部分背根切断对备用背根节NT-3表达的影响

目的　探讨部分去背根后备用背根节 (L6 )各类细胞NT 3及其mRNA的含量变化。　方法　对成年雄性猫行单侧部分背根切断术 (切除一侧L1 ～L5,L7～S2 DRG ,保留L6 为备用根 )。取正常组一侧和术后 3d及 7d组手术侧的L6 DRG制作 2 0 μm厚冰冻切片 ,分别用NT 3抗体及NT 3cRNA探针行免疫组织化学及原位杂交染色。观察NT 3及其mRNA在DRG各类细胞的分布 ,测定NT 3及其mRNA在神经元和卫星细胞的光密度值 ,所得数据用q检验进行统计分析。　结果　部分去背根后 ,各时相备用背根节大神经元内NT 3的光密度值较正常者进行性减少 ,(P <0 0 5 ) ,而NT 3mRNA的光密度值术后 3d减少 ,7d回升至近正常者水平。比较之 ,小神经元和卫星细胞NT 3及其mRNA的光密度值进行性增多 (P <0 0 5 )。　结论　部分背根切断对备用背根节各类细胞NT 3表达的影响不同 ,其功能意义可能与NT 3参与脊髓Ⅱ板层可塑性有关     

甲氨喋呤对胶原诱导性关节炎大鼠滑膜骨桥蛋白和整合素αVβ3表达的影响

目的 探讨甲氨喋呤对胶原诱导性关节炎(collagen-induced arthritis,CIA)大鼠滑膜骨桥蛋白(osteopontin,OPN)及其受体整合素αvβ3表达的影响及其作用机制.方法 建立CIA大鼠模型,分为模型组和甲氨喋呤(MTX)组,后者用MTX进行干预治疗;采用免疫组织化学染色技术检测滑膜组织OPN和整合素αvβ3的表达,ELISA方法检测血清TNF-α水平.结果 ① CIA模型组和MTX组大鼠的滑膜OPN、整合素αvβ3表达均明显高于正常大鼠对照组(均为P<0.01);与模型组比较,MTX组OPN和整合素αVβ3的表达减少(均为P<0.01). ②正常对照组和MTX组大鼠血清TNF-α水平显著性低于模型组大鼠(均为P<0.01).结论 滑膜OPN和整合素αvβ3异常表达在CIA发病中具有重要意义.MTX通过下调滑膜OPN和整合素αvβ3的表达,降低血清TNF-α水平从而达到治疗CIA的作用.     

肾上腺髓质素对豚鼠心室肌细胞L-型钙通道的作用及其信号转导机制

目的: 研究肾上腺髓质素( adrenomedullin, ADM)抑制豚鼠心室肌细胞L-型钙通道的信号转导机制。方法: 应用全细胞膜片钳技术,记录应用ADM(1-100 nmol·L^-1)前后L-型钙电流(I_Ca,L),以及分别记录应用ADM特异性受体拮抗剂ADM_22-52(100 nmol·L^-1)+ADM(100 nmol·L^-1)、蛋白激酶A (PKA) 特异性拮抗剂H-89(10 μmol·L^-1) + ADM(100 nmol·L^-1)、蛋白激酶C (PKC) 特异性拮抗剂PKC_19-36(10 μmol·L^-1)+ADM(100 nmol·L^-1)、PKC特异性激动剂PMA(1 μmol·L^-1)前后I_Ca,L。结果: ADM(1-100 nmol·L^-1)浓度依赖性地抑制豚鼠心室肌细胞I_Ca,L,并可被ADM_22-52(100 nmol·L^-1)完全阻断;H-89(10 μmol·L^-1)对ADM抑制I_Ca,L的作用无影响。PKC_19-36(10 μmol·L^-1)可完全阻断ADM 对I_Ca,L的抑制效应,且PMA(1 μmol·L^-1)可模拟ADM 对I_Ca,L的抑制效应。结论: ADM作用于特异性ADM受体可浓度依赖性地抑制豚鼠心室肌细胞I_Ca,L,此作用有可能与PKC激活相关。     

