灰树花胞外多糖对四氯化碳致小鼠肝损伤的保护作用

四氯化碳可导致小鼠急性肝损伤,采用灰树花胞外多糖(GFP)防治后,对其血清中丙氨酸氨基转移酶(ALT),天门冬氨酸氨基转移酶(AST)和过氧化氢酶活力(CAT)以及肝组织匀浆中的丙二醛(MDA)和乳酸脱氢酶(LDH)进行测定,与模型组相比较,灰树花胞外多糖治疗组ALT、AST、MDA、LDH活力明显降低,而CAT活力明显升高。通过组织切片染色可以直观的看出灰树花胞外多糖能显著减轻肝组织病理变化程度。结果显示GFP对CCL4致小鼠急性肝损伤具有保护作用。     

育阴软肝中药对实验性肝损伤的保护作用

目的:研究育阴软肝方对小鼠化学性急性肝损伤的保护作用。方法:将55只昆明小鼠随机分为正常对照组、模型对照组、育阴软肝方低、中、高剂量组(n=11),连续给药7 d后,采用腹腔分别注射D-半乳糖胺(DGal N)、四氯化碳(CCl4)或硫代乙酰胺(TAA)复制三种肝损伤模型,通过测定血液生化指标、肝组织抗氧化酶及氧化产物的水平,研究育阴软肝方对实验性肝损伤的保护作用。结果:育阴软肝方能降低D-Gal N、CCl4或TAA诱发急性肝损伤小鼠血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)的水平,提高急性肝损伤小鼠肝组织超氧化物岐化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活性,降低丙二醛(MDA)的含量。其降酶保肝、抗氧化作用显示出一定的量效关系。结论:育阴软肝方对实验性急性肝损伤具有一定的保护作用。     

水飞蓟素对四氯化碳致小鼠肝损伤的保护作用

目的:探讨水飞蓟素对四氯化碳致(CCl4)小鼠肝损伤是否有保护作用。方法:60只ICR小鼠随机分为6组(n=10),正常组、模型组、联苯双酯阳性对照组,低、中、高剂量水飞蓟素组(100、200、400 mg/kg)。各组连续给药10 d,末次给药1 h后,正常组腹腔注射橄榄油,其余各组腹腔注射0.12%的CCl4橄榄油溶液,16 h后测定血清中丙氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST),肝浆中丙二醛(MDA),谷胱甘肽过氧化物酶(GSH-Px)和超氧化物岐化酶(SOD)的水平。结果:水飞蓟素各剂量组能显著的抑制肝损伤血清中ALT和AST的升高(P<0.05,P<0.01),亦能抑制肝组织中MDA的升高(P<0.01),增加肝组织中SOD的活性和GSH-Px的水平(P<0.05)。结论:水飞蓟素具有明显的四氯化碳致小鼠肝损伤的保护作用。     

育阴软肝颗粒剂对肝纤维化大鼠TGF-β1表达的影响

目的：观测育阴软肝颗粒剂对大鼠肝纤维化模型的防治作用及对转化生长因子-β1（TGF-β1）表达的影响。方法：将Wistar大鼠分为6组（n=10）,注射四氯化碳、饲以高脂饲料并饮用20%乙醇6周复制肝纤维化大鼠模型,经6.2~24.8 g/kg育阴软肝颗粒剂干预（qd）6周后,测定肝纤维化大鼠血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）活性、透明质酸（HA）、Ⅲ型前胶原（PCⅢ）、Ⅳ型胶原（C-Ⅳ）及板层素（LN）含量,观测肝组织病理学及肝组织TGF-β1表达的变化,对育阴软肝颗粒剂防治肝纤维作用及机制进行研究。结果：实验第7周,模型组大鼠肝组织出现明显的纤维化病变（P<0.01）;与模型组比较,6.2~24.8g/kg的育阴软肝颗粒剂能明显降低肝指数以及血清ALT、AST活性与HA、PCⅢ、C-Ⅳ、LN含量,缓解肝组织纤维化病理变化,抑制纤维化肝组织TGF-β1的表达（P<0.05,0.01）。结论：育阴软肝颗粒剂对多因素复制肝纤维化大鼠造模具有明显的治疗作用,而抑制TGF-β1的表达可能是其作用机制之一。     

