三磷酸腺苷结合盒运转体A1与颈动脉粥样硬化斑块的关系

目的 探讨三磷酸腺苷结合盒运转体A1(ATP binding cassette transporter A1,ABCA1)在人颈动脉粥样硬化斑块中的表达变化及作用机制.方法 收集24例人颈动脉粥样硬化斑块标本和10例肠系膜动脉标本(对照组),采用RT-PCR测定ABCA1 mRNA和视黄酸X受体α(RXRα)mRNA表达水平,并采用Western Blot检测ABCA1及RXRα的蛋白表达水平.24例人颈动脉粥样硬化斑块标本按病理分级,比较病理组织为Ⅲ级和Ⅰ级动脉粥样硬化组织间ABCA1 mRNA、RXRαmRNA表达水平及蛋白表达水平.结果 颈动脉粥样硬化斑块组的ABCA1 mRNA(0.79±0.04)和RXRα mRNA(0.73±0.04)表达与对照组相比上调,差异有统计学意义(P＜0.05);ABCA1 mRNA与RXRα mRNA增加水平相关(P＜0.05);颈动脉粥样硬化斑块的ABCA1蛋白表达(0.22±0.03)下调水平与对照组(0.53±0.03)相比差异有统计学意义(P＜0.05);Ⅲ级和Ⅰ级动脉硬化斑块ABCA1mRNA、RXRα mRNA及蛋白表达水平差异有统计学意义(P＜0.05).结论 ABCA1及RXRα蛋白表达水平下调可能是进展性动脉粥样硬化损害的关键因素.     

发育期大鼠高热惊厥前后海马γ-氨基丁酸B受体亚基表达的变化

目的：研究高热惊厥(febrile seizures，FS)对发育期大鼠脑内γ-氨基丁酸(γ-aminobutyric acid，GABA)B受体亚基GABABR1与GABARR2蛋白表达的影响。方法：采用热水浴诱导大鼠高热惊厥模型。隔日诱导惊厥1次，共诱导10次，末次惊厥后24h处死大鼠。发育期大鼠随机分为3组：对照组(n＝24)，1次高热处理组(n＝28)，10次高热处理组(n＝40)。高热处理组根据是否出现惊厥再分为1次高热惊厥组(FS1，n＝16)与1次高热未惊厥组(F1，n＝12)，10次高热惊厥组(FS10，n＝15)与10次高热未惊厥组(F10，n＝13)。采用免疫组化方法观察不同次数高热惊厥大鼠脑内GABABR1与GABABR2蛋白表达的变化。结果：FS10大鼠海马齿状回、CAl-CA3区GABABRl和GABABR2蛋白表达明显低于F10、F1、FSl和对照组；F10大鼠上述脑区GABABRl和GABABR2蛋白表达低于F1、FS1和对照组；F1及FS1大鼠与对照组相比差异无显著性；海马各区GABABR1与GABABR2表达的改变大部分平行，但10次高热惊厥后GABABR2在CA1—CA3区下降更明显，而GABABR1在齿状回下降更明显。结论：反复高热惊厥及反复高热均可使发育期大鼠脑内GABABR亚基蛋白表达降低，高热惊厥的影响较单纯高热更为明显，提示GABABR亚单位与发育期大鼠高热惊厥及其脑损伤密切相关。GABABR1与GABABR2改变的不平行可能与受体亚单位组合的可塑性改变有关，这种改变可能导致抑制功能的改变。     

The nature of the head and neck cancer

Summary Squamous cell carcinoma of the head and neck is a disease predominantly of males and is due to a variety of known environmental irritants, notably cigarette smoke. Dietary, viral and immunological factors may also be relevant. Head and neck squamous cancers express epidermal growth factor receptors and some show weak levels of oestrogen receptor activity, but a reliable serum marker of tumour burden remains to be identified. The prognosis is found to be less favourable in females, in those with advanced T stage, in association with multiple node involvement, especially where extracapsular spread is present and where the T4/T8 ratio is elevated. Administration of heterologous blood during therapy may also have an adverse effect on prognosis. Interested clinicians must remember that most cases are preventable. Correspondence to: A.G.D. Maran     

