色光镜及扫描电镜观察，MTT法进行细胞增殖测定，并进行细胞微量蛋白含量和碱性磷酸酶的定量检测，结果：成人骨髓成骨细胞体外培养时复合或不复合CHA均生长良好，表现出典型成骨细胞的形态特征和生物学特性，CHA利于细胞的贴附，生长与增殖，并对细胞的功能无不良影响，结论：CHA是较理想的骨组织工程支架材料，成骨细胞复合CHA用于骨缺损的修复，具有广阔的临床应用前景。