玄参提取物对小鼠急性化学性肝损伤保护作用的研究

采用四氯化碳(CCl4)腹腔注射构建小鼠急性肝损伤模型;利用生物活性跟踪法,以小鼠血清中谷丙转氨酶(ALT)活性和谷草转氨酶(AST)活性为检测指标,从玄参根提取物筛选保肝活性的物质。结果表明乙酸乙酯萃取部位保肝效果最好,能够显著降低血清ALT和AST活性(P0.01),其次为正丁醇相。对活性较好的乙酸乙酯部位进一步通过硅胶柱层析分离,结果表明段F02和段F03能显著降低血清ALT和AST活性(P0.05或P0.01),降低肝脏MDA含量(P0.05或P0.01),增强肝脏SOD活力(P0.05或P0.01),提示玄参提取物可能通过抑制脂质过氧化发挥保肝作用。     

水飞蓟宾·熊去氧胆酸蒸发共沉淀物对CCl_4致小鼠急性肝损伤的保护作用

目的:研究水飞蓟宾·熊去氧胆酸蒸发共沉淀物(SUE)对小鼠CCl4致急性肝损伤的保护作用。方法:健康昆明种雄性小鼠80只,随机分为8组(n=10):空白组及模型组分别经口投予羧甲基纤维素钠(CMC-Na),其余60只采用CCl4腹腔注射建立小鼠急性肝损伤模型,分别给予水飞蓟宾(SLB,20 mg/kg)、熊去氧胆酸(UDCA,16.25 mg/kg)、SLB与UDCA等摩尔物理混合物(PM,36.25 mg/kg)和高中低剂量SUE(以SLB计10、20、40 mg/kg)治疗,采用单因素方差分析肝体比变化,多功能酶标仪检测血清中丙氨酸氨基转移酶(ALT)、门冬氨酸氨基转移酶(AST)水平。结果:与空白组相比,模型组肝体比有显著性升高(P0.05),血清中AST和ALT水平明显升高(P0.05);与模型组相比SLB、PM、SUE组血清AST、ALT显示有不同程度的下降(P0.05),但UDCA组无显著性差异;与SLB和PM相比,SUE能明显降低小鼠血清ALT、AST含量(P0.05),且呈一定的剂量依赖关系。结论:SUE对CCl4所致小鼠急性肝损伤有较好的保护作用,说明LB与UDCA制备成共沉淀物后,可更好的发挥协同作用,提高联合应用的药效。     

瘦素和转化生长因子β1在大鼠肝纤维化过程中的作用

目的探讨瘦素和转化生长因子β1（transforming growthβ1,TGF-β1）在肝纤维化发生、发展过程中的作用。方法雌性Wistar大鼠随机分为正常对照组和纤维化模型1周组、2周组、4周组、6周组。纤维化模型各组以CCl4造成化学性肝损伤。常规HE染色观察肝脏病变;检测血浆和肝组织瘦素及TGF-β1水平;天狼猩红胶原染色和肝组织羟脯氨酸（Hyp）含量测定观察肝纤维化程度,并对肝组织瘦素水平、TGF-β1水平及肝纤维化指数（FI）进行相关性分析;赖氏法测定血浆丙氨酸氨基转移酶（ALT）。结果与正常对照组比较,纤维化模型各组血清和肝组织瘦素和TGF-β1水平显著升高（P〈0.05）,且纤维化模型各组肝组织瘦素水平、TGF-β1水平及FI之间两两均呈显著正相关。结论肝组织瘦素在肝纤维化发病过程中具有独立的致病作用,并可能通过激活TGF-β1通路导致肝维化的形成。     

