IN VIVO EFFECTS OF CARDIOTROPHIN-1

Cardiotrophin-1 (CT-1) is a recently discovered cytokine that was isolated based on its ability to induce cardiac myocyte hypertrophy in vitro. In this study, the effects of chronic administration of CT-1 to mice (0.5 or 2 μg by intraperitoneal injection, twice a day for 14 days) were determined. A dose-dependent increase in both the heart weight and ventricular weight to body ratios was observed in the treated groups. The body weights of the animals were unaffected. These results indicate that CT-1 can induce cardiac hypertrophy in vivo. CT-1 was not specific for the heart, however. It stimulated the growth of the liver, kidney, and spleen, and caused atrophy of the thymus. CT-1 administration also increased the platelet counts by 70%, with no change in mean platelet volume. Red blood cell counts were increased in the treated animals, and there was a concomitant increase in haemoglobin concentration. Thus, CT-1 has a broad spectrum of biological activities in vivo. This observation is consistent with previous in-vitro findings showing that the mRNA for CT-1 is expressed in several tissues, and that CT-1 can function through binding to the leukaemia inhibitory factor (LIF) receptor and signalling through the gp130 pathway.     

K、Na、Ca、Mg 4种元素在疏叶骆驼刺体内含量分布特点的研究

 此项工作在新疆平原荒漠区盐化草甸带进行。研究结果显示出K、Na、Ca、Mg 4种元素在植物体内不同器官的含量分布特点和各个器官中不同元素间的含量关系。同时表明这4种元素在植物体不同器官中具有不同的作用。对于K、Na元素,地上部器官尤其叶片中含量水平反映出器官具有较强的留K排Ns的选择性元素的分配机制。     

Nerve Growth Factor as a Mitogen for a Pancreatic Carcinoid Cell Line

Abstract: Carcinoid tumors are a group of neuroendocrine neoplasms distributed widely throughout the body but most commonly occurring in the gut. These tumors retain many characteristics of their neural crest origin, including secretion of neuroactive peptides and responsiveness to neurotrophic substances. Nerve growth factor (NGF), a neurotrophic protein involved in maintenance and differentiation of peripheral sympathetic and sensory neurons, regulates growth of several neural tumor cells by inducing a differentiated phenotype and subsequent inhibition of cell growth rate. We examined the actions of NGF in a functioning human pancreatic carcinoid cell line (termed BON). NGF has no effect on the cytoarchitecture or constitutive secretion of bioamines in this carcinoid cell line. NGF, however, stimulates the in vitro cellular proliferation of BON cells. BON cells possess mRNA for the NGF receptors (p75^LNGFR and p140^trkA) and membrane-associated tyrosine kinase activity is increased in response to NGF. Both the mitogenic activity of NGF, as well as the receptor-linked tyrosine kinase activity, can be abrogated in BON cells by the trkA inhibitor K-252a and specific anti-NGF antibody. Our studies demonstrate that NGF is a mitogen for this carcinoid cell line without effect on cellular phenotype or cytoarchitecture. NGF may play a role in the development and progression of human carcinoid tumors.     

Effect of Root Zone Temperature on the Mineral Composition of Xylem Sap and Plasma Membrane K+-Mg++-ATPase Activity of Grafted-Cucumber and -Figleaf Gourd Root Systems

Cucumber (Cucumis sativus L.) seedlings were grafted onto cucumber-(CG) or figleaf gourd- (FG, Cucurbita ficifolia Bouché)seedlings in order to determine the effect of solution temperature(12, 22, and 32°C) on the mineral composition of xylem sapand the plasma membrane K⁺-Mg⁺⁺-ATPase activities of the roots.Low solution temperature (12°C) lowered the concentrationof NO^–₃ and H₂PO^–₄ in xylem sap of CG plants butnot of FG plants. Concentrations of K⁺, Ca⁺⁺ and Mg⁺⁺ in xylemsap were less affected than anions by solution temperature.The plasma membrane of FG plants grown in 12°C solutiontemperature showed the highest K⁺- Mg⁺⁺-ATPase activity at allATP concentrations up to 3 mM and at low reaction temperatureup to 12°C, indicating resistance of figleaf gourd to lowroot temperature. (Received December 27, 1994; Accepted March 10, 1995)     

