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21.
Richards SJ von Geldern TW Jacobson P Wilcox D Nguyen P Ohman L Osterlund M Gelius B Grynfarb M Goos-Nilsson A Wang J Fung S Kalmanovich M 《Bioorganic & medicinal chemistry letters》2006,16(23):6086-6090
A series of potent steroidal glucocorticoid receptor antagonists has been discovered. After conjugation to cholic acid, the compounds retained an affinity for GR in vitro and had modest in vivo efficacy. 相似文献
22.
In most eukaryotes, telomeric DNA consists of repeats of a short motif that includes consecutive guanines and may hence fold into G-quadruplexes. Budding yeasts have telomeres composed of longer repeats and show variation in the degree of repeat homogeneity. Although telomeric sequences from several organisms have been shown to fold into G-quadruplexes in vitro, surprisingly, no study has been dedicated to the comparison of G-quadruplex folding and stability of known telomeric sequences. Furthermore, to our knowledge, folding of yeast telomeric sequences into intramolecular G-quadruplexes has never been investigated. Using biophysical and biochemical methods, we studied sequences mimicking about four repetitions of telomeric motifs from a variety of organisms, including yeasts, with the aim of comparing the G-quadruplex folding potential of telomeric sequences among eukaryotes. G-quadruplex folding did not appear to be a conserved feature among yeast telomeric sequences. By contrast, all known telomeric sequences from eukaryotes other than yeasts folded into G-quadruplexes. Nevertheless, while G(3)T(1-4)A repeats (found in a variety of organisms) and G(4)T(2,4) repeats (found in ciliates) folded into stable G-quadruplexes, G-quadruplexes formed by repetitions of G(2)T(2)A and G(2)CT(2)A motifs (found in many insects and in nematodes, respectively) appeared to be in equilibrium with non-G-quadruplex structures (likely hairpin-duplexes). 相似文献
23.
Priscila R Moreira Marcos A Maioli Hyllana CD Medeiros Marieli Guelfi Flávia TV Pereira Fábio E Mingatto 《Biological research》2014,47(1)
Background
The liver is an important organ for its ability to transform xenobiotics, making the liver tissue a prime target for toxic substances. The carotenoid bixin present in annatto is an antioxidant that can protect cells and tissues against the deleterious effects of free radicals. In this study, we evaluated the protective effect of bixin on liver damage induced by carbon tetrachloride (CCl4) in rats.Results
The animals were divided into four groups with six rats in each group. CCl4 (0.125 mL kg-1 body wt.) was injected intraperitoneally, and bixin (5.0 mg kg-1 body wt.) was given by gavage 7 days before the CCl4 injection. Bixin prevented the liver damage caused by CCl4, as noted by the significant decrease in serum aminotransferases release. Bixin protected the liver against the oxidizing effects of CCl4 by preventing a decrease in glutathione reductase activity and the levels of reduced glutathione and NADPH. The peroxidation of membrane lipids and histopathological damage of the liver was significantly prevented by bixin treatment.Conclusion
Therefore, we can conclude that the protective effect of bixin against hepatotoxicity induced by CCl4 is related to the antioxidant activity of the compound. 相似文献24.
Phuong-Thao Nguyen-Thi Quoc Phong Le Volker R. Stoldt Ngoc Quyen Tran Anh Tho Le Khon Huynh 《Molecular & cellular biomechanics : MCB》2020,17(3):113-118
Fibrillar fibronectin (FFN) is a biological active form of FN which form
linear and branched meshwork around cells and support cellular activities. Previous studies have demonstrated that shear stress can induce cell-free FN fibrillogenesis. In this study, we further examined the effect of shear stress conditions on
morphology of formed FFN and preliminarily looked for relationship between
FFN’s morphology and cell adhesion. Plasma FN at 50 µg/ml was perfused
through channel slides at shear rates of 500 s-1 or 4000 s-1. Our results showed
that there were four FFN structures formed: (1) FN nodules, (2) fibril in different
sizes (3) with or without nodule attachment, and (4) fibrillar matrix. At 4000 s-1,
FFN fibrils was formed within the first 10 min and reached the highest surface
coverage only after 20 min. In contrast, FFN formation was significant more
slowly at 500 s-1 at which only FN nodules and small fibrils were formed. Platelets bound on thin layer of FN and rarely found on large FN fibrils. In contrast,
fibroblast stretched their shape on platform of FFN matrix and bound actively
to all types of FFNs. Taken together, our data suggests a morphological dependent
biological activity of FFN. 相似文献
25.
