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1.
We report the design and synthesis of enzyme-responsive nanofibers. The fibers are composed of self-assembled hydrophobic beta-sheet peptides incorporating protease-sensitive domains, fluorescent reporters, and hydrophilic poly(ethylene glycol) (PEG) units. Using urokinase plasminogen activator (uPA) as a model system, nanofibers were developed to release fluorescent fragments upon uPA incubation. These protease-sensitive nanofibers may have considerable biomedical applications as diagnostic sensors or for protease-assisted drug deliveries.  相似文献   

2.
In this investigation, the fabrication, physico-chemical and biological characterization of a novel smart hydrogel had been evaluated for its potentials in effective controlling protein delivery. The hydrophilic pachyman-based hydrogel was generated facilely by crosslinking hydrosoluble carboxymethyl pachyman (CMP) with epichlorohydrin (ECH). The ECH concentration possessing maximum (99.7%) encapsulation efficiency and the most appropriate swelling characteristics was found to be 1.25% (w/v). The resultant hydrogel exhibited swelling ratios most favorable for drug release in simulated intestinal media. It could release two model protein drugs (bovine serum albumin and lysozyme) in the controlled manner and with full preservation of the protein stability and enzymatic activity. Importantly, the ECH-CMP hydrogel was confirmed to be biocompatible and biodegradable. From these findings, we were able to conclude that the synthesized pachyman-based hydrogel would be a promising delivery carrier candidate for site-specific delivery of protein drugs.  相似文献   

3.
Book reviewed in this article:
S nowdon , C h . T.; B rown , C h . H.; P etersen , M. R. (eds.): Primate Communication
M oynihan , M.; R odaniche , A. F.: The Behaviour and Natural History of the Caribbean Reef Squid Sepioteuthis sepioidea
M ossakowski , D.; R oth , G. (ed.): Environmental Adaptation and Evolution
S impson , G. G.: Splendid isolation  相似文献   

4.
The urokinase-type plasminogen activator (uPA) interacts with its receptor (uPAR) to promote local proteolysis as well as cellular proliferation and migration. These functions contribute to the pathogenesis of lung inflammation and remodeling as well as the growth and invasiveness of lung neoplasms. In this study, we sought to determine if uPA alters its own expression in lung epithelial cells. Using immunoprecipitation and Western and Northern blotting techniques, we found that uPA treatment enhanced uPA expression in Beas2B lung epithelial cells in a time- and concentration-dependent manner. The induction of uPA expression is mediated through its cell surface receptor uPAR and does not require uPA enzymatic activity. The amino-terminal fragment of uPA, lacking the catalytic domain, is sufficient to induce uPA expression. The serine protease plasmin and the protease inhibitor aprotinin failed to alter uPA-mediated uPA expression, whereas alpha-thrombin potentiated the response. Pretreatment of Beas2B cells with a tyrosine kinase inhibitor, herbimycin, suggests that activation of tyrosine kinase(s) is involved in the uPA-mediated uPA expression. Induction of uPA expression by exposure of lung-derived epithelial cells to uPA is a newly defined pathway by which this protease could influence expression of local fibrinolytic activity and other uPA-dependent cellular responses germane to lung inflammation or neoplasia.  相似文献   

5.
S tephan , H.; B aron , G.; F rahm , H. D.: Comparative Brain Research in Mammals.
S uzuki , D. T.; G riffiths , A. J. F.; M iller , J. H.; L ewontin , R. C.: G enetik. Übersetzt von S. A chten und P. B öhm .
K ämpfe , L othar (ed.): Evolution und Stammesgeschichte der Organismen. Bearbeitet von 5 Fachwissenschaftlem. 3., neubearbeitete und erweiterte Auflage.  相似文献   

6.
F rost , D. R.; E theridge , R.: A Phylogenetic Analysis and Taxonomy of Iguanian Lizards (Reptilia: Squamata).
C lutton -B rock , T. H. (ed.): Reproductive success. Studies of individual variation in contrasting breeding systems.
H armelin -V ivien , M.; B ourlière , F. (eds.): Vertebrates in Complex Tropical Systems. Ecological Studies
E lsner , N.; S inger , W. (eds.): Dynamics and Plasticity in Neuronal Systems.
G roves , C olin P.: A Theory of Human and Primate Evolution.
E benman , B.; P ersson , L. (eds.): Size structured populations - ecology and evolution.  相似文献   

