采用一种新介质纯化神经生长因子

采用一种新闻子交换介质Ｅｘｐｒｅｓｓ－ＩｏｎＣ（简称ＩｏｎＣ）使鼠神经生长因子（ｍＮＧＦ）能得到规模纯化。以鼠颌下腺为原料,匀浆后,经Ｅｘｐｒｅｓｓ－ＩｏｎＣ纯化得单一组分的ｍＮＧＦ,用ＳＤＳ－ＰＡＧＥ测定其相对分子质量约为１３．７×１０＾３,比活约２．３×１０＾５Ｕ／ｍｇ。结果表明ＩｏｎＣ可替代ＣＭ－５２,且更适于工因子的规模化生产。     

有关青霉素类药物的制备

青霉素类药物是一类高效广谱抗生素,自四十年代初青霉素应用于临床来,人们又发现或人工合成其他一些青霉素类药物以及青霉素类抗生素,如青霉素G类、青霉素V类、耐酶青霉素、氨苄西林类、抗假单胞菌青霉素、美西林及其酯匹西林、甲氧西林类等。作为青霉素类药物及抗生素典型代表之一,替卡西林钠和半合成青霉素的原料——6-氨基青霉烷酸(6-APA)的制备工艺将在下文得到详细探究。     

重组人白细胞介素—2制备工艺的研究

本文对大肠杆菌表达的重组人白细胞介素-2进行了制备工艺的研究。用4mol／L脲溶解可溶性细菌蛋白后可使rIL—2包涵体纯度达70％;在变性条件下进行凝胶过滤并收集rlL－2主峰纯度可达90％;利用Cu2 氧化复性;最后用反相HPLC纯化,得到高度均一,纯度高达98％,比活达到8．0×106U／mg蛋白,且无热源,无残留DNA的rIL—2;每次反相色谱分离过程可获得400mg左右的rIL－2,得率约25％。     

核酸疫苗制备工艺研究进展

核酸疫苗是指被用作疫苗的带有编码外源蛋白抗原基因的真核表达质粒,它能较安全地表达目的蛋白,是具有较大发展潜力的一类生物制品。研究核酸疫苗的制备工艺,对于规模化生产成本低、免疫效果好的疫苗具有重要的现实意义。核酸疫苗规模化生产工艺的流程主要包括核酸疫苗的构建、工程菌的发酵、菌体裂解、分离纯化及产品检验等关键环节,而每个环节对核酸疫苗的质量都有较大的影响。     

神经生长因子的研究及应用进展

神经生长因子的研究具有重要的理论和临床意义。介绍了近年来神经生长因子的结构和基因表达的研究、鼠神经生长因子的生产和临床应用情况,对重组人神经生长因子(rh NGF)的表达和应用研究进行了综述,对于NGF未来的研究发展提出了建设性分析。     

静脉注射用人血免疫球蛋白工艺改进

以低温乙醇法组份Ⅱ (ＣｏｈｎⅡ )为原料 ,经 4%乙醇低温沉淀和ＤＥＡＥ -ＳｅｐｈａｄｅｘＡ -5 0吸附提纯并加人血白蛋白保护的完整ＩｇＧ制备方法是一种较理想的方法[1] 。该法制取的ＩＶＩＧ安全有效 ,符合世界卫生组织 (ＷＨＯ)专家委员会制定的质量要求[2 ] 。具有ｐＨ中性 ,更接近人体生理ｐＨ ;ＩｇＧ亚类俱全且相对构成比同正常人血浆 ;保持了ＩｇＧ分子结构完整 ,生物学功能完全等诸多优点。加入人血白蛋白保护剂可有效地保护ＩｇＧ分子在制备过程中免遭潜在构型的变化 ,保持较低的抗补体活性[1 4] 。不同厂家ＩＶＩＧ制品中人血…     

银杏叶黄酮干浸膏的制备工艺研究

银杏叶黄酮干浸膏的制备工艺研究张卫明,王红,赵伯涛（内贸部南京野生植物综合利用研究所）目前,国际市场银杏叶活性物质制品的年销售额已经超过２０亿美元,其中银杏叶黄酮制剂年销售量突破１０亿美元,尽管如此,仍缺口较大,供不应求［１,２,３］。欧美及日本对从...     