维生素D受体基因多态性与汉族人群慢性牙周炎易感性的关系

目的 探讨维生素D受体(VDR)基因多态性与汉族人群慢性牙周炎(CP)易感性的关系。方法 收集汉族轻、中、重度CP患者共166例及80名无牙周炎对照者的颊黏膜拭子，以Chelex-100法提取DNA，采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法测定VDR BsmI、VDR ApaI和VDR TaqI的基因型，分析组间基因型分布和等位基因频率的差异。结果 轻、中、重度CP患者中VDR ApaI等位基因A携带者明显多于对照组，重度CP与中度CP、重度CP与轻度CP患者间VDR ApaI基因型的分布差异均有统计学意义，中度CP与轻度CP患者间VDR ApaI基因型分布差异无统计学意义，而VDR BsmI、TaqI位点的基因型分布在患者组和对照组间差异无统计学意义。结论 VDR ApaI等位基因A可能与汉族人群CP的易感性有关。     

Effects of stimulation and blockade of dopamine receptor subtypes on the discriminative stimulus properties of cocaine

The involvement of dopamine (DA) receptor subtypes in the behavioral effects of CNS stimulants was studied in rats trained to discriminate occaine from saline. In substitution tests, the stimulus effects of 10mg/kg of this substance generalized tod-amphetamine (0.25–1.0 mg/kg) and the selective D₂ against LY-171555 (0.05–0.25 mg/kg); but not to the D₁ agonist SKF-38393 (5.0–15.0 mg/kg); in combination tests, the D₁ antagonist Sch-23390 (0.0625–0.5 mg/kg) significantly blocked, and the D₂ antagonist spiperone (0.25–0.5 mg/kg) partially blocked the cocaine cue. These data suggest that the involvement of DA systems in the behavioral effects of cocaine is more complex than either D₁ or D₂ receptor activation; for example, the stimulus properties of this substance might involve both D₁ and D₂ receptor activation.Some of these results were presented at the meeting of the Society for Neuroscience, Toronto, 1988     

转化生长因子-β抑制剂Decorin抗眼结膜滤过泡瘢痕形成的实验研究

目的　探讨Decorin抑制结膜下瘢痕形成的作用机制并为临床应用提供理论依据。方法　新西兰大白兔分为Decorin组、磷酸盐缓冲液 (PBS)组、正常对照组。在滤过术后第 7,14,3 0天 ,应用链酶亲和素免疫组织化学法 (SABC法 )检测各组在结膜滤过泡中转化生长因子 - β1(TGF- β1)和转化生长因子 - βⅠ型受体 (TGF - βRⅠ )的含量 ;应用天狼星玫瑰红 -偏振光法检测各组Ⅰ、Ⅲ型胶原的含量。　结果　PBS组结膜滤过泡中TGF - β1、TGF - βRⅠ免疫组化染色和Ⅰ、Ⅲ型胶原染色呈强阳性表达 ,第 3 0天明显比第 7天增强 (P <0 .0 5 ) ;Decorin组结膜滤过泡中TGF - β1、TGF - βRⅠ免疫组化染色和Ⅰ、Ⅲ型胶原染色呈弱阳性表达 ,相同时相点比较 ,Decorin组比PBS组明显呈弱表达 (P <0 .0 1)。Decorin可使滤过泡瘢痕中TGF - β1和TGF - βRⅠ活性降低 ,Ⅰ、Ⅲ型胶原的含量减少。　结论　Decorin可作为抑制滤过泡瘢痕形成的辅助药物     

骨髓细胞移植上调血管内皮生长因子及其受体的表达并改善缺血心脏功能

目的：通过骨髓细胞移植对心肌梗死大鼠模型血管内皮生长因子及其受体表达的影响，探讨骨髓细胞移植改善缺血心脏功能的可能机制。方法：利用左前降支冠状动脉结扎术制备大鼠心肌梗死模型，然后行异体骨髓细胞移植；分别于术后1d，3d，7d，14d和28d取材；利用免疫荧光和RT—PCR技术分析细胞移植对血管内皮生长因子(VEGF)及其受体(Flk一1)表达的影响和移植细胞的分化情况；通过免疫组化计算血管数量；应用血流动力学检测大鼠心脏功能在术后各时间点的变化。结果：VEGF和Flk-1在移植组动物的心肌梗死区残存细胞、梗死周边区细胞以及部分移植细胞内表达。移植组VEGF和Flk-1的mRNA表达明显高于对照组。分别于术后3d和14d达到高峰，以后逐渐减弱。术后7d，14d和28d移植组血管数量较同期对照组明显增加，移植组心脏功能较对照组明显改善。术后14d可在部分移植细胞中检测到心肌细胞或血管内皮细胞特异性蛋白的表达。结论：骨髓细胞移植通过上调移植细胞及受者内源性VEGF和Flk—1的表达，促进血管新生，进而改善缺血心脏功能。     