7.
Hydrogels present an attractive alternative to nanoscale block copolymer aggregates and microscale resin beads as potential asystemic serum cholesterol reduction materials. Not only would the oral delivery of these materials be more pleasant than the sand-like bile salt anion sequestrant beads but also the hydrogel preparation is much simpler than the copolymer aggregate analogues [Cameron, N. S.; Eisenberg, A.; Brown, G. R. Biomacromolecules 2002, 3, 116-123. Cameron, N. S.; Eisenberg, A.; Brown, G. R. Biomacromolecules 2002, 3, 124-132]. Our goal was to explore these materials building on our experience with bulk resins and self-assembled copolymers. In this paper, following a brief introduction to hydrogels and their application to hypercholesterolemia, the synthesis, characterization, and preliminary glycocholate binding properties of poly(N,N,N-trimethylammoniumalkyl acrylamide chloride)gel are presented [Cameron, N. S.; Eisenberg, A.; Brown, G. R. Polym. Preprints 2002, 43, 771-772].  相似文献   

8.
目的:研究肺泡巨噬细胞(NR8383)不同蛋白酶体激活程度对内质网应激的影响。方法:构建UbG76V-GFP融合蛋白,将含有UbG76V-GFP的质粒导入NR8383细胞,筛选出可稳定表达UbG76V-GFP的细胞系,通过蛋白酶体抑制剂(MG132)、蛋白酶体激活剂(阿霉素)干预蛋白酶体活性。荧光显微镜观察不同蛋白酶体活性下大鼠肺泡巨噬细胞在缺氧复氧2 h、4 h、6 h时蛋白酶体活性,Western blot及PCR技术检测不同蛋白酶体活性下大鼠肺泡巨噬细胞在缺氧复氧2 h、4 h、6 h时泛素化蛋白及内质网应激相关基因的表达。结果:在缺氧复氧2 h、4 h、6 h这3个时间点,加入MG132组大鼠肺泡巨噬细胞绿色荧光及泛素化蛋白(Ubiquitin)表达明显降低(P0.05),而PCR及Western blot示内质网应激基因BIP(免疫球蛋白结合蛋白)、XBP-1(X-盒结合蛋白)和CHOP(C/EBP同源蛋白)平均扩增量及蛋白表达量明显增加(P0.05);加入阿霉素组大鼠肺泡巨噬细胞在缺氧复氧2 h、4h、6 h表现出相反的实验结果,绿色荧光及Ubiquitin蛋白相对表达均明显增加(P0.05),而PCR及Western blot示内质网应激基因BIP、XBP-1和CHOP平均扩增量及蛋白表达量明显增加(P0.05)。结论:本实验结果表明活细胞泛素-蛋白酶体活性程度与内质网应激存在紧密联系,外源性增强泛素蛋白酶体活性会抑制内质网应激,外源性减弱泛素蛋白酶体活性会增强内质网应激。  相似文献   

9.
An efficient method for the synthesis of 5'-O-monomethoxytrityl-2',3'-dideoxy-2'-fluoro-3'-thioarabinothymidine [(5'MMT)araF-T(3'SH), (5)] and its 3'-phosphoramidite derivative (6) suitable for automated incorporation into oligonucleotides, is demonstrated. A key step in the synthesis involves reaction of 5'-O-MMT-2,3'-O-anhydrothymidine (4) (Eleuteri, A.; Reese, C.B.; Song, Q. J. Chem. Soc. Perkin Trans. 1 1996, 2237 pp.) with sodium thioacetate to give (5'-MMT)araF-T(3'SAc) (5) (Elzagheid, M.I.; Mattila, K.; Oivanen, M.; Jones, B.C.N.M.; Cosstick, L?nnberg, H. Eur. J. Org. Chem. 2000, 1987-1991). This nucleoside was then converted to its corresponding phosphoramidite derivative, 6, as described previously ((a) Sun, S.; Yoshida, A.; Piccirilli, J.A. RNA, 1997, 3, 1352-1363; (b) Matulic-Adamic, J.; Beigelman, L. Helvetica Chemica Acta 1999, 82, 2141-2150: (c) Fettes, K.J.; O'Neil, I.; Roberts, S.M.; Cosstick, R. Nucleosides, Nucleotides and Nucl. Acids 2001, 20, 1351-1354).  相似文献   

