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Flores-Villasenor H.,Autonomous University of Sinaloa | Canizalez-Roman A.,Autonomous University of Sinaloa | De La Garza M.,Research Center Estudios Avanzados Ipn | Nazmi K.,Academic Center for Dentistry Amsterdam | And 2 more authors.
Biochimie | Year: 2012

Enteropathogenic Escherichia coli (EPEC) is an important cause of infant diarrhea in developing countries. It produces a characteristic intestinal histopathological lesion on enterocytes known as 'attaching and effacing' (A/E), and these two steps are mediated by a type-III secretory system. In the present study, we evaluated the effect on the initial host cell attachment step produced by bovine lactoferrin (bLF) and three synthetic peptides: lactoferricin (LFcin), lactoferrampin (LFampin) and LFchimera. A special focus was given to the hemolytic activity and EPEC-induced actin polymerization in HEp-2 cells, as well as to the espA gene expression, which produces the protein responsible for primary contact with the host cells. Results show that EPEC attachment to HEp-2 cells was significantly suppressed by bLF and LFchimera at 125 and 40 μM, respectively. EPEC-mediated actin polymerization was blocked by bLF and LFchimera at 88 and 99%, respectively. LFchimera inhibited the attachment and A/E lesion caused by EPEC in a dose-dependent manner. In the presence of 125 μM bLF, the expression level of the espA gene was decreased by 50% compared to the untreated control. LFchimera at concentrations of 20 μM and 40 μM diminished the level of espA gene expression 100 and 1000 fold, respectively (P < 0.001). Although bLF, LFchimera, LFcin, and LFampin all significantly blocked the hemolysis produced by EPEC (P < 0.001), the two former compounds produced this effect at lower concentrations. These two compounds, bLF and LFchimera, were able to inhibit the first steps of the mechanism of the damage used by EPEC. This data suggests that LFchimera could provide protection against enteropathogens that share this mechanism. © 2012 Published by Elsevier Masson SAS. All rights reserved.

Gomez-Montiel N.O.,Instituto Nacional de Investigaciones Nucleares | Paredes-Lopez O.,Research Center Estudios Avanzados Ipn
LWT - Food Science and Technology | Year: 2011

Tortilla is the main staple of Mexico and it is made using diverse maize varieties, which have different endosperm types. Three maize varieties with vitreous, intermediate and floury endosperms were used. Texture and starch digestibility were evaluated in freshly prepared and stored tortillas for 24, 48 and 72 h. Tortilla made with maize of vitreous endosperm had the highest force to rupture and the lowest distance of elongation, indicating more rigid texture. Stored tortillas had lower available starch content and higher effect was shown by tortilla of vitreous endosperm, pattern that agrees with the higher increase in the resistant starch content with the storage time. Fresh tortilla of floury endosperm showed the highest hydrolysis rate during the first 15 min followed by tortillas of intermediate and vitreous endosperms. Starch hydrolysis values decreased when storage time increased, in agreement with the resistant starch content in the stored tortillas. At the longest storage time (72 h) tortilla of floury endosperm presented higher hydrolysis rate, followed by tortilla of intermediate and vitreous endosperms. The endosperm type plays an important role in the textural and starch digestibility of fresh and stored tortillas. © 2010 Elsevier Ltd.

Caspeta L.,National Autonomous University of Mexico | Caspeta L.,Chalmers University of Technology | Caro-Bermudez M.A.,National Autonomous University of Mexico | Ponce-Noyola T.,Research Center Estudios Avanzados Ipn | Martinez A.,National Autonomous University of Mexico
Applied Energy | Year: 2014

