Ly49 gene expression in different inbred mouse strains

Mouse natural killer cells express receptors for class IMHC in the form of the Ly49 family of proteins. The Ly49 family contains at least 13 expressed members (A, B, C, D, E, F, G, H, I, J, L, O, and P) and is further subdivided into activating and inhibitory subfamilies based on intracellular and transmembrane characteristics. The level of sequence identity between different members varies dramatically. However, comparison of the extracellular domain has revealed that several of the Ly49 molecules also form “pairs,” where one member is activating and the other is inhibitory. Until recently, most Ly49 molecules described have come from the C57B1/6 strain of inbred mice. Using molecular cloning and immunochemical analysis we have found that different mouse strains express novel Ly49 molecules. Comparison of the allelic forms of some Ly49 molecules has shown that the dividing line between different genes and different alleles is blurred. This project has been funded in whole or in part with federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. NO1-CO-56000. Animal care was provided in accordance with the procedures outlined in A Guide for the Care and Use of Laboratory Animals (National Institutes of Health Publication No. 86-23, 1985). The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. government.     

缺血后处理改善前壁急性心肌梗死患者再灌注心肌长轴的收缩功能

目的：探讨缺血后处理(ischemic postconditioning,IPTC)是否能改善左心室受损的局部或整体长轴的收缩功 能。方法：试验分为PCI组、PCI+IPTC组及对照组。PCI组为前壁急性ST段抬高型心肌梗死患者(ST-segment elevation myocardial infarction,STEMI)患者32例,行首次急诊经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI) 术;PCI+IPTC组为前壁急性STEMI患者28例,行急诊PCI联合IPTC术;对照组为30例,行冠状动脉造影术。采集术 前,术后0.5 h,1 d,3 d,1周,1个月和6个月二维动态超声心动图。对比研究PCI组、PCI+IPTC组与对照组各时间点 局部与整体长轴应变参数。结果：PCI+IPTC组PCI术后1周内左心室梗死节段长轴应变高于PCI组(P<0.05),左心室整 体长轴应变较PCI组有增高趋势,但差异无统计学意义(P>0.05);PCI+IPTC组术后远期左心室局部及整体长轴应变与 PCI组比较,差异均无统计学意义(均P>0.05)。结论：IPTC可改善前壁急性STEMI患者PCI术后早期左心室再灌注心肌 的长轴收缩功能。     

一种四点弯曲单向交变应变细胞加载装置的研制

本文根据细胞动力学对力学因素的响应,设计研制了一种四点弯曲单向交变应变加载装置。通过对Wistar大鼠成骨细胞的试验,以及流式细胞仪（FCM）对细胞DNA分析检测的结果,表明研制是成功的,并可广泛使用于内皮细胞、成纤维细胞、平滑肌细胞、心肌细胞等组织工程和生物医学工程、人机工程学、细胞力学方面的研究。     

Single-channel and whole-cell analysis of ethanol inhibition of NMDA-activated currents in cultured mouse cortical and hippocampal neurons

The effects of 0.1 to 500 mM ethanol on NMDA-activated currents were studied in primary cultures of mouse cortical and hippocampal neurons. In whole-cell recordings the IC₅₀S for inhibition of NMDA-activated currents by ethanol were 129 mM ± 20 mM in hippocampal neurons and 126 ± 18 mM in cortical neurons. In single-channel recordings from excised outside-out patches of cortical neurons, ethanol inhibited total charge per minute with an IC₅₀ of 174 ± 23 mM, which was not significantly different from the IC₅₀S for inhibition of whole-cell current. The reduction in mean open channel lifetime by ethanol was fit by the logistic equation with an apparent IC₅₀ of 340 ± 28 mM. Analysis of single-channel data indicated that ethanol inhibition of NMDA currents did not involve substantial changes in fast closed state kinetics, changes in open channel conductance, or block of the open channel. At the whole-cell IC₅₀, of ethanol, mean open channel lifetime would decrease by 28% and frequency of opening would decline by 31% to account for the reduction in current. Single-channel data were consistent with ethanol being an allosteric modulator of gating which reduces agonist efficacy.     

Strain-dependent effects of cocaine on memory storage improvement induced by post-training physostigmine

Post-training administration of the inhibitor of cholinesterase enzymes, physostigmine, dose-dependently (0.025–0.4 mg/kg) improved retention of an inhibitory avoidance response in C57BL/6 (C57) as well as in DBA/2 (DBA) mice, the latter being more responsive than C57 mice. The effects on retention performance induced by physostigmine in C57 and DBA mice appeared to be due to an effect on memory consolidation. In fact, they were observed when drugs were given at short, but not long, periods of time after training, which is when the memory trace is susceptible to modulation. Moreover, these effects are not to be ascribed to a rewarding or non-specific action of the drugs on retention performance, as the latencies during the retention test of those mice that had not received a footshock during the training were not affected by the post-training drug administration. Post-training administration of cocaine (1–5 mg/kg) dose-dependently improved retention of an inhibitory avoidance response in C57 mice, while impairing it in the DBA strain, thus confirming previous results (Puglisi-Allegra et al. 1994b). Pretreatment with cocaine at ineffective doses as well as at an effective one potentiated the effects of an ineffective as well as of an effective dose of physostigmine in C57 mice, while it antagonized the effects of the inhibitor of cholinesterase enzymes on memory consolidation in DBA mice. The present results indicate that the indirect DA receptor agonist cocaine affects physostigmine action on memory consolidation in an opposite manner in the two inbred strains, pointing to genotype-dependent interaction between cholinergic and dopaminergic activity in memory consolidation.     