10.
Interesting and very promising antisense properties of 2'-deoxy-2'-fluoroarabinonucleic acids ((a) Wilds, C.J.; Damha, M.J. 2'-Deoxy-2'-fluoroarabinonucleosides and oligonucleotides (2'F-ANA): synthesis and physicochemical studies. Nucl. Acids Res. 2000, 28, 3625-3635; (b) Viazovkina, E.; Mangos, M.; Elzagheid, M.I.; Damha, M.J. Current Protocols in Nucleic Acid Chemistry 2002, 4.15.1-4.15.21) (2'F-ANA) has encouraged our research group to optimize the synthetic procedures for 2'-deoxy-2'-fluoro-beta-D-arabinonucleosides (araF-N). The synthesis of araF-U, araF-T, araF-A and araF-C is straightforward, (Tann, C.H.; Brodfuehrer, P.R.; Brundidge, S.P.; Sapino, C., Jr. Howell H.G. Fluorocarbohydrates in synthesis. An efficient synthesis of 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodouracil (beta-FIAU) and 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)thymine (beta-FMAU). J. Org. Chem. 1985, 50, 3644-3647; Howell, H.G.; Brodfuehrer, P.R.; Brundidge, S.P.; Benigni, D.A.; Sapino, C., Jr. Antiviral nucleosides. A stereospecific, total synthesis of 2'-fluoro-2'-deoxy-beta-D-arabinofuranosyl nucleosides. J. Org. Chem. 1988, 53, 85-88; Maruyama, T.; Takamatsu, S.; Kozai, S.; Satoh, Y.; Izana, K. Synthesis of 9-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)adenine bearing a selectively removable protecting group. Chem. Pharm. Bull. 1999, 47, 966-970) however, the synthesis of the guanine analogue is more complicated and affords poor to moderate yields of araF-G (4) ((a) Elzagheid, M.I.; Viazovkina, E.; Masad, M.J. Synthesis of protected 2'-deoxy-2'-fluoro-beta-D-arabinonucleosides. Synthesis of 2'-fluoroarabino nucleoside phosphoramidites and their use in the synthesis of 2'F-ANA. Current Protocols in Nucleic Acid Chemistry 2002, 1.7.1-1.7.19; (b) Tennila, T.; Azhayeva, E.; Vepsalainen, J.; Laatikainen, R.; Azhayev, A.; Mikhailopulo, I. Oligonucleotides containing 9-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-adenine and -guanine: synthesis, hybridization and antisense properties. Nucleosides, Nucleotides and Nucl. Acids 2000, 19, 1861-1884). Here we describe an efficient synthesis of araF-G (4) that involves coupling of 2-deoxy-2-fluoro-3,5-di-O-benzoyl-alpha-D-arabinofuranosyl bromide (1) with 2-chlorohypoxanthine (2) to afford 2-chloro-beta-araF-I (3) in 52% yield. Nucleoside (3) was transformed into araF-G (4) by treatment with methanolic ammonia (150 degrees C, 6 h) in 67% yield.  相似文献   

11.
Following the discovery of JTK-109 (1) as a potent inhibitor of hepatitis C virus NS5B RNA-dependent RNA polymerase, [(a) Hirashima, S.; Suzuki, T.; Ishida, T.; Noji, S.; Yata, S.; Ando, I.; Komatsu, M.; Ikeda, S.; Hashimoto, H. J. Med. Chem.2006, 49, 4721. (b) Hashimoto, H.; Mizutani, K.; Yoshida, A. Int. Patent Appl. WO 01/47883, 2001.] further studies toward the improvement of the cellular potency have been performed. A greater than 40-fold improvement was achieved through replacing the biphenyl moiety with a 2-morpholinophenyl group and the benzimidazole ring with the tetracyclic scaffold to afford compound 7 with an excellent replicon potency (EC(50)=7.6 nM).  相似文献   

