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71.
Transforming growth factor alpha (TGFα) is a close relative of epidermal growth factor (EGF), the first polypeptide mitogen discovered in 1962 (Cohen, 1962). TGFα, like EGF, exerts its effect on cells through binding to the EGF-Receptor (EGF-R). Here we review the molecular and cell biology of TGFα before proceeding to describe our own work on signaling molecules induced in response to activation of the EGF-R. 相似文献
72.
Ascorbic acid increases the yield of dopaminergic neurons derived from basic fibroblast growth factor expanded mesencephalic precursors 总被引:16,自引:0,他引:16
CNS precursors derived from E12 rat mesencephalon proliferate in the presence of basic fibroblast growth factor and differentiate in vitro into functional dopaminergic neurons, which upon transplantation alleviate behavioral symptoms in a rat model of Parkinson's disease. Here we show that the efficiency of dopaminergic differentiation decreases in the mesencephalic precursors that were proliferated or passaged for extended periods in vitro. Ascorbic acid treatment restored dopaminergic differentiation in these precursors and led to a greater than 10-fold increase in dopamine neuron yield compared with untreated cultures. The effect of ascorbic acid was stereospecific and could not be mimicked by any other antioxidants. The expression of sodium-dependent vitamin C transporter, a recently identified stereospecific ascorbic acid transporter, was maintained in mesencephalic precursors for extended in vitro periods. Pre-treatment of in vitro expanded mesencephalic precursors with ascorbic acid might facilitate the large-scale generation of dopaminergic neurons for clinical transplantation. 相似文献
73.
Rec8p, a meiotic recombination and sister chromatid cohesion phosphoprotein of the Rad21p family conserved from fission yeast to humans 总被引:11,自引:0,他引:11 下载免费PDF全文
74.
Three antimicrobial compounds produced by Bacillus sp. strain CS93 isolated from pozol were identified by using high-performance liquid chromatography and mass spectrometry. The three compounds were iturin, bacilysin, and chlorotetaine. Production of these compounds by CS93 could account for the medicinal properties attributed to pozol. 相似文献
75.
Watson JL Ansari S Cameron H Wang A Akhtar M McKay DM 《American journal of physiology. Gastrointestinal and liver physiology》2004,287(5):G954-G961
A characteristic of many enteropathies is increased epithelial permeability, a potentially pathophysiological event that can be evoked by T helper (Th)-1 (i.e., IFN-gamma) and Th2 (i.e., IL-4) cytokines and bacterial infection [e.g., enteropathogenic Escherichia coli (EPEC)]. The green tea polyphenol (-)-epigallocatechin gallate (EGCG) has immunosuppressive properties, and we hypothesized that it would ameliorate the increased epithelial permeability induced by IFN-gamma, IL-4, and/or EPEC. EGCG, but not the related epigallocatechin, completely prevented the increase in epithelial (i.e., T84 cell monolayer) permeability caused by IFN-gamma exposure as gauged by transepithelial resistance and horseradish peroxidase flux; EGCG did not alleviate the barrier disruption induced by IL-4 or EPEC. IFN-gamma-treated T84 and THP-1 (monocytic cell line) cells displayed STAT1 activation (tyrosine phosphorylation on Western blot analysis, DNA binding on EMSA) and upregulation of interferon response factor-1 mRNA, a STAT1-dependent gene. All three events were inhibited by EGCG pretreatment. Aurintricarboxylic acid also blocked IFN-gamma-induced STAT1 activation, but it did not prevent the increase in epithelial permeability. Additionally, pharmacological blockade of MAPK signaling did not affect IFN-gamma-induced epithelial barrier dysfunction. Thus, as a potential adjunct anti-inflammatory agent, EGCG can block STAT1-dependent events in gut epithelia and monocytes and prevent IFN-gamma-induced increased epithelial permeability. The latter event is both a STAT1- and MAPK-independent event. 相似文献
76.
77.
A porcine adult ICU model would be useful for several avenues of investigation relevant to the care of critically ill patients. The purpose of the experiments reported here was to test the feasibility of such a model, using healthy swine. Swine (n = 4; body weight, 76 +/- 5 kg) were instrumented with endotracheal, bladder, and central arterial and venous catheters, and were admitted to the intensive care unit (ICU) while undergoing mechanical ventilation under the continuous care of nurses. Cardiopulmonary parameters were monitored continuously, and serum biochemical parameters were measured intermittently. Survival was seven days in subject 1 and five and a half days in subject 2. Subjects 3 and 4 survived an abbreviated protocol (44 and 41 h, respectively). Care of the subjects was complicated by iatrogenic hemorrhage (n = 3), pneumonia (n = 2), and acute respiratory distress syndrome (n = 1). One subject was free of complications. Critically ill swine > or = 70 kg can survive mechanical ventilation in the ICU for up to seven days. When iatrogenic injury occurs, swine respond well to clinical care protocols. Further testing is needed to develop a reproducible model and determine whether healthy swine can survive the ICU environment for longer than 41 h. 相似文献
78.
Stem cell biology and neurodegenerative disease 总被引:5,自引:0,他引:5
McKay RD 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2004,359(1445):851-856
The fundamental basis of our work is that organs are generated by multipotent stem cells, whose properties we must understand to control tissue assembly or repair. Central nervous system (CNS) stem cells are now recognized as a well-defined population of precursors that differentiate into cells that are indisputably neurons and glial cells. Work from our group played an important role in defining stem cells of the CNS. Embryonic stem (ES) cells also differentiate to specific neuron and glial types through defined intermediates that are similar to the cellular precursors that normally occur in brain development. There is convincing evidence that the differentiated progeny of ES cells and CNS stem cells show expected functions of neurons and glia. Recent progress has been made on three fundamental developmental processes: (i) cell cycle control; (ii) the control of cell fate; and (iii) early steps in neural differentiation. In addition, our work on CNS stem cells has developed to a stage where there are clinical implications for Parkinson's and other degenerative disorders. These advances establish that stem cell biology contributes to our understanding of brain development and has great clinical promise. 相似文献
79.
Malachy McCann Barry Coyle Sinead McKay Paul McCormack Kevin Kavanagh Michael Devereux Vickie McKee Paula Kinsella Robert O'Connor Martin Clynes 《Biometals》2004,17(6):635-645
The Cu(II) and Ag(I) complexes, [Cu(phendio)3](ClO4)24H2O and [Ag(phendio)2]ClO4 (phendio = 1,10-phenanthroline-5,6-dione), are prepared in good yield by reacting phendio with the appropriate metal perchlorate salt. The X-ray crystal structure of the Ag(I) complex shows it to have a pseudo tetrahedral structure. `Metal-free' phendio and the Cu(II) and Ag(I) phendio complexes strongly inhibit the growth of the fungal pathogen Candida albicans, and are more active than their 1,10-phenanthroline analogues. The simple Ag(I) salts, AgCH3CO2, AgNO3 and AgClO4.H2O display superior anti-fungal properties compared to analogous simple Cu(II) and Mn(II) salts, suggesting that the nature of the metal ion strongly influences activity. Exposing C. albicans to `metal-free' phendio, simple Ag(I) salts and [Ag(phendio)2]ClO4 causes extensive, non-specific DNA cleavage. `Metal-free' phendio and [Ag(phendio)2]ClO4 induce gross distortions in fungal cell morphology and there is evidence for disruption of cell division. Both drugs also exhibit high anti-cancer activity when tested against cultured mammalian cells. 相似文献
80.