Agave bagasse is the lignocellulosic residue accumulated during the production of alcoholic beverages in Mexico and is a potential feedstock for the production of biofuels. A factorial design was used to investigate the effect of temperature, residence time and concentrations of acid and ethanol on ethanosolv pretreatment and enzymatic hydrolysis of agave bagasse. This method and the use of a stirred in-house-made mini-reactor increased the digestibility of agave bagasse from 30% observed with the dilute-acid method to 98%; also allowed reducing the quantity of enzymes used to hydrolyze samples with solid loadings of 30%. w/w and glucose concentrations up to 225. g/L were obtained in the enzymatic hydrolysates. Overall this process allows the recovery of 91% of the total fermentable sugars contained in the agave bagasse (0.51. g/g) and 69% of total lignin as co-product (0.11. g/g). The maximum ethanol yield under optimal conditions using an industrial yeast strain for the fermentation was 0.25. g/g of dry agave bagasse, which is 86% of the maximum theoretical (0.29. g/g). The effect of the glucose concentration and solid loading on the conversion of cellulose to glucose is discussed, in addition to prospective production of about 50. million liters of fuel ethanol using agave bagasse residues from the tequila industry as a potential solution to the disposal problems. © 2013 Elsevier Ltd.

Lopez-Soto F.,University of Sonora | Leon-Sicairos N.,Autonomous University of Sinaloa | Nazmi K.,Academic Center for Dentistry Amsterdam | Bolscher J.G.,Academic Center for Dentistry Amsterdam | De La Garza M.,Research Center Estudios Avanzados Ipn
BioMetals | Year: 2010

Entamoeba histolytica is a parasitic protozoan that produces amoebiasis, an intestinal disease characterized by ulcerative colitis and dysentery. In some cases, trophozoites can travel to the liver leading to hepatic abscesses and death. Recently, lactoferrin and lactoferricin B have been shown to be amoebicidal in axenic cultures. The aim of this work was to determine whether the lactoferrin-peptides lactoferricin amino acids 17-30, lactoferrampin amino acids 265-284, and lactoferrin chimera which is a fusion product of the two peptides, are capable of producing a microbicidal effect to trophozoites of E. histolytica. We evaluated the killing effect of these peptides in growth kinetics carried out in axenic culture medium to which different concentrations of peptides were added. At 50 μM of peptide concentration, lactoferricin and lactoferrampin had a moderate amoebicidal effect, since a 45-50% of trophozoites remained viable at 24 h culture. However, at 50 μM of the lactoferrin chimera 75% amoeba were killed whereas at 100 μM all cells died. These data indicate that of lactoferrin-peptides mainly the chimera have amoebicidal activity in a time- and concentration-dependent manner. The lactoferrin-peptides might be useful as therapeutic agents against amoebiasis and thereby diminish the use of metronidazole, which is extremely toxic for the host. © 2010 Springer Science+Business Media, LLC.

Paz-Maldonado M.T.,Research Center Estudios Avanzados Ipn | Arguello-Garcia R.,Research Center Estudios Avanzados Ipn | Cruz-Soto M.,Research Center Estudios Avanzados Ipn | Mendoza-Hernandez G.,National Autonomous University of Mexico | Ortega-Pierres G.,Research Center Estudios Avanzados Ipn
Infection, Genetics and Evolution | Year: 2013

In this study we performed proteomic and transcriptional analyses to identify and characterize genes differentially expressed in Giardia duodenalis clones resistant to albendazole. The expression of proteins and their corresponding mRNAs was analyzed in clones resistant in vitro to different concentrations of albendazole (1.35, 8.0 and 250. μM) and these were compared with albendazole-sensitive clones using two approaches: (1) two-dimensional protein electrophoresis to analyze the proteome by the LC-MS/MS technique, and (2) semi-quantitative RT-PCR to assess the mRNA levels of proteins with the highest levels of differential expression .This strategy allowed the identification of eight proteins differentially expressed in albendazole resistant clones with roles in: (a) the cytoskeletal system (alpha 2-giardin and RanBP1), (b) the antioxidant metabolism (NADH oxidase) and (c) energy metabolism (triosephosphate isomerase, phosphoglycerate kinase and ornithine carbamoyltransferase). Gene expression analyses of these genes correlated well with the proteomics results. These observations suggest that resistance to albendazole in Giardia encompasses a complex response involving an altered expression of genes regulated at the transcriptional level that might have an important role in maintaining cell structural stability, coping with oxidative stress and adapting energy supply to a new metabolic status. These molecules are indeed promising targets for drug development. © 2012 Elsevier B.V.

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