Interactions between peripheral blood CD8 T lymphocytes and intestinal epithelial cells (iEC)

Intestinal intraepithelial lymphocytes (iIEL) are primarily CD8 cells and most of them have a CD28^? phenotype, the phenotype of effector cytotoxic T cells. We asked whether the predominance of CD8⁺ CD28^? T cells in the gut may result from peripheral blood T cells preferentially migrating to the iIEL compartment and adhering to iEC. Compared with CD4 cells, adhesion of resting CD8⁺ T cells to iEC cell lines was significantly higher. Adhesion could be blocked with a MoAb to gp180, a molecule expressed on iEC which is known to interact with CD8/lck. No significant difference in the level of adhesion was observed between CD8⁺ CD28⁺ and CD8⁺ CD28^? T cells. Thus CD8 cells may preferentially migrate to the iIEL compartment, but loss of CD28 expression could occur in situ after migration. Consistent with this hypothesis, the CD8⁺ CD28^? cells became enriched after co-culturing T cells with iEC cell lines and primary iEC. Induction of the CD8⁺ CD28^? phenotype in cord blood and adult T cells was observed in co-cultures with iEC and also with mitogens and superantigens. In the latter case, CD28 down-modulation was seen specifically in the Vβ subset targeted by the superantigen, indicating that loss of CD28 expression is a direct result of T cell receptor (TCR)-mediated stimulation. The combined results suggest that CD8⁺ CD28^? T cells are antigen experienced T cells, and that they may have a survival advantage in the presence of gut epithelial cells in vitro. This may contribute to the predominance of CD8⁺ CD28^? T cells in the iIEL compartment.     

实验性骨折愈合中骨吸收活动的超微结构观察

将50只家兔造成实验性桡骨骨折,分批取骨痂标本,用光镜和电子显微镜观察表明,在骨折愈合过程中,破骨细胞是骨吸收的主要执行者,巨噬细胞能吞噬死骨,但不能吸收骨质。     

小儿乙状结肠冗长症病理特点分析

目的 探讨小儿乙状结肠冗长症的病理特点，以提高对该症病理特点的认识。方法 分析我科1993～2002年间经手术治疗12例小儿乙状结肠冗长症的临床病理资料。结果 小儿乙状结肠冗长症病理特点与先天性巨结肠同源病相似。主要表现为乙状结肠肠壁肥厚，部分肌纤维变性。结肠黏膜萎缩，黏膜下充血水肿；肌间神经丛减少，均可见神经节细胞发育幼稚，且数量减少或体积变小，呈固缩或空泡变性。结论 小儿乙状结肠冗长症大多有肠神经元发育异常。     

阻塞型睡眠呼吸暂停低通气综合征患者血管活性肠肽与睡眠质量的关系

为明确阻塞型睡眠呼吸暂停低通气综合征 (OSAHS)患者清醒及不同睡眠期血中血管活性肠肽 (VIP)质量浓度与睡眠质量之间的关系 ,以 1 2例OSAHS患者为研究对象 ,在桡动脉内留置导管监测血压 ,同步进行夜间多导睡眠仪连续记录 ,并分别于睡前清醒时、非快动眼 (NREM)睡眠期、快动眼 (REM )睡眠期及清晨从桡动脉留置的导管内抽取血标本 ,采用放免分析法检测VIP。结果 :1 )睡前清醒时及清晨血VIP质量浓度与总睡眠时间和记录时间之比(TST/TRT ,睡眠效率 )成正相关 (r =0 .5 91 ,P <0 .0 5 ) ,与醒觉时间和记录时间之比 (Arousal/TRT)成负相关 (r =-0 .5 86,P <0 .0 5 ) ;以睡前清醒时作基础值 ,NREM期血VIP质量浓度的变化与快波睡眠和总睡眠时间之比 (Ⅰ +Ⅱ /TST)成负相关 (r=-0 .65 6,P <0 .0 5 ) ,与快动眼睡眠时间和总睡眠时间之比 (REM/TST)成正相关 (r =0 .70 5 ,P <0 .0 1 ) ,REM期血VIP质量浓度的变化与REM/TST成正相关 (r=0 .60 9,P <0 .0 5 ) ;2 )OSAHS患者清醒与不同睡眠期血中VIP质量浓度与最长呼吸暂停时间和睡眠呼吸暂停指数 (AHI)成正相关 ,与血氧的有关指标无相关性。提示 :VIP可能参与OSAHS患者睡眠的调节     