12.
Recently, a series of potent and selective neuronal nitric oxide synthase inhibitors containing two basic nitrogen atoms was reported (Ji, H.; Stanton, B. Z.; Igarashi, J.; Li, H.; Martásek, P.; Roman, L. J.; Poulos, T. L.; Silverman, R. B. J. Am. Chem. Soc. 2008, 130, 3900–3914). In an effort to improve their bioavailability, three compounds (2ac) were designed with electron-withdrawing groups near one of the basic nitrogen atoms to lower its pKa. Inhibition studies with these compounds showed that two of them not only retained most of the potency and selectivity of the best analogue of the earlier series, but also showed improved membrane permeability based on data from a cell-based assay.  相似文献   

13.
Calcofluor White is a fluorescent probe that interacts with polysaccharides and is commonly used in clinical studies. Interaction between Calcofluor White and carbohydrate residues of alpha1-acid glycoprotein (orosomucoid) was previously studied at low and high concentrations of Calcofluor compared to that of the protein. alpha1-Acid glycoprotein contains 40% carbohydrate by weight and has up to 16 sialic acid residues. At equimolar concentrations of Calcofluor and alpha1-acid glycoprotein, the fluorophore displays free motions [Albani, J. R.; Sillen, A.; Coddeville, B.; Plancke, Y. D.; Engelborghs, Y. Carbohydr. Res. 1999, 322, 87-94], while at high concentration of Calcofluor, its surrounding microenvironment is rigid, inducing the rigidity of the fluorophore itself [Albani, J. R.; Sillen, A.; Plancke, Y. D.; Coddeville, B.; Engelborghs, Y. Carbohydr. Res. 2000, 327, 333-340]. In the present work, red-edge excitation spectra and steady-state anisotropy studies performed on Trp residues in the presence of Calcofluor, showed that the apparent dynamics of Trp residues are not modified. However, deconvoluting the emission spectra with two different methods into different components, reveals that the structure of the protein matrix has been disrupted in the presence of high Calcofluor concentrations.  相似文献   

14.
Urokinase-type plasminogen activator (uPA) and its receptor (uPAR) are instrumental in cellular activities during inflammation, angiogenesis and tumor metastasis. Recent studies suggest that uPA might exert its function on cell proliferation and migration in a uPAR-independent manner or through an adaptor to the uPA-uPAR system. By applying phage display technology, we have identified a putative uPA-binding consensus sequence BXXSSXXB (where B represents a basic amino acid and X represents any amino acid), which has no apparent sequence correlation to uPAR. This uPA-binding motif apparently recognizes the kringle domain of the protease and has an agonistic effect on uPA binding to immobilized uPAR, thereby possibly serving as part of an adaptor component for uPAR signaling. As a result of protein database searches, this motif was found in the extracellular domain of several cell surface proteins, some of which were proposed to be associated with the uPA-uPAR system. Among these, gp130, a common signal transducer for cytokines, was identified as a uPA-binding protein. The specificity of this interaction was demonstrated by inhibition of uPA binding to immobilized gp130 with soluble gp130. Furthermore, the binding could be partially inhibited by a uPA-binding consensus sequence-containing fusion protein in a dose-dependent manner, with an IC50 of approximately 1 microM, indicating that the uPA-binding motif is apparently involved in the uPA-gp130 interaction. The association of gp130 with uPA may link the uPA-uPAR system to various signal transduction pathways.  相似文献   

