**6. References**


<sup>\*</sup> Corresponding Author

[6] Mrué F. (2000). *Reparo de lesões parciais do esôfago cervical utilizando biomembrana de látex natural com polilisina*, Monografia do exame de qualificação, Faculdade de Medicina da Universidade de São Paulo, Ribeirão Preto, 33p.

184 Practical Applications in Biomedical Engineering

premises.

**5. Conclusion** 

gastro-intestinal anatomy.

Suélia de S. Rodrigues Fleury Rosa\*

*Engineering & Innovation Laboratory,* 

de São Paulo, Ribeirão Preto, 114p.

*University de Brasilia, Gama Campus, Setor Central, Gama-DF, Brazil* 

Medicine and Biology Magazine, 2010, Jan-Fev, p.24-30.

**Author details** 

**6. References** 

p. 518-523.

Corresponding Author

 \*

in the blood, and furthermore without altering the digestive tract –, through a minimally invasive procedure, is a fact that is appealing within the current context of society. But, in validation of the conclusions reached in the experiments that support this study, it was revealed that a desire such as this has not yet been achieved from the scientifically proven

The effects of mastication exert an influence on the mechanisms that trigger satiety. It implies nutritional re-education in individuals with obesity and also weight loss, as observed in previous studies. One can read in studies by many authors that new studies regarding procedures for treating obesity are necessary, particularly with the goal of improving the results and decreasing the costs and morbidity of obese patients. But, the basic, necessary characteristics for comprising a new treatment should be founded. On a minimally invasive procedure, without side effects, that would not interfere or modify

[1] Rutherford JJ.Biomedical engineering and the obesity epidemic.Engineering in

[2] Dib N, Elhajj I, Antoun S, Al-Hajj G. Gastrectomy Surgical Assistive Instrument for Accurate Remnant Stomach Volume. Proceedings of the IEEE International Conference on Robotics and Biomimetics Bangkok, Thailand, February 21 - 26, 2009,

[3] Partida, M.A.; Cardiel, E.; Rojano, M.E.; Urrutia, R.; Hernandez, P.R..Experimental Gastric Stimulator for Refractory Obesity Treatment.Electrical and Electronics Engineering, 2006 3rd International Conference on Veracruz, Sept. 6-8, 2006 p. 01-04. [4] Fishman E, Melanson D, Lamport R, Levine A, GI Dynamics, Inc., Lexington, MA. A Novel Endoscopic Delivery System for Placement of a Duodenal-Jejunal Implant for the Treatment of Obesity and Type 2 Diabetes. 30th Annual International IEEE EMBS Conference Vancouver, British Columbia, Canada, August 20-24, 2008 p. 2501-2503. [5] Mrué F. (1996). *Substituição do Esôfago Cervical por Prótese Biossintética de látex: estudo experimental em cães*, Dissertação de Mestrado, Faculdade de Medicina da Universidade

, Adson Ferreira da Rocha and José Conceição Carvalho

	- [22] Karason S., Karlsen K.L., Lundin S. et al. (1999). "A simplified method for separate measurements of lung and chest wall mechanics in ventilator-treated patients". In: ActaAnaesthesiolScand, 43, 308-315.

**Chapter 8** 

© 2012 Chernolovskaya et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2012 Chernolovskaya et al., licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

**Structure - Functions Relations in Small** 

Natalya S. Petrova, Marina A. Zenkova and Elena L. Chernolovskaya

RNA interference is an evolutionary conserved mechanism of specific gene silencing induced by double stranded RNA homologous to the target mRNA. Small interfering RNAs (siRNAs) are widely used for the control of gene expression in molecular biology and experimental pharmacology. Currently, siRNAs are successfully used for the validation of potent drug targets for anti-cancer therapy. However, application of siRNAs as therapeutics is limited by their sensitivity to ribonucleases, poor cellular uptake and rapid size-mediated renal clearance. These challenges must be overcome to develop a successful siRNA-based drug. Many of these limitations could be resolved with the use of chemical modifications

This review examines recent data regarding principals of the design of siRNA for the silencing of therapeutically relevant genes. A particular focus will be made on chemical modifications and their impact on siRNA potency, nuclease resistance and duration of the silencing effect. The types of chemical modifications, their location in siRNA structure influence siRNA properties in different modes: modulation of the interaction with RNAi proteins, the thermal stability and thermoasymmetry of the duplex and the sensitivity to the

Special attention will be paid to the design of siRNA for the silencing of thermodynamically unfavorable targets: mutant and chimerical genes. In this case the utilization of computer algorithms for the selection of active siRNA cannot be applied. Modification of siRNA structure aimed at the correction of the thermoasymmetry by incorporation of nucleotide substitutions, blocking incorporation of the sense strand in the RISC complex by truncation of one overhang or inactivation of the sense strand can be successfully used. Mismatches in the central part of the duplex can facilitate the cleavage and dissociation of the "passenger" (sense) strand, whereas selective chemical modification protects the non-perfect duplex

**Interfering RNAs** 

http://dx.doi.org/10.5772/53945

improving the siRNA properties.

degradation by ribonucleases.

from accelerated degradation.

**1. Introduction** 

Additional information is available at the end of the chapter

[23] Kwan K.Y., Kaler K.V.I.S., Mintchev M. P. (2002). "High-pressure balloon catheter for real-time pressure monitoring in the esophagus". In: Institute of Electrical and Electronic Engineers Sensors Journal, 1211-1214.
