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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.


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.


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.


Bosquez-Molina E.,Metropolitan Autonomous University | Tomas S.A.,Research Center Estudios Avanzados Ipn | Rodriguez-Huezo M.E.,Metropolitan Autonomous University
LWT - Food Science and Technology | Year: 2010

Oil-in-water (O/W) emulsions with a dispersed phase mass fraction (φm) of 0.175 were prepared by dispersing a blend of candelilla wax/mineral oil (2:1 ratio) in 10 g of mesquite gum per 100 g of water containing either CaCl2 (0.0, 0.1, 0.2, 0.3, 0.4 or 0.5 g) alone or combined with 1.5 g of glycerol. The mean volumetric droplet size (d3,0), the rate of droplet coalescence (C) and the viscosity-shear rate behavior of the emulsions were affected by the addition of CaCl2 alone or combined with glycerol. The Carreau-Yasuda model fitted best the viscosity-shear rate data of all the emulsions. The surface morphology of the edible films, analyzed by Atomic Force Microscopy (AFM), exhibited a strong dependence on the CaCl2 concentration. Maximum roughness occurred with a CaCl2 concentration of 0.3 g per 100 g. Films with glycerol showed significantly higher roughness than those with only CaCl2. Water vapor permeability (WVP) was significantly lowered as the concentration of CaCl2 increased from 0.1 to 0.3 g per 100 g in the coatings, but increased again at CaCl2 concentrations of 0.4-0.5 g per 100 g. Coatings containing glycerol displayed significant higher WVP. © 2010 Elsevier Ltd.


Romero-Montoya L.,Institute Servicios Periciales | Martinez-Rodriguez H.,Laboratorio Of Quimica Forense | Perez M.A.,Laboratorio Of Quimica Forense | Arguello-Garcia R.,Research Center Estudios Avanzados Ipn
Forensic Science International | Year: 2011

In the forensic laboratory the biological analyses for rape investigation commonly include vaginal swabs as sample material combined to biochemical tests including sperm cytology (SC) and detection of acid phosphatase activity (AP) and prostate-specific antigen (PSA, p30) for the conclusive identification of semen components. Most reports comparing these tests relied on analysis of semen samples or donor swabs taken under controlled conditions; however their individual or combined efficacy under real live sampling conditions in different laboratories is largely unknown. We carried out SC, APA and PSA analyses in vaginal swabs collected from casework rapes submitted to Mexican Forensic Laboratories at Texcoco and Toluca. On the basis of positive and negative results from each assay and sample, data were classified into eight categories (I-VIII) and compared with those obtained in the two only similar studies reported in Toronto, Canada and Hong Kong, China. SC and APA assays had the higher overall positivity in Toluca and Texcoco samples respectively and otherwise PSA had a lower but very similar positivity between these two laboratories. When compared to the previous studies some similarities were found, namely similar frequencies (at a ratio of approximately 1 out of 3) of samples being positive or negative by all techniques (Categories I and VI respectively) and a comparable overall positivity of APA and SC but higher than that of PSA. Indeed the combined results of using SC, APA and PSA tests was considered as conclusive for semen detection from approximately 1 out of 3 cases (Category I) to approximately 1 out of 2 cases in a scenario where at least SC is positive, strongly presumptive in 2 out of 3 cases (with at least one test positive) and the remainder 1 out of 3 cases (Category VI) suggested absence of semen. By determining Y-STR polymorphisms (12-loci) in additional samples obtained at Toluca laboratory, complete DNA profiles were determined from all Category I samples, none marker was detected from all Category VI samples and mostly partial profiles were obtained from samples of other categories. These observations give an overview on the variability in efficacy of each test performed at different laboratories and provide a general notion about the in praxis contribution of SC, APA and PSA tests for further DNA typing in the forensic analysis of rape. © 2010 Elsevier Ireland Ltd.


de los Santos-Villalobos S.,Research Center Estudios Avanzados Ipn | Barrera-Galicia G.C.,Research Center Estudios Avanzados Ipn | Miranda-Salcedo M.A.,Instituto Nacional Of Investigaciones Forestales Y Agropecuarias Inifap | Pena-Cabriales J.J.,Research Center Estudios Avanzados Ipn
World Journal of Microbiology and Biotechnology | Year: 2012

Colletotrichumgloeosporioides is the causal agent of anthracnose in mango. Burkholderiacepacia XXVI, isolated from mango rhizosphere and identified by 16S rDNA sequencing as a member of B. cepacia complex, was more effective than 6 other mango rhizosphere bacteria in inhibiting the model mango pathogen, C. gloeosporioides ATCC MYA 456. Biocontrol of this pathogen was demonstrated on Petri-dishes containing PDA by > 90 % reduction of surface colonization. The nature of the biocontrol metabolite(s) was characterized via a variety of tests. The inhibition was almost exclusively due to production of agar-diffusible, not volatile, metabolite(s). The diffusible metabolite(s) underwent thermal degradation at 70 and 121 °C (1 atm). Tests for indole acetic acid production and lytic enzyme activities (cellulase, glucanase and chitinase) by B. cepacia XXVI were negative, indicating that these metabolites were not involved in the biocontrol effect. Based on halo formation and growth inhibition of the pathogen on the diagnostic medium, CAS-agar, as well as colorimetric tests we surmised that strain XXVI produced a hydroxamate siderophore involved in the biocontrol effect observed. The minimal inhibitory concentration test showed that 0. 64 μg ml-1 of siderophore (Deferoxamine mesylate salt-equivalent) was sufficient to achieve 91. 1 % inhibition of the pathogen growth on Petri-dishes containing PDA. The biocontrol capacity against C. gloeosporioides ATCC MYA 456 correlated directly with the siderophore production by B. cepacia XXVI: the highest concentration of siderophore production in PDB on day 7, 1. 7 μg ml-1 (Deferoxamine mesylate salt-equivalent), promoted a pathogen growth inhibition of 94. 9 %. The growth of 5 additional strains of C. gloeosporioides (isolated from mango "Ataulfo" orchards located in the municipality of Chahuites, State of Oaxaca in Mexico) was also inhibited when confronted with B. cepacia XXVI. Results indicate that B. cepacia XXVI or its siderophore have the potential to be used as a biological control agent against C. gloeosporioides; thus diminishing environmental problems caused by the current practices to control this disease. © 2012 Springer Science+Business Media B.V.