人核受体hLRH-1不同变异体在多种肿瘤组织和细胞系中的表达

目的:初步分析人核受体hLRH-1不同变异体在多种肿瘤组织和细胞系中的表达。方法:常规RT-PCR法分析hLRH-1v1和hLRH-1在肝癌等多种肿瘤组织和HepG2等肿瘤细胞系中的表达情况，实时定量PCR法分析hLRH-1v1，hLRH-1和hOct4在HepG2，SMMC-7721和BEL-7402三株肝癌细胞系的表达水平。结果:hLRH-1v1的表达见于所有检测的12种类型肿瘤和8种恶性肿瘤细胞系，hLRH-1的表达则仅在12种类型肿瘤中的6种肿瘤组织中可检测到，但8种恶性肿瘤细胞系均为hLRH-1阳性表达；在HepG2，SMMC-7721和BEL-7402三株肝癌细胞系中hLRH-1v1和hOct4的表达呈正相关。结论:hLRH-1v1在肿瘤中广泛表达，可能在维持肿瘤干细胞的自我更新中发挥重要作用。     

SARS患者TGFβ1和PDGF-BB的动态监测及其临床意义

目的动态监测严重急性呼吸综合征(SARS)患者血清转化生长因子β1(TGFβ1)和血小板衍生生长因子BB(PDGF-BB)水平的变化,以探讨细胞因子在SARS疾病中的作用。方法采用酶联免疫吸附试验 ,测定SARS患者早期、恢复期和随访时TGFβ1和PDGF -BB含量 ,并与急诊等一线未患SARS组及健康对照组比较 ,作描述性分析及方差分析。结果SARS患者早期组血清TGFβ1均值高于恢复期组和随访组 (P<0.05),SARS恢复期组、随访组TGFβ1均值均显著低于急诊等一线未患SARS组和健康对照组(P<0.01),其它组间两两比较均无显著性差异(P>0.05)。五组人群PDGF -BB均值水平总体比较无显著性差异(P>0.05)。结论TGFβ1可能与SARS患者机体调节免疫应答和免疫损伤有关 ,PDGF -BB与SARS的免疫损伤无关。     

Characterization of a gene encoding survival motor neuron (SMN)-related protein, a constituent of the spliceosome complex

Mutations in the gene encoding the Survival Motor Neuron (SMN) protein are responsible for autosomal recessive proximal spinal muscular atrophy (SMA). SMN orthologues have been identified in the nematode worm Caenorhabditis elegans and the yeast Schizosaccharomyces pombe but, to date, no human paralogues have been described. Here we describe identification and characterization of an SMN-related protein (SMNrp) gene that encodes a novel protein of 239 amino acids, which has recently been identified as a constituent of the spliceosome complex and designated SPF30. Significant similarity to the SMN protein is apparent only within a central region of SMNrp that represents a tudor domain. The SMNrp/SPF30 gene has been mapped to chromosome 10q23. It is differentially expressed, with abundant levels in skeletal muscle. An exclusively nuclear localization for SMNrp in cultured cells and muscle sections was revealed using GFP fusion constructs and thereafter confirmed with a polyclonal antibody raised against SMNrp. Overexpression of SMNrp as a fusion protein in HeLa cells in culture induced dose-dependent apoptosis with positive TUNEL staining. In addition to a possible role for this protein as a pro-apoptotic factor, SMN and its related protein share significant similarities in sequence and cellular function.      

Comparison of the structure of human intervertebral discs in the cervical,thoracic and lumbar regions of the spine

Posterior and anterior heights, cross-sectional area and shape were measured for all the intervertebral discs in four spines from elderly human cadavers. Disc height was a minimum at the T4-5 level; thoracic discs were less wedge-shaped than those in the cervical and lumbar regions. Cross-sectional area increased from the cranial to caudal extremity; at the L5-S1 level the nucleus pulposus occupied a high proportion of this area. Cervical discs tended to have an elliptical cross-sectional shape, thoracic discs were more circular and lumbar discs tended to have an elliptical cross-section which was flattened or re-entrant posteriorly. This shape distribution was quantified by defining a shape index which had a maximum value of 1 for a circular cross-section. Orientations of the reinforcing fibres in the outer lamellae of the anterior annulus fibrosus were measured from 27 discs by X-ray diffraction. For these measurements, C3-4, T7-8 and L2-3 were chosen as representative of cervical, thoracic and lumbar discs. The fibre tilt, with respect to the axis of the spine, was significantly less in the cervical discs (at 65 degrees) than in the thoracic and lumbar discs (about 70 degrees). These findings are interpreted in relation to differing functional requirements and possible mechanisms of failure in the cervical, thoracic and lumbar regions of the spine in the light of current knowledge on the biomechanics of the intervertebral disc.     