乳液聚合型品红成色剂的应用性能

测试了3种新型L-品红成色剂的应用性能。结果表明：与母体品红成色剂相比，L-品红成色剂能显著地减少在蓝光区的有害吸收；与工业用油溶性品红成色剂Ns相比，L-品红成色剂的一些照相性能更加优越。     

实验小鼠肠道正常菌群

在动物肠道中栖息的细菌，构成了肠道正常菌群。实验动物的质量与肠道菌群的状态有着十分密切的联系，肠道菌群平衡状态在维持动物机体的生理状态、正常功能，以及抵抗外袭菌方面起着重要的作用。小鼠肠道中，每克肠内容物含有上亿个菌体，可分为10～15个属，上百个种。肠道正常菌群的主要菌属有双歧杆菌、拟杆菌(类杆菌)、肠球菌、乳杆菌、梭杆菌、真杆菌。不同品系的小鼠之间，各种菌的数量有所不同。本文简要介绍了近年来对小鼠肠道正常菌群的研究进展。     

褪黑素对结肠黏膜上皮细胞氧化应激的影响

目的 探讨褪黑素对大鼠结肠黏膜上皮细胞氧化应激的影响。方法 在分离培养正常大鼠结肠黏膜上皮细胞基础上，利用FeSO4 H2O2产生*OH攻击制备结肠黏膜细胞氧化损伤模型，同时预先加入褪黑素并观察损伤减轻程度。实验设正常对照组、模型对照组、5-氨基水杨酸给药组(0.1mmol／L)，褪黑素给药组(0．01、0．1、l.0mmol／L)。培养一定时间后，取上清测乳酸脱氢酶(LDH)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSHPx)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、一氧化氮(NO)和黏液含量。结果 模型组大鼠结肠黏膜上皮细胞：MDA、LDH和NO水平增高，CAT、GSHPX、SOD和黏液含量减少。不同剂量褪黑素呈剂量依赖性的减少LDH释放，抑制MDA和NO的形成，恢复黏液、CAT、GSHPX及SOD水平。结论 褪黑素对大鼠结肠黏膜氧化损伤具有保护作用。     

锰、铁、锌、铜4种微量元素对芍药生长和芍药苷含量的影响

目的:研究锰、铁、锌、铜4种元素对二、三年生芍药生长的影响.方法:采用完全随机区组,测定施用各微量元素后芍药产量等生理指标和质量指标芍药苷的变化,并用原子吸收分光光度法测定各元素在芍药根、茎、叶及土壤中的含量.结果与结论:锰、铁、锌、铜在一定水平下能显著促进芍药的生长并能提高根中芍药苷的含量,但施用过多会产生生长抑制,除锌外其他元素均不在根中积累.     

小肠内固定术治疗粘连性肠梗阻

目的评价小肠内固定术治疗粘连性肠梗阻的疗效。方法回顾性分析28例粘连性肠梗阻行小肠内固定术患者的临床资料。结果28例患者中有5例发生切口感染,无手术死亡和小肠瘘发生。其中25例患者平均随访23.6个月,1例肠梗阻复发,保守治疗后好转。结论小肠内固定术是治疗预防粘连性肠梗阻可行、有效的方法,但需要注意手术操作细节。     

Detailed Analysis of Mucosal Restoration of the Small Intestine After the Cavitary Two-Layer Cold Storage Method

Small bowel transplantation (SBT) is associated with a high incidence of infectious complications because of ischemia/reperfusion (I/R) mucosal injury concomitant with potent immunosuppression. In this study, we evaluated whether the cavitary two-layer method (cTLM) could reduce I/R injury and allow early mucosal restoration, particularly after prolonged preservation and transplantation. Canine heterotopic segmental SBT was performed immediately without preservation (group 1), after 24-h preservation in UW solution (group 2) or by the cTLM (group 3). The graft samples were taken 1 h after reperfusion and on days 1, 4 and 7. We assessed graft mucosa with detailed microscopic and electromicroscopic analyses. In Group 3, histological injury and cell apoptosis after transplantation were significantly alleviated and rapidly recovered to a similar level of group 1. The mucosal restoration was morphologically completed within 4 days. In contrast, in group 2, more pronounced mucosal injury and delayed recovery were noted. Crypt cell proliferation activity was well maintained in groups 1 and 3 throughout the experimental period. Our ultrastructural analysis suggested that mitochondrial integrity achieved by the cTLM was a basal mechanism under the prompt mucosal restoration. The cTLM could reduce I/R injury, facilitate mucosal regeneration and restore the nearly normal structure early after SBT.