马齿苋提取物制备工艺、安全性及抗敏功效的研究

以透明质酸酶抑制率为考察指标,通过正交实验,确定了最佳醇提工艺:乙醇浓度为75%(体积分数),料液比1∶10,提取温度60℃,提取时间1 h,提取液过滤脱色浓缩冷冻干燥后,得到马齿苋醇提物。同浓度下的马齿苋醇提物的透明质酸酶抑制率远高于水提物,红细胞溶血实验说明马齿苋水提物和醇提物的刺激性低,安全性高。人体斑贴实验表明,马齿苋醇提物能减轻或抑制常见致敏源对皮肤的刺激作用,减弱皮肤炎症反应,增强皮肤的屏障功能。     

神经生长因子生物活性检定方法的建立

采用鸡胚背根神经节体外培养法,建立了神经生长因子生物活性的检定方法,对判定神经生长因子的生物活性单位制定了明确统一的判定标准     

Epidermal growth factor receptors in fetal and maternal rabbit lung

The pattern of morphologic and functional development of lung during intrauterine period is influenced by several endogenous compounds. Recently Epidermal Growth Factor (EGF), when administered in vivo, has been shown to accelerate pulmonary maturation in fetal rabbit and sheep. We sought evidence for EGF receptor occurrence in fetal and maternal rabbit lung plasma membranes. The percent specific binding (mean ± S.E.M.) (125-I) EGF to LPM in the mother (n=5) and the fetus at term (n=7) was 1.08 ± 0.08 and 2.25 ± 0.12 per 175 μg of LPM protein respectively. The number of receptor sites per mg of LPM protein in the mother were significantly less than that in the fetus (44 ± 11 and 250 ± 24 × 10^?10, p < 0.001) with no apparent differences in Kd (2.10 ± 0.39 and 2.47 ± 0.24 × 10⁹). Presence of high affinity receptors for EGF in fetal and maternal lung plasma membranes suggests a direct role of EGF in fetal lung maturation.     

Nerve growth factor induced turnover of phosphatidylinositol in rat superior cervical ganglia

The addition of nerve growth factor to organ cultures of superior cervical ganglia from immature rats specifically stimulated the incorporation of 32P-orthophosphate into phosphatidylinositol fraction. Equimolar concentrations of other hormones such as insulin, glucagon, thyroxine and growth hormone did not cause any stimulation of the incorporation of 14C-myoinositol into phosphatidylinositol. The stimulation of phosphatidylinositol turnover was observed over a concentration of nerve growth factor ranging from 10^?10M to 10^?7M. Nerve growth factor specific “inositide effect” was found to be sensitive to nerve growth factor antibody, 2,4-dinitrophenol, a high concentration of bovine growth hormones but not to Actinomycin D. The physiological significance of this finding in relation to nerve growth factor action in this target tissue is discussed.     

Acidic fibroblast growth factor (FGF) potentiates glial-mediated neurotoxicity by activating FGFR2 IIIb protein