小檗碱对肝硬化大鼠肠粘膜及肝脏保护作用的研究

目的:观察小檗碱对肝硬化大鼠肝脏和肠粘膜屏障的保护作用。方法:24只Wistar大鼠随机分为小檗碱干预组、肝硬化造模组、正常对照组。小檗碱干预组和肝硬化造模组予以四氯化碳联合酒精进行肝硬化造模。小檗碱干预组造模同时予以小檗碱灌胃,观察大鼠的一般情况、进食量、体重,第8周末处死全部大鼠,检测血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、内毒素(ET)水平,并取肝组织和回肠进行病理检查。结果:肝硬化造模组大鼠和小檗碱干预组大鼠进食量及体重有下降,肝硬化造模组下降大于小檗碱干预组,差别有统计学意义P 0.01。小檗碱干预组ALT,AST,ET水平均低于肝硬化造模组,差别有统计学意义P 0.01。肝脏病理观察:小檗碱干预组肝小叶结构破坏,假小叶形成,汇管区及小叶内炎症细胞浸润方面明显轻于肝硬化造模组。回盲部病理观察:小檗碱干预组的小肠绒毛缩短、变形、数量减少,上皮细胞排列紊乱方面轻于肝硬化造模组。结论:小檗碱对四氯化碳联合酒精所致的肝硬化大鼠有减轻肝损伤和保护肠粘膜的作用。     

京尼平苷四种不同给药途径的肝毒性初步研究

目的:依据临床的几种常规的给药方式,对比研究京尼平苷不同给药途径对肝脏的毒性作用,为其进一步研究开发及临床应用提供依据.方法:应用SD大鼠,采用口服(ig)、静注(iv)、肌注(im)、鼻腔(ns)四种给药途径给予京尼平苷溶液一个月.以肝脏指数、丙氨酸氨基转移酶(ALT)和天冬氨酸氨基转移酶(AST)为指标,考察不同给药途径下京尼平苷的肝脏毒性作用.结果:由肝脏指数得出:口服(ig)＞静注(iv)＞鼻腔(ns)≈肌注(im)＞空白(P＜0.05);由血清丙氨酸氨基转移酶(ALT)及天冬氨酸氨基转移酶(AST)的活性得出:静注(iv)＞口服(ig)＞肌注(im)＞鼻腔(ns)＞空白(P＜0.01).结论:综合上述指标分析,口服(ig)、静注(iv)、肌注(im)、鼻腔(ns)四种给药途径中,鼻腔(ns)给药方式的京尼平苷对肝脏的毒性作用较小.     

禹州漏芦醇提物对四氯化碳所致小鼠急性肝损伤的影响

探讨禹州漏芦乙醇提取物对四氯化碳(CCl4)诱导小鼠急性肝损伤的保护作用。以CCl4诱导小鼠急性肝损伤模型,检测血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)活性,同时测定肝匀浆中的超氧化物岐化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)的活性和丙二醛(MDA)的水平。将肝大叶HE染色,观察各组小鼠的肝组织病理改变。结果表明,同模型组比较,禹州漏芦乙醇提取物各剂量组均能降低小鼠血清中ALT、AST及MDA活性,升高肝组织中GSH-Px和SOD的活性,并能明显改善肝组织的病理学损伤。禹州漏芦乙醇提取物对CCl4所致小鼠急性肝损伤具有较好保肝作用,其作用可能与清除体内自由基和抗氧化的作用有关。     

A cell-free electrochemiluminescence assay for measuring beta1-integrin-ligand interactions

We have developed a cell-free assay for binding of solubilized beta1 integrins to their physiologically relevant ligands using an electrochemiluminescent detection method. The method utilizes ruthenium-conjugated monoclonal antibodies for detection of either purified integrins or, more conveniently, integrin-expressing cell lysates, which are captured on beads coated with extracellular matrix or vascular ligand proteins. For the interaction of alpha1beta1 integrin with collagen IV, a signal of 10-fold over background was generated with samples containing only 10 ng (0.05 pmol) of integrin. This interaction is cation-dependent and can be inhibited by blocking antibodies to the alpha1 subunit. The method was extended to studies of ligand binding by integrins alpha2beta1, alpha4beta1, alpha5beta1, and alpha6beta1. For each integrin-ligand pair, the specificity of the interaction was verified with neutralizing antibodies against the specific integrin. The specific binding signal correlated with the activating ability of the labeled antibody used for detection, although the ability of divalent cations (Mn2+, Mg2+, Ca2+) to support integrin-ligand binding varied dramatically among the various integrin-ligand pairs. The assay provides a simple method for investigating integrin-ligand interactions without avidity and/or signaling effects which can complicate conventional cell-based assay methods.     

