Hedgehog signaling in vertebrate eye development: a growing puzzle

The vertebrate retina has been widely used as a model to study the development of the central nervous system. Its accessibility and relatively simple organization allow analysis of basic mechanisms such as cell proliferation, differentiation and death. For this reason, it could represent an ideal place to solve the puzzle of Hh signaling during neural development. However, the extensive wealth of data, sometimes apparently discordant, has made the retina one of the most complicated models for studying the role of the Hh cascade. Given the complexity of the field, a deep analysis of the data arising from different animal models is essential. In this review, we will compare and discuss all reported roles of Hh signaling in eye development to shed light on its multiple functions.Received 26 September 2003; received after revision 13 November 2003; accepted 19 November 2003     

活性初乳素对喉癌细胞增殖的影响

采用活性初乳素替代血清培养细胞的方法，观察了不同浓度的活性初乳素对喉癌细胞（ＨＥｐ－２）增殖的影响，并观察了细胞生长曲线的变化。结果表明：活性初乳素浓度较低时，随其浓度的增高对细胞增殖的刺激作用增大，当活性初乳素浓度为２％时刺激作用最大（ｐ〈０．００１），而高浓度的活性初乳素（４％、８％、１６％）对细胞增殖有明显的抑制作用（ｐ〈０．０１）；培养在无血清培液中的细胞不增殖，在含１０％血清或０．２％活     

Immunostimulatory properties of a novel polyphosphoramidate based on stearyl tyrosine

The immunostimulatory property of a synthetic polyphosphoramidate based on stearyl tyrosine (PPST) is described. The immunostimulatory activity of this negatively charged polymer was investigatedin vitro through examining the effect on the mitogen-induced lymphocytes proliferation by a tetrazolium-based colormetric assay and also through studying the primary plaque-forming cells (IgM PFC) responses of Balb/c mice after the intraperitoneal (i.p.) injection of the polymer with sheep red blood cells (SRBC). PPST exhibits specific and high immunostimulatory activityin vitro by the stimulation on lipopolysaccharide(LPS)-induced murine B-cells proliferation, which is probably due to the interaction between the polymer with LPS-responding B lymphocytes. This polymer also makes a significant increase of single antibody producing cells. The result shows that the stimulation rate to IgM PFC response of Balb/c mice achieved 77.9% (p<0.01) when 160 mg/kg of PPST was injected 4 h before with SRBC. Supported by the National Natural Science Foundation of China and Research Laboratories of Natural and Biomimetic Drugs of Beijing Medical University Zhuo Renxi: born in Feb. 1931, Professor     

细胞维持离子高(或低)浓度的随机过程论模型

本文建立了细胞维持离子高(或低)浓度的随机过程论模型。模型的随机差分方程是: 其中对于对于作者根据此模型,对细胞内离子浓度的均值和涨落做了计算。该模型是与实验事实相吻合的,同时它还揭示出细胞的自组织功能。本文工作是建立离子运动模型研究的一个新方向。     

太白米细胞培养研究简报

把太白米小鳞茎基部0．1～0．5mm处横切口，接种于MS附加激素的培养基上，小鳞茎脱分化产生愈伤组织.切割愈伤组织经团体继代培养、细胞悬浮培养，能得到大量太白米细胞培养物．     

Effect of dipyridamole and adenosine monophosphate on cell proliferation in the hemopoietic tissue of normal and gamma-irradiated mice

Combined treatment with dipyridamole and adenosine monophosphate enhances cell proliferation in the hemopoietic tissue of normal and gamma-irradiated mice. This effect can be explained by the elevation of extracellular adenosine, and the receptor-mediated activation of the cell adenylate cyclase system.     

Cell-to-cell coupling assayed by means of electrical measurements

Summary The importance of electrical measurements in the evaluation of cell-to-cell coupling in heart muscle was discussed. The presence of gap junctions in heart and smooth muscle, and the implications of this for electrical synchronization and healing-over, was emphasized. Moreover, the modulation of junctional resistance by Ca, protons and cAMP was reviewed.Nur allein der Mensch Vermag das Unmögliche, Er unterscheidet, Wählet und richtet; Er kann dem Augenblick Dauer verleihen. Goethe     

对妊娠期巨幼红细胞性贫血造血过程中无丝分裂的一些观察

对直接细胞分裂的研究已有百余年历史,直接分裂究属正常繁殖过程,抑为异常或病理性现象,其说不一,尚难定论。本文在一例重症妊娠期巨幼红细胞性贫血患者的骨髓涂片中发现巨幼红细胞的直接核分裂现象,除了通常的直接核分裂外,尚存在罕见的细胞‘改组’(新核在老核内的形成)及核内无丝分裂。笔者在另一例慢性淋巴细胞白血病患者的骨髓涂片中,亦曾观察到细胞‘改组’现象。因此,笔者认为直接核分裂应属病理性造血过程,即当造血急需时,在通常病理造血过程的同时,亦可出现各型直接分裂以做为造血的补充。这一现象的发现具有造血理论和临床实际意义。     

A unifying model of the cell proliferation emphasizing plasma membrane fluxes

Summary The regulation of cellular growth and proliferation is perhaps the most investigated and elusive problem in cell biology and seems to be possible to solve from almost any angle of study chosen. Among the non-systemic factors that have been discussed are genetic damage, genomic control, regulation by stimulatory and inhibitory peptide factors such as EGF, chalones, and fibronectin, protein kinase activition with tyrosine phosphorylation, adenylylcyclase and cAMP, cGMP, membrane perturbations and specifically in tumours the failure of the Pasteur effect in control of glycolysis, excessive membrane ATPase activity, and excessive hydrolytic and proteolytic activities at the cell surface. This article focusses on the central role of fluxes within the plasma membrane and re-examines the possibility that changes of flux of metabolites, ions, and reducing equivalents may be the common denominator regulating cellular proliferation.