转化生长因子β对人颈椎关节突关节软骨细胞基质金属蛋白酶13基因表达的调节作用及意义

目的 探讨转化生长因子β（TGF-β）对人的颈椎关节突关节透明软骨细胞基质金属蛋白酶13（MMP-13）基因表达的作用，旨在阐明颈椎退行性变的相关发生机理。方法 应用逆转录方法PCR及实时荧光定量方法，检测不同浓度TGF-β作用传代培养人的透明软骨细胞MMP-13mRNA的含量。另外3种不同浓度分别与10ng／ml IL-1β组成联合作用组，共计6个实验组及1个正常对照组。结果 正常对照组中透明软骨细胞仅见MMP-13mRNA扩增产物，实验组TGF-β1、10和100ng／ml作用12h后，MMP-13mRNA表达逐渐增强；而联合作用组中，随着TGF-β1浓度的升高，MMP-13mRNA表达逐渐降低，并且各组之间存在明显的差异（P〈0．05）。结论 TGF-β可按剂量依赖方式调节颈椎关节突关节软骨细胞MMP-13mRNA的表达。     

sFGFR1基因的克隆与在RTS系统中的高效表达

目的：克隆sFGFRl(soluble fibroblast growth factors receptor-1)基因，并在RTS(rapid translation system)系统中高效表达相应蛋白．方法：培养Swiss rat 3T3 fibroblast细胞株，提取总RNA，用RT—PCR方法获取鼠sFGFR1 cDNA片段，酶切后克隆到pIVEX2．3d载体并进行序列分析；采用Roche RTS ProteinMaster500系统，高效表达sFGFR1蛋白并用Western Blot鉴定表达的蛋白．结果：克隆了sFGFR1基因，测序证实序列正确；Western Blot证实sFGFR1蛋白在RTS系统中高效表达．结论：克隆了sFGFR1基因并在RTS系统获得高效表达．     

子宫内膜异位症患者血清及腹腔液中血小板衍生生长因子、血管细胞粘附分子水平的变化及其意义

目的通过检测子宫内膜异位症(EMs)患者血清及腹腔液中血小板衍生生长因子(PDGF)、血管细胞粘附分子-(VCAM-1)浓度,探讨PDGF和VCAM-1在EMs发病中的作用。方法选取手术后病理证实为EMs的40例患者为EMs组,其中I~II期17例,III~IV23例;非EMs组20例作为对照组。应用酶联免疫吸附法(ELISA)检测血清及腹腔液中PDGF和VCAM-1水平。结果EMs组血清及腹腔液中PDGF、VCAM-1水平均明显高于对照组(P<0.01)。随EMs期别的增加,其血清和腹腔液中PDGF、VCAM-1含量呈上升趋势;EMsIII~IV期水平显著高于I~II期(P<0.05)。EMs患者PDGF与VCAM-1呈正相关性(P<0.05)。结论EMs患者PDGF、VCAM-1表达水平升高,在EMs的发生发展中具有重要作用。     

Transforming growth factor alpha treatment alters intracellular calcium levels in hair cells and protects them from ototoxic damage in vitro

To determine if transforming growth factor alpha (TGFα) pretreatment protects hair cells from aminoglycoside induced injury by modifying their intracellular calcium concentration, we assayed hair cell calcium levels in organ of Corti explants both before and after aminoglycoside (i.e. neomycin, 10⁻³M) exposure either with or without growth factor pretreatment. After TGFα (500ng/ml) treatment, the intracellular calcium level of hair cells showed a five-fold increase as compared to the levels observed in the hair cells of control cultures. After ototoxin exposure, calcium levels in hair cells of control explants showed an increase relative to their baseline levels, while in the presence of growth factors pretreatment, hair cells showed a relative reduction in calcium levels. Pretreatment of organ of Corti explants afforded significant protection of hair cell stereocilia bundle morphology from ototoxic damage when compared to explants exposed to ototoxin alone. This study correlates a rise in hair cell calcium levels with the otoprotection of hair cells by TGFα in organ of Corti explants.     

Decreased serum levels of nutritional biochemical indices in healthy children with marginally delayed physical growth

Biochemical markers of nutritional status (albumin, transthyretin, insulin-like growth factor-I and zinc) were measured in slowly growing two- to five-year-old, low-income Parisian children whose weight-for-height or height-for-age z scores (WHZ or HAZ) were between — 1 and — 2 SD of the NCHS median. The results were compared to controls who were matched for age, sex, and ethnic origin with WHZ and HAZ between — 1 and + 2 SD. Mean serum levels of transthyretin, albumin and insulin-like growth factor-I and mean plasma zinc concentrations were significantly lower in the growth-impaired children than in the controls ( p = 0.002, p = 0.006, p = 0.015, and p = 0.035, respectively). While the height-retarded children had low mean serum insulin-like growth factor-I values, the weight-retarded subjects had decreased levels of albumin, transthyretin and zinc when compared to controls. Lower mean levels of nutritional markers in healthy, slowly growing children suggest that inadequate dietary intakes of zinc, protein and/or energy may result in marginal delays in weight and height gains.     