Calcium plays an important role in the regulation of hepatic branched-chain 2-oxo acid dehydrogenase activity

A fetal haemoglobin variant was noted in a healthy Jamaican infant of mixed African/Chinese extraction. A two-dimensional chromatogram of the soluble tryptic peptides (Tp) showed 2 ‘new’ ones/ One was composed of the last 4 residues of the usually insoluble Tpγ41–59. To permit a tryptic split this required a change of residue γ55 Met to Lys or Arg. The other new Tp contained arginine and was in the position expected for a Tpγ41–55 (55 Arg). As the material was limited it could not be analysed. When after more than 6 years no example of Hb F Kingston had become available it was decided to describe the variant on the basis of the present evidence.     

Isolation and identification of a fucose-containing ganglioside from bovine thyroid gland

Bovine thyroid glands are known to contain a complex array of gangliosides. One of the predominant gangliosides was isolated and analyzed by gas-liquid chromatography and mass spectrometry. The carbohydrate composition was fucose, N-acetylneuraminic acid, galactose, N-acetylgalactosamine, and glucose in molar ratios of 1:1:2:1:1. The structure of the ganglioside was identified as:

     

Interleukin-1beta induces macrophage inflammatory protein-1beta expression in human hepatocytes

The investigation of factors that regulate expression of CC-chemokines, the important mediators in immune responses and inflammation processes, has an important significance in understanding the immunopathogenesis of liver diseases. We examined the role of interleukin-1beta (IL-1beta), a multifunctional cytokine, in regulating the expression of macrophage inflammatory protein (MIP)-1beta in human hepatocytes (Huh7 and HepG2). IL-1beta significantly enhanced MIP-1beta expression in these cells at both the mRNA and protein levels. Cytokine-enriched supernatants from monocyte-derived macrophage (MDM) cultures also induced MIP-1beta expression. IL-1beta is responsible for MDM supernatant-mediated up-regulation of MIP-1beta since the antibody to IL-1beta abolished MDM supernatant action. Investigation of the mechanism involved in MIP-1beta induction by IL-1beta showed that IL-1beta activated the nuclear factor kappa B (NF-kappaB) promoter in Huh7 cells. In addition, caffeic acid phenethyl ester (CAPE), a specific inhibitor of the activation of NF-kappaB, not only abolished IL-1beta-mediated NF-kappaB promoter activation, but also blocked IL-1beta-induced MIP-1beta expression. These observations suggest that IL-1beta-mediated up-regulation of MIP-1beta production in the hepatic cells may contribute a critical mechanism for continuous recruitment of inflammatory cell to liver and maintenance of inflammation.     

Dopamine release from nerve endings induced by polysialogangliosides

Polysialogangliosides but not monosialoganlioside or a neutral glycosphingolipid induce release of [³H] -dopamine from synaptosomes in presence of Ca⁺⁺, presumably by exocytosis. This effect is discussed in relation to the ability of polysialogangliosides to induce membrane fusion in chicken erythrocytes and to their behaviour in lipid monolayers. It is suggested that characteristic interactions with phosphatidylcholine involving decreases of surface potential are participating in the polysialoganglioside-induced neurotransmitter release.     

