1,720,971 research outputs found
Structural And Chemical Basis For Anticancer Activity Of A Series Of β-tubulin Ligands: Molecular Modeling And 3d Qsar Studies
Get PDFAn important approach to cancer therapy is the design of small molecule modulators that interfere with microtubule dynamics through their specific binding to the β-subunit of tubulin. In the present work, comparative molecular field analysis (CoMFA) studies were conducted on a series of discodermolide analogs with antimitotic properties. Significant correlation coefficients were obtained (CoMFA(i), q2 = 0.68, r2 = 0.94; CoMFA(ii), q2 = 0.63, r2 = 0.91), indicating the good internal and external consistency of the models generated using two independent structural alignment strategies. The models were externally validated employing a test set, and the predicted values were in good agreement with the experimental results. The final QSAR models and the 3D contour maps provided important insights into the chemical and structural basis involved in the molecular recognition process of this family of discodermolide analogs, and should be useful for the design of new specific β-tubulin modulators with potent anticancer activity. ©2009 Sociedade Brasileira de Química.204693703Wittmann, T., Hyman, A., Desai, A., (2001) Nat. Cell. Biol., 3, pp. E28Jordan, M.A., Wilson, L., (2004) Nat. Ver. Cancer, 4, p. 253Hadfield, J.A., Ducki, S., Hirst, N., McGown, A.T., (2003) Prog. Cell Cycle Res., 5, p. 309Pellegrini, F., Budman, D.R., (2005) Cancer Invest, 23, p. 264Islam, M.N., Iskander, M.N., (2004) Mini Rev. Med. Chem., 4, p. 1077Snyder, J.P., (2007) Nat. Chem. Biol., 3, p. 81Schiff, P.B., Fant, J., Horwitz, S.B., (1979) Nature, 277, p. 665Rowinsky, E.K., (1997) Annu. Rev. Med., 48, p. 353Jordan, M.A., Toso, R.J., Thrower, D., Wilson, L., (1993) Proc. Natl. Acad. Sci. U. S. 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Chem., 15, p. 37Andricopulo, A.D., Montanari, C.A., (2005) Mini-Rev. Med. Chem., 5, p. 585Salum, L.B., Polikarpov, I., Andricopulo, A.D., (2007) J. Mol. Graphics Modell., 26, p. 43Castilho, M.S., Postigo, M.P., de Paula, C.B., Montanari, C.A., Oliva, G., Andricopulo, A.D., (2006) Bioorg. Med. Chem., 14, p. 516Andrade, C.H., Salum, L.B., Pasqualoto, K.F.M., Ferreira, E.I., Andricopulo, A.D., (2008) Lett. Drug Des. Discov., 5, p. 377Guido, R.V.C., Oliva, G., Montanari, C.A., Andricopulo, A.D., (2008) J. Chem. Inf. Model., 48, p. 918Salum, L.B., Polikarpov, I., Andricopulo, A.D., (2009) J. Chem. Inf. Model., 48, p. 2243Honório, K.M., Garratt, R.C., Polikarpov, I., Andricopulo, A.D., (2007) J. Mol. Graph. Modell., 25, p. 921Salum, L.B., Dias, L.C., Andricopulo, A.D., (2009) QSAR Comb. Sci., 28, p. 325Castilho, M.S., Guido, R.V.C., Andricopulo, A.D., (2007) Lett. Drug Des. Discov., 4, p. 106Manetti, F., Maccari, L., Corelli, F., Botta, M., (2005) J. Mol. 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Fragment-based Qsar And Molecular Modeling Studies On A Series Of Discodermolide Analogs As Microtubule-stabilizing Anticancer Agents