Nguyen Phong Chau 《Mathematical biosciences》1985,74(2):199-218
We consider a general mamillary model with a central compartment (compartment 1) and n?1 peripheral compartments, each bidirectionally connected to the first. Elimination is allowed from any compartment and effectively occurs from the system. With input introduced into an arbitrary compartment and measurement performed in an arbitrary compartment, explicit equations are given to derive the parameters of the model from the input-output procedure. The calculations include essentially the determination of the roots of a polynomial plus some elementary algebra. If input and measurement are performed in the same compartment, then a set of 2n elementary combinations of the model parameters can be uniquely determined. However, the model parameters themselves can only be localized, each within an interval. These intervals are explicitly calculated and their width discussed. 相似文献
26.
Nguyen Phong Chau 《Mathematical biosciences》1985,76(2):185-206
Resolution of kinetic equations and parameter identification are discussed for n-compartment linear catenary models with elimination allowed from any compartment. For a given input, general formulas are derived to describe the tracer amount in any compartment as a function of the model parameters. Conversely, explicit procedures are given to identify the model parameters when the concentration-time curve is known in one arbitrary compartment, the tracer being injected into the same compartment. In this inverse problem, the solution is not unique: the model transfer rate constants can only be localized in a finite set of intervals. 相似文献
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28.
Terramani TT Eton D Bui PA Wang Y Weaver FA Yu H 《In vitro cellular & developmental biology. Animal》2000,36(2):125-132
Summary The purpose of this study is to identify optimal culture conditions to support the proliferation of human macrovascular endothelial
cells. Two cell lines were employed: human saphenous vein endothelial cells (HSVEC) and human umbilical vein endothelial cells
(HUVEC). The influence of basal nutrient media (14 types), fetal bovine serum (FBS), and mitogens (three types) were investigated
in relation to cell proliferation. Additionally, a variety of extracellular matrix (ECM) substrate-coated culture dishes were
also tested. The most effective nutrient medium in augmenting cell proliferation was MCDB 131. Compared to the more commonly
used M199 medium, MCDB 131 resulted in a 2.3-fold increase in cell proliferation. Media containing 20% FBS increased cell
proliferation 7.5-fold compared to serum-free media. Among the mitogens tested, heparin (50 μg/ml) and endothelial cell growth
supplement (ECGS) (50μg/ml) significantly improved cell proliferation. Epithelial growth factor (EGF) provided no improvement
in cell proliferation. There were no statistical differences in cell proliferation or morphology when endothelial cells were
grown on uncoated culture plates compared to plates coated with ECM proteins: fibronectin, laminin, gelatin, or collagen types
I and IV. The culture environment yielding maximal HSVEC and HUVEC proliferation is MCDB 131 nutrient medium supplemented
with 2 mM glutamine, 20% FBS, 50 μg/ml heparin, and 50 μg/ml ECGS. The ECM substrate-coated culture dishes offer no advantage. 相似文献
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30.
Rapid propagation of agave by in vitro tissue culture 总被引:1,自引:0,他引:1
L. T. Binh L. T. Muoi H. T. K. Oanh T. D. Thang D. T. Phong 《Plant Cell, Tissue and Organ Culture》1990,23(1):67-70
A procedure for rapid propagation of Agave (A. cantala Roxb., A. fourcroydes Lem. and A. sisalana Perrine, (Agavaceae) have been developed. The explants were excised from stolon plantlets, sterilized and cultivated on Murashige and Skoog (MS) basal medium containing 2% sucrose, 10% coconut water and 0.8% agar. The addition of following combination of growth substances—0.075 mgl-1 naphthalenacetic acid (NAA)+0.1 mgl-1 indolylbutyric acid (IBA)+0.5 mgl-1 kinetin (KIN) caused an extensive proliferation of multiple shoot primordia. Subcultures of these on the same medium were successful for the multiplication with an index of 3–4 times per 4 weeks subculture period. Shoots were rooted on hormone free MS medium and then transferred into a sand bed for acclimation before field planting. 相似文献