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Search Results: 1 - 10 of 14620 matches for " ISABEL; MORALES "
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Comparison of the Ability of Myricetin and Quercetin to Modulate the Oxidative DNA Damage Induced by Heterocyclic Amines  [PDF]
Ana Isabel Haza, Angel Lui Coto, Paloma Morales
Food and Nutrition Sciences (FNS) , 2011, DOI: 10.4236/fns.2011.24051
Abstract: The aim of the present study was to compare the ability of the myricetin and quercetin to modulate the oxidative DNA damage induced by 2-amino-3, 8- dimethylimidazo [4,5-f] quinoxaline (8-MeIQx), 2-amino- 3, 4, 8- trimethylimidazo [4, 5-f]-quinoxaline (4,8-diMeIQx) and 2-amino-1-methyl-6-phenyl-imidazo [4,5-b] pyridine (PhIP), in human hepatoma cells. DNA damage (strand breaks and oxidized purines/pyrimidines) was evaluated by the alkaline single-cell gel electrophoresis or comet assay. None of the myricetin and quercetin concentrations tested protected against 8-MeIQx, 4, 8-diMeIQx and PhIP-induced DNA strand breaks. The oxidized pyrimidines induced by 4, 8-diMeIQx and PhIP were reduced by myricetin but not by quercetin. Quercetin reduced the oxidized purines induced by 8-MeIQx and PhIP, while myricetin also reduced the induced by 4, 8-diMeIQx. One feasible mechanism by which myricetin and quercetin exert their protective effect towards HCAs-induced oxidative DNA could be related in part to the reduction of human CYP1A1. Another mechanism claimed to be responsible for the protective effect of myricetin and quercetin is the induction of phase II metabolizing enzymes such as UDP-glucuronyltrasferase (UGT). The ethoxyresorufin O-deethylation (CYP1A1) activity was moderately inhibited by myricetin, while little effect was observed by quercetin. On the contrary, quercetin showed the greatest increase on UDP-glucuronyltransferase activity. However, these are not the only mechanisms by which myricetin and quercetin exert their protective effect, other mechanisms such as stimulation of the repair of carcinogen-induced DNA damage and or the free radical scavenging efficiency have been also implicated. In conclusion, our results clearly indicate that myricetin was more efficient than quercetin to prevent DNA damage (oxidized purines and pyrimidines) induced by the three HCAs evaluated. This protective effect depends on the chemical structure of flavonoid and the mutagen studied.
Cariotipos fetales mediante amniocentesis y cordocentesis en Costa Rica
Perinatología y reproducción humana , 2004,
Abstract: objective: the identification of fetal abnormal chromosomes to allow proper pediatric and obstetric management of the cases as well as genetic counseling. material and methods: the results of 290 genetic amniocentesis from january 2000 to august 2003, are reported. there were two main reasons for referral: abnormal ultrasound assessment (44% of cases) and advanced maternal age (39%). most procedures (91%) were performed during the second trimester of pregnancy. fetal cells were closed cultured and suspension harvested. turn around time was 16 days median. g banded (300-400 bands resolution) chromosomes from 20 cells provided by two independent cultures were karyotyped in each case. the results of 18 genetic percutaneous umbilical cord samplings from january 2002 to august 2003, are also reported. almost all procedures were performed due to abnormal ultrasound findings from gestational week 17 to 35. results: in 230 fetal karyotypes obtained from amniotic fluid, 27 (12%) were abnormal, due to 12 autosomal trisomies , three cases of monosomy x, three mosaics involving chromosome x, three triploid karyotypes, two balanced translocations of maternal origin, one structurally abnormal chromosome and three other defects of sexual chromosomes in males. prenatal cytogenetic and sonographic findings correlated with the fetal or newborn phenotype in all cases available for follow-up. fetal abnormal chromosomes obtained from fetal blood were: two cases of trisomy 13, one fetus with trisomy 18, and one case of trisomy 21. conclusion: chromosome defects are an important reason for ultrasonographic fetal abnormalities and adverse pregnancy outcomes. normal results provided reassurance to the parents.