No full textInhibition of microtubule function is an attractive rational approach to anticancer therapy. Although taxanes are the most prominent among the microtubule-stabilizers, their clinical toxicity, poor pharmacokinetic properties, and resistance have stimulated the search for new antitumor agents having the same mechanism of action. Discodermolide is an example of nontaxane natural product that has the same mechanism of action, demonstrating superior antitumor efficacy and therapeutic index. The extraordinary chemical and biological properties have qualified discodermolide as a lead structure for the design of novel anticancer agents with optimized therapeutic properties. In the present work, we have employed a specialized fragment-based method to develop robust quantitative structure - activity relationship models for a series of synthetic discodermolide analogs. The generated molecular recognition patterns were combined with three-dimensional molecular modeling studies as a fundamental step on the path to understanding the molecular basis of drug - receptor interactions within this important series of potent antitumoral agents. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.283325337Pellegrini, F., Budman, D.R., (2005) Cancer Invest, 23, pp. 264-273Jordan, A., Hadfield, J.A., Lawrence, N.J., McGown, A.T., (1998) Med. Res. Rev, 18, pp. 259-296Wittmann, T., Hyman, A., Desai, A., (2001) Nat. Cell. Biol, 3, pp. E28-E34Rowinsky, E.K., (1997) Annu. Rev. Med, 48, pp. 353-374Hadfield, J.A., Ducki, S., Hirst, N., McGown, A.T., (2003) Prog. Cell. Cycle Res, 5, pp. 309-325Islam, M.N., Iskander, M.N., (2004) Mini Rev. Med. Chem, 4, pp. 1077-10104Jordan, M.A., Wilson, L., (2004) Nat. Rev. Cancer, 4, pp. 253-265Minguez, J.M., Giuliano, K.A., Balachandran, R., Madiraju, C., Curran, D.P., Day, B.W., (2002) Mol. 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Chem, 5, pp. 585-593Burlingame, M.A., Shaw, S.J., Sundermann, K.F., Zhang, D., Petryka, J., Mendoza, E., Liu, F., Smith III, A.B., (2004) Bioorg. Med. Chem. Lett, 14, pp. 2335-2338Shaw, S.J., Sundermann, K.F., Burlingame, M.A., Myles, D.C., Freeze, B.S., Xian, M., Brouard, I., Smith III, A.B., (2005) J. Am. Chem. Soc, 127, pp. 6532-6533Smith III, A.B., Freeze, B.S., Lamarche, M.J., Hirose, T., Brouard, I., Rucker, P.V., Xian, M., Myles, D.C., (2005) Org. Lett, 7, pp. 311-314Smith III, A.B., Freeze, B.S., Lamarche, M.J., Hirose, T., Brouard, I., Xian, M., Sundermann, K.F., Myles, D.C., (2005) Org. Lett, 7, pp. 315-318Smith III, A.B., Xian, M., (2005) Org. Lett, 7, pp. 5229-5232HQSARTM Manual Release in SYBYL 8.0, Tripos Inc., St. Louis, MO 2008Salum, L.B., Polikarpov, I., Andricopulo, A.D., (2007) J. Mol. Graph. Model, 25, pp. 434-442Castilho, M.S., Guido, R.V.C., Andricopulo, A.D., (2007) Bioorg. Med. 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Lett, 15, pp. 3119-3125Kar, S., Florence, G.J., Paterson, I., Amos, L.A., (2003) FEBS Lett, 539, pp. 34-36Andricopulo, A.D., Yunes, R.A., (2001) Chem. Pharm. Bull, 49, pp. 10-1
Quantitative Structure-activity Studies On A Series Of Igrastatin Analogs As Inhibitors Of Cancer Cell Metastasis
No full textMigrastatin, a macrolide natural product, and its structurally related analogs are potent inhibitors of cancer cell metastasis, invasion and migration. In the present work, a specialized fragment-based method was employed to develop QSAR models for a series of migrastatin and isomigrastatin analogs. Significant correlation coefficients were obtained (best model, q 2 = 0.76 and r 2 = 0.91) indicating that the QSAR models possess high internal consistency. The best model was then used to predict the potency of an external test set, and