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951.
Lippa B Kauffman GS Arcari J Kwan T Chen J Hungerford W Bhattacharya S Zhao X Williams C Xiao J Pustilnik L Su C Moyer JD Ma L Campbell M Steyn S 《Bioorganic & medicinal chemistry letters》2007,17(11):3081-3086
The synthesis and biological evaluation of potent and selective inhibitors of the erbB2 kinase is presented. Based on the 4-anilinoquinazoline chemotype, the syntheses of several new series of erbB2 inhibitors are described with quinazoline and pyrido[4,3-d]pyrimidine cores. The vast majority of these compounds are found to be >100x selective over the closely related EGFR kinase. Two lead compounds are further shown to have low clearance and moderate bioavailability in rat. 相似文献
952.
Su L Zhao B Lv X Zhao J Zhang S Miao J 《Bioorganic & medicinal chemistry letters》2007,17(11):3167-3171
Previously, we found safrole oxide could promote VEC apoptosis, however, it is not known whether it can induce NSC apoptosis. It is reported that neural stem cells (NSCs) are localized in a vascular niche. But the effects of apoptosis in vascular endothelial cells (VEC) on NSC growth and differentiation are not clear. To answer these questions, in this study, we co-cultured NSCs with VECs in order to imitate the situation in vivo, in which NSCs are associated with the endothelium, and treated the single-cultured NSCs and the co-cultured NSCs with safrole oxide. The results showed that safrole oxide (10-100 microg/mL) had no effects on NSC growth. Based on these results, we treated the co-culture system with this small molecule. The results showed that the NSCs differentiation, into neurons and gliacytes was induced by VECs untreated with safrole oxide. But in the co-culture system treated with safrole oxide, the NSCs underwent apoptosis. The data suggested that when VEC apoptosis occurred in the co-culture system, the NSC survival and differentiation could not be maintained, and NSCs died by apoptosis. Our finding provided a useful tool for investigating the effect of apoptosis in vascular endothelial cells on neural stem cell survival and differentiation in vitro. 相似文献
953.
Chung JU Kim SY Lim JO Choi HK Kang SU Yoon HS Ryu H Kang DW Lee J Kang B Choi S Toth A Pearce LV Pavlyukovets VA Lundberg DJ Blumberg PM 《Bioorganic & medicinal chemistry》2007,15(18):6043-6053
A series of alpha-substituted N-(4-tert-butylbenzyl)-N'-[4-(methylsulfonylamino)benzyl]thiourea analogues have been investigated as TRPV1 receptor antagonists. alpha-Methyl substituted analogues showed potent and stereospecific antagonism to the action of capsaicin on rat TRPV1 heterologously expressed in Chinese hamster ovary cells. In particular, compounds 14 and 18, which possess the R-configuration, exhibited excellent potencies (respectively, K(i)=41 and 39.2 nM and K(i(ant))=4.5 and 37 nM). 相似文献
954.
研究了谷朊粉的酸法改性及其在新型水性涂料中的应用.改性谷朊粉除具有优良的粘结性、流动性和流平性外,还提高了与涂料乳液的相容性,解决了谷朊粉原胶在涂料使用过程中的开裂严重,使得涂料具有更优的流平性和涂膜外观. 相似文献
955.
BACKGROUND: Lipid-based vectors have been widely applied to in vivo and in vitro gene delivery. Disaccharides can effectively stabilize lipid membranes. This study examined whether disaccharides could enhance the transgene expression mediated by lipid-based vectors. METHODS: Different disaccharides were incorporated into the vectors prepared with DOTAP/protamine/DNA (LPD) or with DNA/cationic liposomes containing DOTAP, DOTAP/Chol, DOTAP/DOPE, or DC-Chol/DOPE. The levels of transgene expression and internalized plasmid of CHO cells were represented by the percentages of GFP-positive cells and the fluorescence intensity of ethidium-monoazide covalently labeled plasmid, respectively. The vectors containing either cellobiose or trehalose were also intravenously injected into mouse tail vein to investigate the potentials of in vivo applications. RESULTS: For enhancing the transgene expression, cellobiose was found to be effective for all the vectors whereas maltose decreased the effectiveness of DOTAP/Chol liposomes and LPD. For the internalization of plasmid, most disaccharides were able to increase the cellular delivery of DOTAP, DOTAP/Chol, and DOTAP/DOPE liposomes, but caused decreases in the cellular entry of DC-Chol/DOPE liposomes. An approximately linear correlation between the internalized plasmid and the transgene expression was observed for all the treatments in this study. When the vectors were administered to mouse by intravenous injection, 10-fold and 3-fold increases in the luciferase expression of lung were observed for DOTAP liposomes containing 330 mM cellobiose and trehalose, respectively. CONCLUSIONS: This study showed that using trehalose and cellobiose with a lipid-based delivery system provides a straightforward approach to effectively enhance both in vitro and in vivo transgene expression. 相似文献
956.