Previous studies indicate that astrocytes are the brain cells that express acidic fibroblast growth factor (aFGF) and that the expression is increased upon activation. However, there has been no study investigating the significance of this phenomenon. Here we report that aFGF treatment of IFNγ-stimulated human astrocytes, and LPS/IFNγ-stimulated human microglia, enhances their secretion of inflammatory cytokines and other materials toxic to human neuroblastoma SH-SY5Y cells. The mechanism of aFGF enhancement involves stimulation of the receptor FGFR2 IIIb. We show by RT-PCR that this receptor, but not other FGF receptors, is robustly expressed by astrocytes and microglia. We establish by Western blotting, and immunohistochemistry on postmortem human brain tissue that the FGFR2 IIIb protein is expressed by both of these glial cell types. We blocked the inflammatory stimulant action of aFGF by transfecting microglia and astrocytes with a small inhibitory RNA (siRNA) to FGFR2 IIIb as well as by removal of aFGF using an anti-aFGF antibody. Treatment with bFGF in combination with the stimulants was without effect, but together with aFGF, it partially counteracted the action of aFGF, indicating that it may be a weak antagonist of FGFR2 IIIb. The inflammatory effect was also attenuated by treatment with inhibitors of protein kinase C, Src tyrosine kinase, and MEK-1/2 indicating the involvement of these intracellular pathways. Our data suggest that inhibition of expression or release of aFGF could have therapeutic potential by inhibiting inflammation in neurodegenerative diseases such as Alzheimer disease where many neuroinflammatory molecules are prominently expressed.     

The epidermal growth factor.

Epidermal growth factor (EGF) is a single polypeptide of 53 amino acid residues which is involved in the regulation of cell proliferation. Egf exerts its effects in the target cells by binding to the plasma membrane located EGF receptor. The EGF receptor is a transmembrane protein tyrosine kinase. Binding of EGF to the receptor causes activation of the kinase and subsequently receptor autophosphorylation. The autophosphorylation is essential for the interaction of the receptor with its substrates. These bind to the receptor by the so-called SH2 domains. The signal transduction pathways activated by EGF include the phosphatidylinositol pathway, leading to activation of protein kinase C and to increase in the intracellular Ca2+ concentration, and to the ras pathway leading to MAP kinase activation. Recently the cytoplasm has been implicated as playing an important role in EGF induced signal transduction. The EGF receptor has been demonstrated to be an actin-binding protein. In addition EGF causes a rapid actin depolymerisation and the formation of membrane ruffles. In particular these membrane ruffles have been shown to act as the first site of signal transduction after EGF binding, and thus may be considered as signal transduction structures. Finally evidence has been presented suggesting a positive role for EGF and/or the receptor in the nucleus.     

Fibroblast growth factor 21 (FGF21) inhibits chondrocyte function and growth hormone action directly at the growth plate

Fibroblast growth factor 21 (FGF21) modulates glucose and lipid metabolism during fasting. In addition, previous evidence indicates that increased expression of FGF21 during chronic food restriction is associated with reduced bone growth and growth hormone (GH) insensitivity. In light of the inhibitory effects on growth plate chondrogenesis mediated by other FGFs, we hypothesized that FGF21 causes growth inhibition by acting directly at the long bones' growth plate. We first demonstrated the expression of FGF21, FGFR1 and FGFR3 (two receptors known to be activated by FGF21) and β-klotho (a co-receptor required for the FGF21-mediated receptor binding and activation) in fetal and 3-week-old mouse growth plate chondrocytes. We then cultured mouse growth plate chondrocytes in the presence of graded concentrations of rhFGF21 (0.01-10 μg/ml). Higher concentrations of FGF21 (5 and 10 μg/ml) inhibited chondrocyte thymidine incorporation and collagen X mRNA expression. 10 ng/ml GH stimulated chondrocyte thymidine incorporation and collagen X mRNA expression, with both effects prevented by the addition in the culture medium of FGF21 in a concentration-dependent manner. In addition, FGF21 reduced GH binding in cultured chondrocytes. In cells transfected with FGFR1 siRNA or ERK 1 siRNA, the antagonistic effects of FGF21 on GH action were all prevented, supporting a specific effect of this growth factor in chondrocytes. Our findings suggest that increased expression of FGF21 during food restriction causes growth attenuation by antagonizing the GH stimulatory effects on chondrogenesis directly at the growth plate. In addition, high concentrations of FGF21 may directly suppress growth plate chondrocyte proliferation and differentiation.     