Esquivel-Senties M.S.,Research Center Estudios Avanzados Ipn | Barrera I.,Research Center Estudios Avanzados Ipn | Ortega A.,Research Center Estudios Avanzados Ipn | Vega L.,Research Center Estudios Avanzados Ipn
Toxicology and Applied Pharmacology | Year: 2010

Diethyldithiophosphate (DEDTP) is a metabolite formed by biotransformation of organophosphorous (OP) compounds that has a longer half-life than its parental compound. Here we evaluate the effects of DEDTP on human CD4+ T lymphocytes. In vitro exposure to DEDTP (1-50μM) decreased [3H]thymidine incorporation in resting cells and increased CD25 surface expression without altering cell viability. DEDTP treatment inhibited anti-CD3/anti-CD28 stimulation-induced CD4+ and CD8+ T cell proliferation determined by CFSE dilution. Decreased CD25 expression and intracellular IL-2 levels were correlated with this defect in cell proliferation. IL-2, IFN-γ and IL-10 secretion were also reduced while IL-4 secretion was not altered. Increased phosphorylation of SOCS3 and dephosphorylation of STAT5 were induced by DEDTP after as little as 5min of exposure. In addition, DEDTP induced phosphorylation of ERK, JNK and p38 and NFAT nuclear translocation. These results suggest that DEDTP can modulate phosphorylation of intracellular proteins such as SOCS3, which functions as a negative regulator of cytokine signalling, and that DEDTP exposure may thus cause T cells to fail to respond to further antigen challenges. © 2010 Elsevier Inc.


Angulo-Bejarano P.I.,Research Center Estudios Avanzados Ipn | Paredes-Lopez O.,Research Center Estudios Avanzados Ipn
Scientia Horticulturae | Year: 2011

An indirect organogenesis regeneration protocol for Opuntia ficus-indica (L.) Mill var " Blanco sin Espinas" is described. One centimeter square cladode explants sections from previously micropropagated prickly pear plants were cultured in Murashige and Skoog (MS) basal medium supplemented with 20 different combinations of 2,4-dichlorophenoxy acetic acid (2,4-D) and benzyladenine (BA). The best calli induction and regeneration response were observed when 2.26 μM 2,4-D and 2.21 μM BA combination was applied to the nopal explants. Regenerating calli was capable of forming new buds when transferred to MS basal medium supplemented with 0.5 μM BA (proliferation medium). Shoot elongation and rooting were achieved on MS medium without plant growth regulators. Excellent acclimatization to greenhouse conditions was observed for all transferred plantlets. By this procedure no morphological differences were observed between the regenerated and mother plants. This protocol may be also utilized to carry out plant regeneration after genetic transformation, in order to develop transformed plants without the presence of chimeric zones. © 2011 Elsevier B.V.


Valverde M.E.,Research Center Estudios Avanzados Ipn | Hernandez-Perez T.,Research Center Estudios Avanzados Ipn | Paredes-Lopez O.,Research Center Estudios Avanzados Ipn
International Journal of Microbiology | Year: 2015

Mushrooms have been consumed since earliest history; ancient Greeks believed that mushrooms provided strength for warriors in battle, and the Romans perceived them as the "Food of the Gods." For centuries, the Chinese culture has treasured mushrooms as a health food, an "elixir of life." They have been part of the human culture for thousands of years and have considerable interest in the most important civilizations in history because of their sensory characteristics; they have been recognized for their attractive culinary attributes. Nowadays, mushrooms are popular valuable foods because they are low in calories, carbohydrates, fat, and sodium: also, they are cholesterol-free. Besides, mushrooms provide important nutrients, including selenium, potassium, riboflavin, niacin, vitamin D, proteins, and fiber. All together with a long history as food source, mushrooms are important for their healing capacities and properties in traditional medicine. It has reported beneficial effects for health and treatment of some diseases. Many nutraceutical properties are described in mushrooms, such as prevention or treatment of Parkinson, Alzheimer, hypertension, and high risk of stroke. They are also utilized to reduce the likelihood of cancer invasion and metastasis due to antitumoral attributes. Mushrooms act as antibacterial, immune system enhancer and cholesterol lowering agents; additionally, they are important sources of bioactive compounds. As a result of these properties, some mushroom extracts are used to promote human health and are found as dietary supplements. © 2015 María Elena Valverde et al.

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