Prostaglandin H Synthetase-Mediated Metabolism of Dopamine: Implication for Parkinson's Disease

Abstract: Differences in prostaglandin H synthetase (PHS) activity in the substantia nigra of age- and post-mortem interval-matched parkinsonian, Alzheimer's, and normal control brain tissue were assessed. Prostaglandin E₂ (PGE₂, an index of PHS activity) was higher in substantia nigra of parkinsonian brain tissue than Alzheimer's or control tissue. Incubation of substantia nigra slices with arachidonic acid (AA) increased PGE₂ synthesis. Dopamine stimulated PHS synthesis of PGE₂. [³H]Dopamine was activated by PHS to electrophilic intermediate(s) that covalently bound to DNA, microtubulin protein, bovine serum albumin, and sulfhydryl reagents. When AA was replaced by hydrogen peroxide, PHS/H₂O₂-supported binding proceeded at rates similar to those observed with PHS/AA. Indomethacin and aspirin inhibited AA-mediated cooxidation of dopamine but not H₂O₂-mediated metabolism. PHS-mediated metabolism of dopamine was not affected by monoamine oxidase inhibitors. Substrate requirements and effects of specific inhibitors suggest cooxidation of dopamine is mediated by the hydroperoxidase activity of PHS. ³²P-postlabeling was used to detect dopamine-DNA adducts. PHS/AA activation of dopamine in the presence of DNA resulted in the formation of five dopamine-DNA adducts, i.e., 23, 43, 114, 70, and 270 amol/µg DNA. DNA adduct formation was PHS, AA, and dopamine dependent. PHS catalyzed cooxidation of dopamine in dopaminergic neuronal degeneration is discussed.     

甘蔗细平象的研究

甘蔗细平象Trockorhopalus humeralis Chevrolat是云南甘蔗上的一种毁灭性地下害虫,以幼虫和成虫在地下蔗头内为害,为害期8-10个月。据1989年调查,受害蔗每亩损失500-3000kg,严重的无收。此虫1年发生1代,以成虫在蔗头内越冬,有喜湿性,不能飞翔,主要通过沟河流水传播。在河川坝地,沙壤土中虫口较多;宿根年限越长的甘蔗受害越重。建议蔗稻轮作;缩短甘蔗宿根年限;早春翻挖有虫蔗蔸烧毁;结合新植蔗下种,宿根蔗松蔸培土施用甲基异柳磷或铁灭克等颗粒杀虫剂进行防治。     

鱼腥藻HB1017株化能异养生长的研究

以葡萄糖和蔗糖为碳源,检测了六株（种）鱼腥藻的化能异养生产能力。其中鱼腥藻ＨＢ１０１７株化能异养生长较快,鱼腥藻ＨＢ０株化能异养生长缓慢,其余四种鱼腥藻不能进行化能异养生长。鱼腥藻ＨＢ１０１７株能利用果糖、葡萄糖、蔗糖为底物进行化能异养生长,但生长速率依次递减,差别显著。８磅湿热灭菌的果糖和蔗糖,与过滤灭菌的相比,只能维持低得多的化能异养生长速率。然而,８磅湿热灭菌的葡萄糖能维持比过滤法灭菌的高得     

生态环境对白芷产量质量的影响

生态环境对白芷产量质量的影响陈兴福,丁德蓉,刘岁荣,卢进,黄文秀（四川省中医药研究院药物种植研究所,南川６４８４０８）ＥｆｆｅｃｔｏｆＥｃｏ－ＥｎｖｉｒｏｎｍｅｎｔｏｎＤａｈｕｒｉａｎＡｎｇｅｌｉｃａＹｉｅｌｄａｎｄＩｔｓＱｕａｌｉｔｙ￥ＣｈｅｎＸｉ...