the predicted values were in good agreement with the experimental results (R 2 pred = 0.85). The final model and the corresponding contribution maps, combined with molecular modeling studies, provided important insights into the key structural features for the anticancer activity of this family of synthetic compounds based on natural products. © 2011 Bentham Science Publishers Ltd.73155164Bode, A.M., Dong, Z., Cancer prevention research-then and now (2009) Nat. Rev. Cancer, 9, pp. 508-516Hedley, B.D., Winquist, E., Chambers, A.F., Therapeutic targets for antimetastatic therapy (2004) Expert Opinion on Therapeutic Targets, 8 (6), pp. 527-536. , DOI 10.1517/14728222.8.6.527Nakae, K., Yoshimoto, Y., Sawa, T., Homma, Y., Hamada, M., Takeuchi, T., Imoto, M., Migrastatin a new inhibitor of tumor cell migration from Streptomyces sp. MK929-43F1 taxonomy, fermentation, isolation and biological activities (2000) J. Antibiot., 53, pp. 1130-1136Woo, E.J., Starks, C.M., Carney, J.R., Arslanian, R., Cadapan, L., Zavala, S., Licari, P., Migrastatin and a new compound, isomigrastatin (2002) Streptomyces Platensis J. Antibiot., 55, pp. 141-146Ju, J., Rajski, S.R., Lim, S., Seo, J., Peters, M.R., Hoffmann, F.M., Lactimidomycin, S.B., Iso-migrastatin and related glutarimidecontaining 12-membered macrolides are extremely potent inhibitors of cell migration (2009) J. Am. Chem. Soc., 131, pp. 1370-1371Gaul, C., Njardarson, J.T., Shan, D., Dorn, D.C., Wu, K.-D., Tong, W.P., Huang, X.-Y., Danishefsky, S.J., The migrastatin family: Discovery of potent cell migration inhibitors by chemical synthesis (2004) Journal of the American Chemical Society, 126 (36), pp. 11326-11337. , DOI 10.1021/ja048779qNjardarson, J.T., Gaul, C., Shan, D., Huang, X., Danishefsky, S.J., Discovery of potent cell migration inhibitors through total syn (2004) J. Am. Chem. Soc., 126, pp. 1038-1040. , thesis: lessons from structure-activity studies of (+)-migrastatinShan, D., Chen, L., Njardarson, J.T., Gaul, C., Ma, X., Danishefsky, S.J., Huang, X.-Y., Synthetic analogues of migrastatin that inhibit mammary tumor metastasis in mice (2005) Proceedings of the National Academy of Sciences of the United States of America, 102 (10), pp. 3772-3776. , DOI 10.1073/pnas.0500658102Dias, L.C., Finelli, F.G., Conegero, L.S., Krogh, R., Andricopulo, A.D., Synthesis of the macrolactone of migrastatin and analogs with potent cell migration inhibitory activity Eur. J. Org. 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Sci., 28, pp. 325-337Hashimoto, Y., Shimada, Y., Kawamura, J., Yamasaki, S., Imamura, M., The prognostic relevance of fascin expression in human gastric carcinoma (2004) Oncology, 67 (3-4), pp. 262-270. , DOI 10.1159/000081327Honorio, K.M., Garratt, R.C., Polikarpov, I., Andricopulo, A.D., 3D QSAR comparative molecular field analysis on nonsteroidal farnesoid X receptor activators (2007) Journal of Molecular Graphics and Modelling, 25 (6), pp. 921-927. , DOI 10.1016/j.jmgm.2006.09.003, PII S1093326306001215Guido, R.V.C., Castilho, M.S., Mota, S., Oliva, G., Andricopulo, A.D., Classical and hologram QSAR studies on a series of inhibitors of trypanosomatid glyceraldehyde-3-phosphate dehydrogenase (2008) QSAR Comb. 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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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