15.
We have recently reported that tyrosine kinase, p56(lck) regulates cell motility and nuclear factor kappaB-mediated secretion of urokinase-type plasminogen activator (uPA) through tyrosine phosphorylation of IkappaBalpha following hypoxia/reoxygenation (Mahabeleshwar, G. H., and Kundu, G. C. (2003) J. Biol. Chem. 278, 52598-52612). However, the role of hypoxia/reoxygenation (H/R) on ERK1/2-mediated uPA secretion and cell motility and the involvement of p56(lck) and EGF receptor in these processes in breast cancer cells is not well defined. We provide here evidence that H/R induces Lck kinase activity and Lck-dependent tyrosine phosphorylation of EGF receptor in highly invasive (MDA-MB-231) and low invasive (MCF-7) breast cancer cells. H/R also stimulates MEK-1 and ERK1/2 phosphorylations, and H/R-induced phosphorylations were suppressed by the dominant negative form of Lck (DN Lck, K273R) as well as pharmacological inhibitors of EGF receptor and Lck indicating that EGF receptors and Lck are involved in these processes. Transfection of these cells with wild type Lck or Lck F505 (Y505F) but not with Lck F394 (Y394F) induced phosphorylations of EGF receptor followed by MEK-1 and ERK1/2, suggesting that Lck is upstream of EGF receptor and Tyr-394 of Lck is crucial for these processes. H/R also induced uPA secretion and cell motility in these cells. DN Lck and inhibitors of Lck, EGF receptor, and MEK-1 suppressed H/R-induced uPA secretion and cell motility. To our knowledge, this is the first report that p56(lck) in presence of H/R regulates MEK-1-dependent ERK1/2 phosphorylation and uPA secretion through tyrosine phosphorylation of EGF receptor, and it further demonstrates that all of these signaling molecules ultimately control the motility of breast cancer cells.  相似文献   

16.
Urokinase-type (uPA) plasminogen activator is regulated by serine protease inhibitors (serpins), especially plasminogen activator inhibitor-1 (PAI-1). In many cancers, uPA and PAI-1 contribute to the invasive phenotype. We examined the in vitro migration and invasive capabilities of breast, ovarian, endometrial, and cervical cancer cell lines compared to their plasminogen activator system profiles. We then overexpressed active wild-type PAI-1 and an inactive "substrate" P14 form of PAI-1 (T333R) using stable transfection and adenoviral gene delivery. We also upregulated endogenous uPA and PAI-1 in these cells by treatment with transforming growth factor-beta. Some breast and ovarian cancer cell lines with natural expression of uPA, PAI-1, and urokinase receptor showed substantial migration and invasion compared to other cell lines that lack expression of these proteins. However, overexpression of active wild-type PAI-1, but not P14-PAI-1 (T333R), in these cell lines showed reduced migration and invasion. Since vitronectin binding by both forms of PAI-1 is equivalent, these results imply that PAI-1-vitronectin interactions are less critical in altering migration and invasion. Our results show that the in vitro migratory and invasive phenotype in these breast and ovarian cancer cell lines is reduced by active PAI-1 due to its ability to inhibit plasminogen activation.  相似文献   

17.
The effects of natural and synthetic eicosanoids on the diameter of rat interlobular arteries studied in vitro were compared to that of the potent, endogenous vasoconstrictor 20-HETE. Vasoconstrictor activity was optimum for chain lengths of 20-22 carbons with at least one olefin or epoxide between located between C(13)-C(15) and an oxygen substituent at C(20)-C(22). The presence of delta (Zou et al. Am. J. Physiol. 1996, 270, R228; Gebremedhin, D. et al. Am. J. Physiol. 1998, 507, 771)-, delta (Carroll et al. Am. J. Physiol. 1996, 271, R863; Vazquez et al. Life Sci. 1995, 56, 1455)-, or delta (Imig et al. Hypertension 2000, 35, 307; Lopez et al. Amer. J. Physiol. 2001, 281, F420)-olefins had no influence on the vasoconstrictor response whereas the introduction of a C(7)-thiomethylene enhanced potency. A sulfonamide or alcohol, but not a lactone, could replace the C(1)-carboxylate. These data were used to construct a putative binding domain map of the 20-HETE receptor consisting of: (i) a comparatively open, hydrophilic binding site accommodating the C(1)-functionality; (ii) a hydrophobic trough spanning the olefins; (iii) a shallow pocket containing a critical pi-pi binding site in the vicinity of the pi (Ito et al. Am. J. Physiol. 1998, 274, F395; Quigley, R.; Baum, M.; Reddy, K. M.; Griener, J. C.; Falck, J. R. Am. J. Physiol. 2000, 278, F949)-olefin; and (iv) an oxyphilic binding site proximate to the omega-terminus.  相似文献   

