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Search Results: 1 - 10 of 842587 matches for " M. A. De la Garza-Ramos "
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Detection of Helicobacter pylori in dental plaque of mexican children by real-time PCR  [PDF]
J. A. Valdez-Gonzalez, P. C. Mares-Moreno, M. J. Kowolik, J. Vargas-Villlarreal, F. Gonzalez-Salazar, M. A. De la Garza-Ramos
Health (Health) , 2014, DOI: 10.4236/health.2014.64034
Abstract:

Dental plaque in adult patients is well identified as a reservoir for Helicobacter pylori. This question still remains unclear in children. The aim of this study is to identify the presence of this bacterium in dental plaque of Mexican pediatric patients, using Real Time Polymerase Chain Reaction (qPCR). Forty patients from 2 to 11 years without dyspeptic symptoms were enrolled. Samples were collected from the subgingival space of the lingual side of the lower molars and cultured in selective medium. Therefore, qPCR analysis was conducted. According to the results obtained in this study, it was found that 35% of the pediatric population who participated tested qPCR positive for the presence of H. pylori in dental plaque samples. No significant associations were detected among isolation rate by gender or age. We found that dental plaque may be a reservoir for H. pylori. However, more research is needed to establish the way of the infection of pediatric population.

Zerovalent bismuth nanoparticles inhibit Streptococcus mutans growth and formation of biofilm
Hernandez-Delgadillo R, Velasco-Arias D, Diaz D, Arevalo-Ni o K, Garza-Enriquez M, De la Garza-Ramos MA, Cabral-Romero C
International Journal of Nanomedicine , 2012, DOI: http://dx.doi.org/10.2147/IJN.S29854
Abstract: ovalent bismuth nanoparticles inhibit Streptococcus mutans growth and formation of biofilm Rapid Communication (3504) Total Article Views Authors: Hernandez-Delgadillo R, Velasco-Arias D, Diaz D, Arevalo-Ni o K, Garza-Enriquez M, De la Garza-Ramos MA, Cabral-Romero C Published Date April 2012 Volume 2012:7 Pages 2109 - 2113 DOI: http://dx.doi.org/10.2147/IJN.S29854 Received: 11 January 2012 Accepted: 28 February 2012 Published: 24 April 2012 Rene Hernandez-Delgadillo1, Donaji Velasco-Arias2, David Diaz2, Katiushka Arevalo-Ni o1, Marianela Garza-Enriquez1, Myriam A De la Garza-Ramos1, Claudio Cabral-Romero1 1Instituto de Biotecnologia, Centro de Investigacion y Desarrollo en Ciencias de la Salud, CIDICS, Facultad de Odontologia, Universidad Autonoma de Nuevo Leon, UANL, Monterrey, Nuevo Leon, 2Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Distrito Federal, Mexico Background and methods: Despite continuous efforts, the increasing prevalence of resistance among pathogenic bacteria to common antibiotics has become one of the most significant concerns in modern medicine. Nanostructured materials are used in many fields, including biological sciences and medicine. While some bismuth derivatives has been used in medicine to treat vomiting, nausea, diarrhea, and stomach pain, the biocidal activity of zerovalent bismuth nanoparticles has not yet been studied. The objective of this investigation was to analyze the antimicrobial activity of bismuth nanoparticles against oral bacteria and their antibiofilm capabilities. Results: Our results showed that stable colloidal bismuth nanoparticles had 69% antimicrobial activity against Streptococcus mutans growth and achieved complete inhibition of biofilm formation. These results are similar to those obtained with chlorhexidine, the most commonly used oral antiseptic agent. The minimal inhibitory concentration of bismuth nanoparticles that interfered with S. mutans growth was 0.5 mM. Conclusion: These results suggest that zerovalent bismuth nanoparticles could be an interesting antimicrobial agent to be incorporated into an oral antiseptic preparation.
