Hippocampal Insulin Signaling And Neuroprotection Mediated By Physical Exercise In Alzheimeŕs Disease

Epidemiological studies indicate continuous increases in the prevalence of Alzheimer's Disease (AD) in the next few decades. The key feature of this disease is hippocampal neurodegeneration. This structure has an important role in learning and memory. Intense research efforts have sought to elucidate neuroprotective mechanisms responsible for hippocampal integrity. Insulin signaling seems to be a very promising pathway for the prevention and treatment of AD. This hormone has been described as a powerful activator of neuronal survival. Recent research showed that reduced insulin sensitivity leads to low-grade inflammation, and both phenomena are closely related to AD genesis. Concomitantly, exercise has been shown to exert anti-inflammatory effects and to promote improvement in insulin signaling in the hippocampus, which supports neuronal survival and constitutes an interesting non-pharmacological alternative for the prevention and treatment of AD. This review examines recent advances in understanding the molecular mechanisms involved in hippocampal neuroprotection mediated by exercise.2

Extending The Kinetic Solution Of The Classic Michaelis-menten Model Of Enzyme Action

The principal aim of studies of enzyme-mediated reactions has been to provide comparative and quantitative information on enzyme-catalyzed reactions under distinct conditions. The classic Michaelis-Menten model (Biochem Zeit 49:333, 1913) for enzyme kinetic has been widely used to determine important parameters involved in enzyme catalysis, particularly the Michaelis-Menten constant (K M) and the maximum velocity of reaction (V max). Subsequently, a detailed treatment of the mechanisms of enzyme catalysis was undertaken by Briggs-Haldane (Biochem J 19:338, 1925). These authors proposed the steady-state treatment, since its applicability was constrained to this condition. The present work describes an extending solution of the Michaelis-Menten model without the need for such a steady-state restriction. We provide the first analysis of all of the individual reaction constants calculated analytically. Using this approach, it is possible to accurately predict the results under new experimental conditions and to characterize and optimize industrial processes in the fields of chemical and food engineering, pharmaceuticals and biotechnology. © 2011 Springer Science+Business Media, LLC.49919761995O'Sulivan, C., Tompson, S.W., (1890) J. Chem. Soc. Faraday Trans., 57, p. 834Cornish-Bowden, A., (2004) Fundamentals of Enzyme Kinetics, , London: Portland PressBrown, G.C., (1892) J. Chem. Soc. Faraday Trans., 61, p. 369Henri, V., (1902) CR. Hebd. Seanc. Acad. Sci., 135, p. 916Henri, V., (1903) Lois Générale De l'action De Diastase, , Paris: HermannMichaelis, L., Menten, M.L., (1913) Biochem. Zeit., 49, p. 333Briggs, G., Haldane, J., (1925) Biochem. J., 19, p. 338Gibson, Q.H., (1969) Method. Enzymol., 16, p. 187Ajila, C., Rao, U., (2009) J. Mol. Catal. B Enzym., 60, p. 36Leon, J.C., Alpeeva, I.S., Chubar, T.A., Galaev, I.Y., Csoregi, E., Sakharov, I.Y., (2002) Plant Sci., 163, p. 1011Carvalho, A.S.L., Melo, E.P.E., Ferreira, B.S., Neves-Petersen, M.T., Petersen, S.B., Aires-Barros, M.R., (2003) Arch. Biochem. Biophys., 415, p. 257Wang, L., Burhenne, K., Kristensen, B., Rasmussen, S., (2004) Gene, 343, p. 323Johri, S., Jamwal, U., Rasool, S., Kumar, A., Verma, V., Qazi, G.N., (2005) Plant Sci., 169, p. 1014Rosenthal, A., Ledward, D., Defaye, A., Gilmour, S., Trinca, L., (2002) Trends HP Biosci. Biotech., 19, p. 525Agostini, E., Hernandez-Ruiz, J., Arnão, M.B., Milrand, S.R., Tigier, H.A., Acosta, M., (2002) Biotechnol. Appl. Biochem., 35, p. 1Morales-Blancas, E., Chandia, V., Cisneros-Zevallos, L., (2002) J. Food Sci., 67, p. 146Antonini, E., Brunori, M., (1971) Hemoglobin and Myoblobin in Their Reactions with Ligands, , London: North Holland Publishing CompanyAibara, S., Yamashita, H., Mori, E., Kato, M., Morita, Y., (1982) J. Biochem., 92, p. 531Kreyszig, E., (2009) Matemática Superior Para Engenharia, , Rio de Janeiro: LTCSchmidell, W., Lima, U.A., Aquarone, E., Borzani, W., (2001) Industrial Biotechnology, , São Paulo: Ed. Edgar BlücherMonod, J., The growth of bacterial cultures (1949) Annu. Rev. Microbiol., 3, p. 371Fonseca, M., Teixeira, J.A., (2007) Reactores Biológicos, , Lisboa, Porto: LidelSilva, D., Branyik, T., Dragone, G., Vicente, A.A., Teixeira, J.A., Silva, J.B.A., (2008) Chem. Pap., 62, p. 34Carvalho, G.B.M., Silva, D.P., Bento, C.V., Vicente, A.A., Teixeira, J.A., Felipe, M.G., Silva, J.B.A., (2009) Appl. Biochem. Biotechnol., 155, p. 55Lineweaver, H., Burk, D., (1934) J. Am. Chem. Soc., 56, p. 65

Measurements of Medium Wave HD Radio Reception in a Dense Urban Region

Abstract This paper presents the results of measurements of medium wave received field strength, HD Radio audio quality and maximum coverage distances in a dense urban region. Analog AM and digital HD Radio signals broadcasting the same content were simultaneously transmitted in São Paulo, the largest city in Brazil. The received signal intensity and the reception quality were recorded along radial routes of up to 45 km from the transmitter under both mobile and static conditions, enabling the comparative assessment of the digital and analog system performances