内洋地黄素拮抗剂上调缺血再灌注损伤大鼠心肌细胞膜钠泵亚基的表达

目的： 观察内洋地黄素特异性拮抗剂地高辛抗血清对心肌缺血再灌注（MIR）损伤大鼠心肌组织内洋地黄素水平、钠泵活性、线粒体总钙浓度以及钠泵各亚基基因表达的影响，探讨内洋地黄素在心肌缺血再灌注损伤中的作用及其机制。方法: 将56只雄性SD大鼠随机分成7组，每组8只。假手术对照组（sham）：丝线穿过左冠状动脉前降支，但不结扎；缺血再灌注组（MIR）：结扎左冠状动脉前降支30 min，再灌注45 min；生理盐水组（NS）、维拉帕米组（Ver）、小剂量、中剂量、大剂量地高辛抗血清组（ADA）：于再灌注前5 min经股静脉分别注射生理盐水、维拉帕米5 mg·kg^-1、地高辛抗血清8.6 mg·kg^-1、 17.3 mg·kg^-1、34.5 mg·kg^-1，容积均为5 mL·kg^-1，5 min内注射完毕，其余同MIR模型组。再灌注结束后，立即取缺血区左室心肌检测心肌匀浆内洋地黄素水平、心肌细胞膜Na+ K+_ATP酶和Ca2+_Mg2+_ATP酶活性、线粒体总钙浓度；分别采用RT-PCR及Western blotting方法和免疫组化方法检测心肌钠泵α₁、α₂、α₃和β₁亚基mRNA及蛋白水平基因表达的改变。结果: 心肌缺血再灌注损伤时，心肌组织内洋地黄素水平明显升高，心肌细胞膜钠泵和Ca2+_Mg2+_ATP酶活性显著下降，线粒体总钙浓度升高，钠泵α₁、α₂、α₃和β₁亚基在mRNA及蛋白水平基因表达均明显下降；维拉帕米除具有降低线粒体总钙浓度外，对其它各项指标无明显影响。地高辛抗血清呈剂量依赖性地显著降低心肌组织内洋地黄素水平，恢复细胞膜钠泵和Ca2+_Mg2+_ATP酶活性，降低线粒体总钙浓度，上调钠泵α₁、α₂、α₃和β₁亚基mRNA及蛋白水平的基因表达。结论: 心肌缺血再灌注促进机体内洋地黄素分泌增加，后者通过下调心肌细胞膜上的钠泵α₁、α₂、α₃和β₁亚基基因表达抑制钠泵活性，进而抑制Ca2+_Mg2+_ATP酶活性，导致线粒体内钙超载，介导心肌缺血再灌注损伤。内洋地黄素特异性拮抗剂地高辛抗血清通过阻断内洋地黄素的生物学作用，上调钠泵各亚基的基因表达，发挥其抗心肌缺血再灌注损伤的作用。     

Reduction of adhesion formation in rabbits by intraperitoneal administration of lazaroid formulations

Adhesion formation is a major source of postoperative morbidity and mortality. In this study, the ability of a variety of lazaroid formulations [the antioxidant 21-aminosteroid PNU74006F (tirilazad) and the non-steroidal 2-methylaminochroman derivative PNU83,836E] to reduce i.p. adhesion formation in three rabbit models was examined. In initial studies, PNU83836E was administered via Alzet miniosmotic pump to the site of injury. In the sidewall and double uterine horn models, PNU83,836E was administered via Alzet miniosmotic pump for the entire postoperative interval. In the sidewall model, there was a dose- dependent reduction in the area of the sidewall injury that was involved in adhesions. In the double uterine horn model, PNU83,836E was administered via Alzet miniosmotic pump to the area of injury for 1, 2, 3 or 7 days. Administration for as little as 24 h after surgery significantly reduced the extent of adhesion formation and the reduction was increased if it was administered for longer. Further studies were conducted in which various lazaroid formulations were administered as a bolus at the end of surgery. In both the sidewall and double uterine horn models, administration of either PNU83,386E (in citrate buffer) or PNU74006F (in cyclodextrin or lipid emulsion vehicles) at the end of surgery reduced adhesion formation. Administration of a bolus of PNU74006F 10 min prior to initiation of surgery with or without additional treatment at the end of surgery further increased its efficacy in the reduction of adhesion formation. Administration of a minimum of 1.5 mg before and after surgery (3 mg total) was required for maximal efficacy. These studies demonstrate that pre- and postoperative administration of either a steroidal (PNU74006F) or non-steroidal (PNU83,836E) lazaroid intraperitoneally reduced the formation and reformation of postoperative adhesions in three animal models.