Potassium and Ionic Strength Effects on the Conformational and Thermal Stability of Two Aldehyde Dehydrogenases Reveal Structural and Functional Roles of K+-Binding Sites
Georgina Garza-Ramos, Carlos Mújica-Jiménez, Rosario A. Mu?oz-Clares
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0054899
Abstract: Many aldehyde dehydrogenases (ALDHs) have potential potassium-binding sites of as yet unknown structural or functional roles. To explore possible K+-specific effects, we performed comparative structural studies on the tetrameric betaine aldehyde dehydrogenase from Pseudomonas aeruginosa (PaBADH) and on the dimeric BADH from spinach (SoBADH), whose activities are K+-dependent and K+-independent, respectively, although both enzymes contain potassium-binding sites. Size exclusion chromatography, dynamic light scattering, far- and near-UV circular dichroism, and extrinsic fluorescence results indicated that in the absence of K+ ions and at very low ionic strength, PaBADH remained tetrameric but its tertiary structure was significantly altered, accounting for its inactivation, whereas SoBADH formed tetramers that maintained the native tertiary structure. The recovery of PaBADH native tertiary-structure was hyperbolically dependent on KCl concentration, indicating potassium-specific structuring effects probably arising from binding to a central-cavity site present in PaBADH but not in SoBADH. K+ ions stabilized the native structure of both enzymes against thermal denaturation more than did tetraethylammonium (TEA+) ions. This indicated specific effects of potassium on both enzymes, particularly on PaBADH whose apparent Tm values showed hyperbolical dependence on potassium concentration, similar to that observed with the tertiary structure changes. Interestingly, we also found that thermal denaturation of both enzymes performed in low ionic-strength buffers led to formation of heat-resistant, inactive soluble aggregates that retain 80% secondary structure, have increased β-sheet content and bind thioflavin T. These structured aggregates underwent further thermal-induced aggregation and precipitation when the concentrations of KCl or TEACl were raised. Given that PaBADH and SoBADH belong to different ALDH families and differ not only in amino acid composition but also in association state and surface electrostatic potential, the formation of this kind of β-sheet pre-fibrillar aggregates, not described before for any ALDH enzyme, appear to be a property of the ALDH fold.
Semblanza del profesor Juan Bautista de Oyarzabal Orueta
E. Pi?a Garza,M. de la P. Ramos Lara,C. L. Velasco Flores
Revista mexicana de física , 2006,
Abstract: En este trabajo hacemos una semblanza del profesor de física y marino, Juan Bautista de Oyarzabal Orueta (1913-1977). Damos algunos datos familiares y se expone su labor conocida como marino espa ol (1931-1939), como estudiante en México, y como investigador científico y profesor mexicano (naturalizado mexicano en 1941), principalmente en la Universidad Nacional Autónoma de México (1944-1977) y en el Instituto Politécnico Nacional (1945-1962).
Moonlighting Peptides with Emerging Function
Jonathan G. Rodríguez Plaza, Amanda Villalón Rojas, Sur Herrera, Georgina Garza-Ramos, Alfredo Torres Larios, Carlos Amero, Gabriela Zarraga Granados, Manuel Gutiérrez Aguilar, María Teresa Lara Ortiz, Carlos Polanco Gonzalez, Salvador Uribe Carvajal, Roberto Coria, Antonio Pe?a Díaz, Dale E. Bredesen, Susana Castro-Obregon, Gabriel del Rio
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0040125
Abstract: Hunter-killer peptides combine two activities in a single polypeptide that work in an independent fashion like many other multi-functional, multi-domain proteins. We hypothesize that emergent functions may result from the combination of two or more activities in a single protein domain and that could be a mechanism selected in nature to form moonlighting proteins. We designed moonlighting peptides using the two mechanisms proposed to be involved in the evolution of such molecules (i.e., to mutate non-functional residues and the use of natively unfolded peptides). We observed that our moonlighting peptides exhibited two activities that together rendered a new function that induces cell death in yeast. Thus, we propose that moonlighting in proteins promotes emergent properties providing a further level of complexity in living organisms so far unappreciated.