Novel biodegradable molecularly imprinted polymers (MIPs) based on poly(ε-caprolactone) (PCL) were prepared by combining two
important properties required of ideal biomaterials, biodegradability (with biocompatibility) and molecular recognition properties.
Acrylate or methacrylate end-capped PCL macromers were synthesized through the reaction of PCL diol or triol with acryloyl
or methacryloyl chloride. The synthesis of acrylate or methacrylate end-capped macromers was confirmed using FT-IR and H NMR
spectroscopic techniques. These macromers were used to prepare biodegradable crosslinked networks by photopolymerization with
functional monomer (acrylic acid) and a model template (theophylline). The theophylline-imprinted polymer showed higher binding
capacity for theophylline compared with non-imprinted polymer (NIP), and also showed selectivity for theophylline over caffeine
(similar structure molecules). PCL-based MIP degraded 8% of the initial weight in 30 days in phosphate-buffered saline (PBS)
solution (pH 7.4) and over 90% of the initial weight within 24 h in 1 N NaOH at 37°C. 相似文献
957.
All jumping spiders have unique, complex eyes with exceptional spatial acuity and some of the most elaborate vision-guided predatory strategies ever documented for any animal of their size. However, it is only recently that phylogenetic techniques have been used to reconstruct the relationships and key evolutionary events within the Salticidae. Here, we used data for 35 species and six genes (4.8 kb) for reconstructing the phylogenetic relationships between Spartaeinae, Lyssomaninae and Salticoida. We document a remarkable case of morphological convergence of eye ultrastructure in two clades with divergent predatory behaviour. We, furthermore, find evidence for a stepwise, gradual evolution of a complex predatory strategy. Divergent predatory behaviour ranges from cursorial hunting to building prey-catching webs and araneophagy with web invasion and aggressive mimicry. Web invasion and aggressive mimicry evolved once from an ancestral spartaeine that was already araneophagic and had no difficulty entering webs due to glue immunity. Web invasion and aggressive mimicry was lost once, in Paracyrba, which has replaced one highly specialized predation strategy with another (hunting mosquitoes). In contrast to the evolution of divergent behaviour, eyes with similarly high spatial acuity and ultrastructural design evolved convergently in the Salticoida and in Portia. 相似文献
958.
Effects of culture conditions on osteogenic differentiation in human mesenchymal stem cells 总被引:1,自引:0,他引:1
Song SJ Jeon O Yang HS Han DK Kim BS 《Journal of microbiology and biotechnology》2007,17(7):1113-1119
Human bone marrow-derived mesenchymal stem cells (hBMMSCs) must differentiate into osteogenic cells to allow for successful bone regeneration. In this study, we investigated the effects of different combinations of three soluble osteogenic differentiation-inducing factors [L-ascorbic acid (AC), beta-glycerophosphate (betaG), and bone morphogenic protein-2 (BMP-2)] and the presence of a hydroxyapatite (HA) substrate on hBMMSC osteogenic differentiation in vitro. hBMMSCs were cultured in medium containing various combinations of the soluble factors on culture plates with or without HA coating. After 7 days of culture, alkaline phosphatase (ALP) activity, calcium deposition, and osteoprotegerin (OPG) and osteopontin (OPN) expression were measured. The effects of individual and combined factors were evaluated using a factorial analysis method. BMP-2 predominantly affected expression of early markers of osteogenic differentiation (ALP and OPG). HA had the highest positive effect on OPN expression and calcium deposition. The interaction between AC, betaG, and HA had the second highest positive effect on ALP activity. 相似文献
959.
960.