外源性神经生长因子对痴呆老龄鼠学习和记忆能力影响的初步探讨

目的探讨外源性神经生长因子（NGF）对痴呆老龄鼠智能影响的机制。方法本实验选用18月龄ICR小鼠45只，应用整体实验和免疫组织化学技术，观察给药前后各组迷宫试验、胆碱乙酰转移酶活性（chAT-IR）、神经生长因子抗体（Anti-NGF）在相关脑区的表达并进行统计学分析。结果用药后学习及记忆能力有明显改善（P〈0．05），与用药前比较ChAT-IR明显增加（P〈0．01），NGF抗体表达明显增加（P〈0．01）。结论外源性NGF对痴呆老龄鼠的智能有改善作用；能够使相关脑区ChAT-IR增加；相关脑区Anti-NGF表达增加；外源性NGF能够保护、支持、修复神经原。     

神经生长因子在不同周龄小鼠睾丸组织中的表达

目的研究神经生长因子在小鼠不同周龄睾丸组织中的定量和定位表达。方法分别剖取不同周龄雄性小鼠的睾丸组织,部分提取总RNA,real-time PCR相对定量分析神经生长因子mRNA的表达量;另外部分组织固定、包埋,进行SABC法免疫组化分析,以观察神经生长因子蛋白在各周睾丸组织中的定位。结果Real-timePCR定量分析表明:小鼠生后1周龄睾丸组织有神经生长因子mRNA的表达,生后3周龄表达量达峰值,5周之后随鼠龄的增加呈下降趋势,成年小鼠睾丸组织的神经生长因子mRNA表达维持在一定水平。免疫组化定位分析显示:睾丸组织的神经生长因子蛋白表达于小鼠出生后的各个时期内,1周龄睾丸组织免疫阳性反应主要位于支持细胞,精原细胞也有着色;3周龄睾丸组织的间质细胞、各级生精细胞、支持细胞、管周肌样细胞表达均呈现阳性;5周后的睾丸组织内神经生长因子呈低水平表达,主要表达于间质细胞和生精细胞内。结论神经生长因子mRNA的表达量随着小鼠睾丸的生长发育期存在着一定的规律性变化;神经生长因子蛋白的表达在小鼠睾丸生长发育的不同时期其主要表达部位不同。     

蛇毒神经生长因子促进周围神经再生的诱发电位观察

目的：研究蛇毒神经生长因子（sNGF)对大鼠坐骨神经损伤后诱发电位的影响,评价蛇毒神经生长因子在促进周围神经再生中的作用。方法：建立大鼠坐骨神经钳夹模型,局部滴加药物和术后肌注sNGF,通过脊髓诱发电位（SEP）,运动诱发电位（MEP）评定,观察坐骨神经修复情况。结果：sNGF治疗后可使伤后SEP,MEP提早出现,结论：蛇毒提取的NGF对大鼠坐骨神经损伤修复具有促进作用。     

Conversion of a paracrine fibroblast growth factor into an endocrine fibroblast growth factor

FGFs 19, 21, and 23 are hormones that regulate in a Klotho co-receptor-dependent fashion major metabolic processes such as glucose and lipid metabolism (FGF21) and phosphate and vitamin D homeostasis (FGF23). The role of heparan sulfate glycosaminoglycan in the formation of the cell surface signaling complex of endocrine FGFs has remained unclear. Here we show that heparan sulfate is not a component of the signal transduction unit of FGF19 and FGF23. In support of our model, we convert a paracrine FGF into an endocrine ligand by diminishing heparan sulfate-binding affinity of the paracrine FGF and substituting its C-terminal tail for that of an endocrine FGF containing the Klotho co-receptor-binding site to home the ligand into the target tissue. In addition to serving as a proof of concept, the ligand conversion provides a novel strategy for engineering endocrine FGF-like molecules for the treatment of metabolic disorders, including global epidemics such as type 2 diabetes and obesity.