18.
The relative non-toxicity of the diuretic amiloride, coupled with its selective inhibition of the protease urokinase plasminogen activator (uPA), makes this compound class attractive for structure-activity studies. Herein we substituted the C(2)-acylguanidine of C(5)-glycyl-amiloride with amidine and amidoxime groups. The data show the importance of maintaining C(5)-hydrophobicity. The C(5)-benzylglycine analogs containing either C(2)-acylguanidine or amidine inhibited uPA with an IC(50) ranging from 3 to 7 μM and were cytotoxic to human U87 malignant glioma cells.  相似文献   

19.
T uck , G. S.; H einzel , H.: Die Meeresvögel der Welt. Ein Taschenbuch für Ornithologen und Naturf reunde. Aus dem Englischen übers. u. bearb. von E lisabeth und Dr. H. G oethe
K nussmann , R.: Vergleichende Biologie des Menschen
K aestner , A. (Begründer): Lehrbuch der speziellen Zoologie. Band I: Wirbellose Tiere. Herausgegeben von H ans -E ckhard G runer
H eberer , G.: Allgemeine Abstammungslehre. 2., neu bearb. und erweit. Aufl. von B. Z epernick
M oore , W. J.: The Mammalian Skull. Biological Structure and Function 8
R andall , D. J.; B urggren , W. W.; F arrell , A. P.; H aswell , M. S.: The evolution of air breathing in vertebrates
S auer , H. W.: Entwicklungsbiologie. Ansätze zu einer Synthese. Mit einem Geleitwort vonF. S eidel . Hochschultext
H ardisty , M. W.: Biology of the Cyclostomes. (Biologie der Cyclostomen). London: Chapman and Hall 1979. XIV, 428 S., zahlreiche Abb., graph
W eick , F.: Die Greifvögel der Welt. Ein farbiger Führer zur Bestimmung der Ordnung Fakoniformes. Unter Mitarbeit von L. H. B rown , Karen, Kenia. Hamburg und Berlin
A pfelbach , R.; D öhl , J.: Verhaltensforschung. 3., neubearb. u. erw. Aufl
H ennig , W illi : Phylogenetische Systematik. Hrsg. Prof. Dr. W olfgang H ennig
K ämpfe , L.; K ittel , R.; K lapperstück , J.: Leitfaden der Anatomie der Wirbeltiere. 4.,überarb  相似文献   

20.
Book reviewed in this article:
reviews type of article–
M ason , J. L. (ed.): Evolution of domesticated animals . London, New York: Longman 1984.
G riffiths , G. C. D. (ed.): Flies of the Nearctic Region . Vol. VIII: Cyclorrhapha II (Schizophora: Calyptratae), Part 2 Anthomyiidae, Number 1 by G. C. D. G riffiths . Stuttgart: E. Schweitzerbart'sche Verlagsbuchhandlung 1982.
S impson , G. G.: Penguins . Past and Present, Here and There. New Haven and London: Yale University Press 1983.
G ans , E.; P ouch , F. H. (eds.): Biology of the Reptilia . Vol. 12. New York – London: Academic Press 1982. 564 S. DM 353,–. G ans , E. (ed.):
M atsuno , K.; D ose , K.; H arada , K.; R ohlfing , D. L. (eds.): Molecular Evolution and Protobiology . New York, London
F elsenstein , J. (ed.): Numerical Taxonomy . Nato AS1 Series. Series G Ecological Sciencesxs
S meets , W. J. A. J.; N ieuwenhuys , R.; R oberts , B. L.: The Central Nervous System of Cartilaginous Fishes . Structure and Functional Correlations. Berlin, Heidelberg, New York: Springer 1983
H echt , M. K.; W allace , B.; P range , G. T. (eds.): Evolutionary Biology . Vol. 18. New York and London  相似文献   

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