Interaction of myelin basic protein, melittin and bovine serum albumin with gangliosides, sulphatide and neutral glycosphingolipids in mixed monolayers

Some parameters that may regulate the miscibility and stability of mixed lipid-protein monolayers at the air-145 mM NaCl interface were studied employing six glycosphingolipids (acidic or neutral), three different types of proteins (soluble, extrinsic or highly amphipathic) and some phospholipids. The results obtained show that the percentage of the total area occupied by the protein at the interface is an important parameter leading to lateral phase separations; the amount and area contribution of the protein accepted in the film before the components become immiscible increase with the complexity of the polar head group of the glycosphingolipids. The interactions occur with progressive reductions of the intermolecular packing as the polar head group of the glycosphingolipid becomes more complex and this is accompanied by more negative values of the excess free energy of mixing. The lipid component seems to be the major responsible for the reduction in mean molecular area.     

人参皂甙Rb1对AD大鼠顶叶皮质β-分泌酶及PS-1表达的影响

目的探讨人参皂甙Rb1对AD大鼠顶叶皮质β-分泌酶及PS-1表达的影响。方法30只健康雄性SD大鼠,随机分为对照组、模型组和治疗组。模型组大鼠胃饲氯化铝同时腹腔注射D半乳糖2个月,对照组大鼠给予等剂量生理盐水,治疗组大鼠于造模结束后腹腔注射人参皂甙Rb14周。采用刚果红染色法观察老年斑,镀银染色法观察神经原纤维缠结,Western blot方法、免疫组化方法和图像分析技术对β-分泌酶及PS-1的表达进行检测。结果模型组与对照组相比有明显的老年斑及神经原纤维缠结形成,β-分泌酶及PS-1的表达增多（P〈0．01）;治疗组老年斑及神经原纤维缠结数量减少,β-分泌酶及PS-1的表达与模型组相比明显减少（P〈0．05）。结论AD模型大鼠顶叶皮质神经元β-分泌酶及PS-1表达水平明显上调,人参皂甙Rb1可明显改善模型动物上述蛋白的异常表达,对神经元具有明显保护和营养作用。     

Increase in dATP pool in aphidicolin-resistant mutants of mouse FM3A cells

Mutants that were resistant to aphidicolin were isolated from mutagenized mouse FM3A cells at a frequency of about 10^?6. Resistance to aphidicolin in these mutants was not due to an effect on [³H]thymidine incorporation into DNA, DNA synthesis in permeabilized cells, or DNA polymerase α.All the mutants showed a greatly increased dATP pool and decreased ability to incorporate [³H]deoxycytidine into DNA. They also showed cross-resistance to both 1-β-D-arabinofuranosyladenine and 1-β-D-arabinofuranosylcytosine.These results indicate that an enzyme involved in production of dATP or its regulation is altered in these mutants. It is suggested that dATP competes with aphidocolin at its killing site or that dATP reverses the effect of aphidicolin by some unknown mechanism $\text{in}\text{vivo}$.     

Histone deacetylase1 promotes TGF-β1-mediated early chondrogenesis through down-regulating canonical Wnt signaling

Cartilage formation during both embryonic development and bone repairing processes involves mesenchymal stem cells (MSCs) differentiation. Wnt/β-catenin signaling pathway inhibits early chondrogenesis and is down-regulated during Transforming growth factor-β1 (TGF-β1)-induced chondrogenesis. However, the regulatory molecules that participate in the process is unknown. This study was designed to investigate the underlying mechanisms that down-regulate Wnt/β-catenin pathway during chondrogenesis. TGF-β1-induced micromass cultures of C3H10T1/2 were used as chondrocyte differentiation model. Gene expression profile was detected by realtime-PCR. Regulatory role of HDAC1 on β-catenin was investigated by luciferase assay, chromatin immunoprecipitation (ChIP) assay, co-immunoprecipitation (Co-IP) assay and in vitro ubiquitination assay. In this study, we showed that HDAC1 was induced and suppressed β-catenin gene expression through direct binding to its promoter. Besides, HDAC1 could also interact with deacetylate β-catenin protein through its deacetylase domain, which causes degradation of β-catenin. Our results indicate that HDAC1 plays an important role in chondrogenesis and may represent a therapeutic target for modulation of cartilage development.