Graduated compression stockings in the prevention of deep vein thrombosis in patients with acute myocardial infarction

Venous volume (venous capacity) of the calf is low in patientswith acute myocardial infarction, who also have a high riskof deep vein thrombosis (DVT). The effect of graduated compressionstockings on the venous volume and on the incidence of DVT wastherefore studied in 80 patients aged 70 years and above withacute myocardial infarction. Graduated compression stockingswere randomly fitted to one leg, the other serving as a control,after which the venous volume was measured by strain gauge plethysmography.The incidence of DVT was measured by the ¹²⁵I fibrinogen uptaketest. Venous volume was significantly higher in legs treatedwith graduated compression stockings compared to control legs.DVT developed in eight control legs but not in any leg treatedwith graduated compression stockings (P = 0.003). DVT was alsosignificantly more frequent in women compared to men and themajority of DVT developed in legs with very low venous volumevalues.     

Astrocytes in hemangioblastomas of the central nervous system and their relationship to stromal cells

Summary Thirteen cases of CNS hemangioblastoma were examined with the immunoperoxidase technique for glial fibrillary acidic protein (GEAP) to determine if there were astrocytic elements among the stromal cells of these tumors.In six cases, including two leptomeningeal hemangioblastomas, none of the stromal cells were positive on GFAP stain. Seven cases, however, showed variable presence of GFAP positive cells, including clusters of heavily lipidized cells deep within cerebellar hemangioblastomas. These GFAP positive cells were indestinguishable by other stains from interstitial or stromal cells.Thus, it appears that in at least some hemangioblastomas of the CNS parenchyma, a few or many stromal cells are lipidized astrocytes. All stromal cells, however, cannot be of astrocytic origin, as proposed by Jakobiec et al. (1976), in view of our six cases where no GFAP-positive cells were found in the tumors.It is suggested that cells identified as stromal cells of hemangioblastomas on light microscopy are a heterogeneous group of cells including astrocytic as well as other elements and that they resemble each other on ordinary stains because of the equalizing effect of cell lipidization.     

Effects of heroin,alone or in combination with other drugs,on the locomotor activity in two inbred strains of mice

The locomotor activity of C57B1/6J and DBA/2J mice was studied, under the influences of heroin, amphetamine, strychnine, or ethanol, and of combinations of the opiate with each one of the other drugs. Heroin treatment was followed by the typical running fit in the C57 mice, while the DBA strain was unaffected. Amphetamine enhanced the activity in the C57 strain only. The combination of heroin with amphetamine or ethanol increased the locomotor activity only in the DBA strain, while heroin + strychnine exerted a clear stimulating effect on the activity of the C57 mice. The strychnine + heroin mixture was more toxic than heroin alone when the lethal doses (LD50) were determined in the 2 strains.     

MDR1基因稳定表达的人肝癌多药耐药细胞株的建立

目的 建立多药耐药基因(MDR1)稳定表达的人肝癌Bel-7402耐药细胞株，为应用RNA干扰技术逆转肿瘤多药耐药基因的表达提供实验模型。方法 应用阿霉素(ADM)长期培养筛选建立Bel-7402耐药细胞株，应用MTT法、流式细胞仪(FCM)及逆转录聚合酶链反应(RT—PCR)对该细胞株相关特性(耐药范围、致死剂量、p-糖蛋白功能及其表达阳性率、MDR1基因检测)进行比较研究。结果 经MTT法检测，耐药细胞株耐药性明显增高，FCM检查发现从敏感细胞到耐药细胞，其阿霉素潴留功能由77．7％降至25．1％，P-糖蛋白(P—gp)阳性率由1．4％升高至54．0％，RT-PCR检查显示该细胞中MDR1 mRNA呈高表达。结论 成功建立了稳定表达MDR1基因的人肝癌Bel-7402耐药细胞株，该细胞中P—gp呈高表达，稳定性好。     

白念珠菌耐药株角鲨烯环氧化酶基因的开放读框突变探讨

目的 从特比萘芬作用的靶酶即角鲨烯环氧化酶编码的基因人手，探讨白念珠菌对特比萘芬耐药的可能机制。方法 对3株特比萘芬耐药的白念珠菌菌株，用聚合酶链反应（PCR），扩增其角鲨烯环氧化酶基因的开放读框（ORF），并进行测序。将测序结果与Genbank中序列登录号U69674、D88252白念珠菌进行比较，有无碱基突变，翻译成氨基酸后再进行比较。结果 对所选3株耐药菌株成功地进行了序列测定，序列分析表明，3株菌中，共有5处碱基突变，但无氨基酸发生置换。结论 未发现由基因突变引起的氨基酸置换导致的白念珠菌对特比萘芬耐药。