SHV-type extended-spectrum beta-lactamase (ESBL) are encoded in related plasmids from enterobacteria clinical isolates from Mexico
Garza-Ramos,Ulises; Martínez-Romero,Esperanza; Silva-Sánchez,Jesús;
Salud Pública de México , 2007, DOI: 10.1590/S0036-36342007000600008
Abstract: objective: in this work we report the molecular characterization of b-lactam antibiotics resistance conferred by genes contained in plasmids from enterobacteria producing extended-spectrum b-lactamases (esbl). material and methods: fourteen enterobacterial clinical isolates selected from a group of strains obtained from seven different hospitals in mexico during 1990-1992 and 1996-1998 were analyzed at the bacterial resistance laboratory (national institute public health, cuernavaca). molecular characterization included pfge, ief of b-lactamases, bacterial conjugation, pcr amplification and dna sequencing, plasmid extraction and restriction. results: isolates were genetically unrelated. esbl identified were shv-2 (5/14) and shv-5 (9/14) type. cephalosporin-resistance was transferable in 9 of 14 (64%) clinical isolates with only one conjugative plasmid, dna finger printing showed a similar band pattern in plasmids. conclusions: the dissemination of cephalosporin resistance was due to related plasmids carrying the esbl genes.
Genética y genómica enfocadas en el estudio de la resistencia bacteriana
Garza-Ramos,Ulises; Silva-Sánchez,Jesús; Martínez-Romero,Esperanza;
Salud Pública de México , 2009, DOI: 10.1590/S0036-36342009000900009
Abstract: bacterial resistance is a public health problem causing high rates of morbidity and mortality in hospital settings. to the extent that different antibiotics are used, bacteria resistant to multiple drugs are selected. the development of new molecular genomic and proteomic tools such as real-time pcr, dna pyrosequencing, mass spectrometry, dna microarrays, and bioinformatics allow for more in-depth knowledge about the physiology and structure of bacteria and mechanisms involved in antibiotic resistance. these studies identify new targets for drugs and design specific antibiotics to provide more accurate treatments to combat infections caused by bacteria. using these techniques, it will also be possible to rapidly identify genes that confer resistance to antibiotics, and to identify complex genetic structures, such as integrons that are involved in the spread of genes that confer multidrug-resistance.
Informe de los colectivos espa oles, argentinos y mexicanos nucleados en torno al tema “Filosofía y Judaísmo”
M., R.,Casalla, Mario,de la Garza, María Teresa
Isegoría , 2000,
Abstract:
INFLUENCE OF THE IMPLEMENTATION FACTORS IN THE INFORMATION SYSTEMS QUALITY FOR THE USER SATISFACTION
José Melchor Medina Quintero,Esther García Pedroche,María Isabel de la Garza Ramos
JISTEM - Journal of Information Systems and Technology Management , 2009,
Abstract: This research studies the influence range of the organizational, planning and technical factors within the information quality, system quality and information systems services quality, in the user satisfaction, based on the designed model research for this purpose. The empirical study takes place in six Higher Education Institutes (94 questionnaires) by the Partial Least Square statistic tool. The results has shown that Organizational Factor (information needs, management support, institutional objectives satisfaction) is which has the most impact because its high correlation value (R=0.624; R=0.435 yR=0.428) and signifi cance (p<0.001, p<0.01 and p<0.01) in the three raised hypotheses, taking into consideration an explained variance of 78.8% in the User Satisfaction. In the same way, with the quality in general, the users think that the information systems help to satisfy their information needs and increase their productivity into making decisions in their jobs.
Influencia de los factores de implementación en la calidad de los sistemas de información para la satisfacción del usuario
Quintero, José Melchor Medina;Pedroche, Esther García;Ramos, Ma. Isabel de la Garza;
JISTEM - Journal of Information Systems and Technology Management , 2009, DOI: 10.4301/S1807-17752009000100002
Abstract: this research studies the influence range of the organizational, planning and technical factors within the information quality, system quality and information systems services quality, in the user satisfaction, based on the designed model research for this purpose. the empirical study takes place in six higher education institutes (94 questionnaires) by the partial least square statistic tool. the results has shown that organizational factor (information needs, management support, institutional objectives satisfaction) is which has the most impact because its high correlation value (r=0.624; r=0.435 yr=0.428) and signifi cance (p<0.001, p<0.01 and p<0.01) in the three raised hypotheses, taking into consideration an explained variance of 78.8% in the user satisfaction. in the same way, with the quality in general, the users think that the information systems help to satisfy their information needs and increase their productivity into making decisions in their jobs.
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