白细胞介素—2新的功能位点及其中枢镇痛作用

白细胞介素－２（ＩＬ－２）不仅是重要的免疫调节因子，而且还具有重要的中枢调节作用。本实验以钾离子透入引起大鼠甩尾反应为指标，发现侧脑室注射ＩＬ—２能显著提高动物痛阈，并能被纳洛酮所阻断，表示ＩＬ－２的中枢镇痛作用可能与阿片受体有关。利用基因定位突变技术获得的无免疫活性ＩＬ－２实查体仍具有中枢镇痛作用，表明ＩＬ—２分子上发挥镇痛和免疫调节作用的功能位点是相互独立的。纳洛酮能够阻断ＩＬ—２的中枢镇痛作用，而不能影响ＩＬ—２增殖ＣＴＬＬ－２细胞的作用，提示ＩＬ－２发挥镇痛和免疫调节作用可能通过不同的受体途径。ＩＬ－２分子中第４５位Ｔｙｒ残基突变为Ｖａｌ后，虽仍保留了免疫活性，但丧失了镇痛功能，表示４５位Ｔｙｒ残基是ＩＬ—２发挥中枢镇痛功能的关键残基之一。我们推测ＩＬ—２的镇痛功能位点可能在ＩＬ—２分子中第４５位Ｔｙｒ残基附近区域。     

Renal excretion of endothelin in children

Endothelin (ET) is a peptide with profound vasoconstrictive potential. First isolated from porcine endothelial cell supernatant, it is produced also by smooth muscle, epithelial and circulating cells. Besides vasoconstriction, a wide spectrum of biological activities of ET (via activation of membrane receptors) has been described. These include regulation of other hormones and neurotransmitters, cellular growth and proliferation, bronchoconstriction, and, in the kidney, natriuresis and water diuresis. ET exerts its effects mainly in an autocrine and paracrine fashion. A high concentration of ET is found in urine, compared with plasma originating mainly from the kidney itself. In this review we focus on the role of urinary excretion of ET in children. ET excretion was determined under different physiological and pathological conditions. In premature infants and newborns, the daily excretion of ET (corrected for body surface) was higher than in older children; it was constant, and comparable to the values in healthy adults after the age of 2 years. Renal ET excretion correlated positively with urine flow in both healthy and sick children. Conditions with tubular and/or collecting duct cell damage, such as severe hypoxia, hemolytic-uremic syndrome, renal transplantation, diabetes mellitus, chronic renal failure, and contrast media cytotoxicity were characterized by elevated urinary excretion of ET. In conclusion, the renal excretion of ET is influenced by several factors, probably reflecting the intrarenal ET production. ET has a low specificity with regard to renal injury. Received May 7, 1996; received in revised form January 14, 1997; accepted January 17, 1997     

异丙酚对大鼠海马神经元NMDA受体通道电流的影响

目的 研究异丙酚对大鼠海马神经元N-甲基-D-天冬氨酸（NMDA）受体通道电流的影响。方法 体外培养新生Wistar大鼠海马神经元8—12d，采用全细胞膜片钳技术和压力喷射给药方式，钳制电压为-80mV，记录3、48μg∥ml异丙酚对100μmol／LNMDA诱发NMDA受体通道电流的影响；然后用7-氨基丁酸（GABA）受体拮抗剂荷包牡丹碱100μmol／L阻断GABA．受体，观察3、48μg／ml异丙酚对NMDA受体通道电流的影响。结果 3、48μg／ml异丙酚抑制自发兴奋性突触后电流并直接激动GABA．受体，使Cl．内流，产生外向超极化的GABA电流，从而间接抑制NMDA受体通道电流。用荷包牡丹碱100μmol／L阻断GABA．受体后，3、48μg∥ml异丙酚仍可抑制100μmol／LNMDA诱发的NMDA受体通道电流（P〈0．05）。结论 异丙酚通过激活GABA．受体影响NMDA受体通道电流，对NMDA受体通道也有直接抑制作用。