人碱性成纤维细胞生长因子基因在大肠杆菌中的克隆与表达

应用DNA重组技术将编码人碱性成纤维细胞生长因子（bbFGF）的基因克隆至原核高效表达质粒pBV_(221)的启动子下游。SDS-SAGE、ELISA和NTT活性监测结果表明:该重组质粒pBV-hbFGF在大肠杆菌DH5α中,经42℃诱导后,可表达出有较高生物活性的hbFGF。     

Protein kinase C isozymes that mediate enhancement of neurite outgrowth by ethanol and phorbol esters in PC12 cells

Using PC12 cells to study ethanol's effects on growth of neural processes, we found that ethanol enhances NGF- and basic FGF-induced neurite outgrowth. Chronic ethanol exposure selectively up-regulates δ and ε protein kinase C (PKC) and increases PKC-mediated phosphorylation in PC12 cells. Since PKC regulates differentiation, we investigated the role of PKC in enhancement of neurite outgrowth by ethanol. Like ethanol, 0.3–10 nM phorbol 12-myristate, 13-acetate (PMA) increased NGF-induced neurite outgrowth. However, higher concentrations did not, and immunoblot analysis demonstrated that 100 nM PMA markedly depleted cells of β, δ and ε PKC. PMA (100 nM) also down-regulated β, δ and ε PKC in ethanol-treated cells and completely prevented enhancement of neurite outgrowth by ethanol. In contrast, the cAMP analogue 8-bromoadenosine cAMP did not completely mimic the effectsof ethanol on neurite outgrowth, and ethanol was able to enhance neurite formation in mutant PC12 cells deficient in protein kinase A (PKA). These findings implicate β, δ or εPKC, but not PKA, in the neurite-promoting effects of ethanol and PMA. Since chronic ethanol exposure up-regulates δ and ε, but not βPKC, these findings suggest that δ or εPKC regulate neurite outgrowth.     

Expression and distribution of vascular endothelial growth factor protein in human brain tumors

Marked neovascularization is a hallmark of many neoplasms in the nervous system. Recent reports indicate that the endothelial mitogen vascular endothelial growth factor (VEGF) may play a critical role in the regulation of vascular endothelial proliferation in malignant gliomas. Using novel monoclonal antibodies to the VEGF polypeptide we have determined the expression and cellular distribution of VEGF protein in a representative series of 171 human central nervous system (CNS) tumors by immunohistochemistry and immunoblotting. In agreement with previous in situ hybridization data, 19 out of 20 glioblastomas (95%) showed immunoreactivity for VEGF, whereas both the percentage of immunoreactive tumors and the extent of immunoreactivity for VEGF were significantly lower in astrocytomas. Of the pilocytic astrocytomas (WHO grade I) 44% were immunoreactive for VEGF, but we observed several cases with pronounced vascular proliferates in the absence of VEGF. In ependymomas, meningiomas, hemangioblastomas, and primitive neuroectodermal tumors, there was no correlation between VEGF expression, vascular endothelial proliferation and the grade of malignancy. Oligodendrogliomas and the oligodendroglial component of mixed gliomas lacked immunoreactive VEGF, indicating that endothelial growth factors other than VEGF may regulate tumor angiogenesis in these neoplasms. Western blot analysis showed a predominant VEGF protein species of 23 kDa and confirmed the immunohistochemical data in all cases. Our findings demonstrate that VEGF is expressed in a wide spectrum of brain tumors in which it may induce neovascularization. However, other angiogenic factors also appear to contribute to the vascularization of CNS neoplasms. Received: 18 April 1996 / Revised, accepted: 20 August 1996     

牛胎盘中肝细胞生长因子的纯化

用高速离心、分段盐析、亲和层析、超滤和阴离子交换层析法，从牛胎盘中分离纯化出一种肝细胞生长因子。结果表明，此因子的最终得率为０．００５ｍｇ／ｇ牛胎盘，其分子量约为９９０００ｕ，它能强烈刺激原代培养大鼠肝细胞的ＤＮＡ合成。提示利用自制的亲和层析凝胶，通过此提纯流程可以得到一种肝细胞生长因子。