Disabilities caused by unstable mutations in Costa Rica
Cuenca,Patricia; Morales,Fernando; Castro,Isabel;
Revista de Biología Tropical , 2004,
Abstract: myotonic dystrophy and fragile x syndrome are two genetically determined relatively common disabilities. both are examples of a new type of mutation mechanism called unstable or dynamic mutations, triple repeats expansions or dna amplification. fragile x syndrome is recognized as the main cause of hereditary mental retardation and myotonic dystrophy is considered the most common muscular dystrophy of adults. this is a prospective non randomized study of clinically affected people, in order to confirm the diagnosis with molecular techniques (southern blot and pcr) and to perform cascade screening of the rest of the family to offer them adequate genetic counseling. we were able to corroborate the initial diagnosis in most clinical cases of myotonic dystrophy, but in the cases of mental retardation more than half studies were negative for fragile x syndrome, stressing the difficulties encountered by medical practitioners to diagnose this syndrome. the reasons for this are several; probable the main culprit is the subtle and unspecific clinical picture affected individuals exhibit, particularly children before puberty. cascade screening, genetic counseling and selective abortion are the only tools available to prevent these disabling diseases for the moment. rev. biol. trop. 52(3): 501-505. epub 2004 dic 15.
Comparación de las técnicas de análisis de variancia y regresión lineal múltiple: Aplicación a un experimento de almacenamiento de mango
Ileana Morales,María Isabel González
Agronomía Costarricense , 2003,
Abstract: Este estudio se propuso comparar 2 técnicas de análisis de datos: Análisis de variancia y regresión lineal múltiple, por medio de su aplicación para evaluar el efecto del empaque en películas flexibles, sobre el dulzor y el desarrollo de olores extra os en el mango var. Tommy Atkins durante el almacenamiento. El modelo de análisis de variancia ajustado no permite observar diferencias entre los niveles de los factores, sino solamente diferencias entre cada nivel y el promedio general. Permite observar si existen diferencias entre las pendientes de cada nivel y la pendiente general, y no brinda información del nivel utilizado como base al correr el modelo. El modelo de análisis de regresión múltiple permite observar diferencias entre cada nivel y el nivel utilizado como base, permite observar si existen diferencias entre las pendientes de cada nivel y la pendiente del nivel utilizado como base y brinda información acerca de todos los niveles del factor. Al evaluar el efecto de los 4 diferentes tipos de empaque, sobre las características de calidad del mango, se llega a la conclusión de que los empaques microperforado y termoencogible son los más adecuados. El empaque termoencogible resulta en menor desarrollo de olores extra os que el control, y ambos empaques resultan en niveles de dulzor iguales a los del control, no así los 2 polietilenos, en los que el dulzor aumenta con el tiempo, indicando una maduración más rápida que en el control.
Stem Cells as In Vitro Model of Parkinson's Disease
Patricia L. Martínez-Morales,Isabel Liste
Stem Cells International , 2012, DOI: 10.1155/2012/980941
Abstract: Progress in understanding neurodegenerative cell biology in Parkinson's disease (PD) has been hampered by a lack of predictive and relevant cellular models. In addition, the lack of an adequate in vitro human neuron cell-based model has been an obstacle for the uncover of new drugs for treating PD. The ability to generate induced pluripotent stem cells (iPSCs) from PD patients and a refined capacity to differentiate these iPSCs into DA neurons, the relevant disease cell type, promises a new paradigm in drug development that positions human disease pathophysiology at the core of preclinical drug discovery. Disease models derived from iPSC that manifest cellular disease phenotypes have been established for several monogenic diseases, but iPSC can likewise be used for phenotype-based drug screens in complex diseases for which the underlying genetic mechanism is unknown. Here, we highlight recent advances as well as limitations in the use of iPSC technology for modelling PD “in a dish” and for testing compounds against human disease phenotypes in vitro. We discuss how iPSCs are being exploited to illuminate disease pathophysiology, identify novel drug targets, and enhance the probability of clinical success of new drugs. 1. Introduction Parkinson’s disease (PD) is the second most common neurodegenerative disorder, characterized by a large number of motor and nonmotor features that can affect function in a variable degree. The main pathological hallmark in PD is the loss of midbrain dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc) projecting to the striatum and abnormal cytoplasmic inclusions enriched in α-synuclein, the Lewy bodies, deposited in surviving neurons of the brain [1–3]. There is no effective test for the diagnosis of PD; the disorder must be diagnosed based on clinical criteria. The main clinical features are tremor at rest (unilateral, prominent in the distal part of an extremity), rigidity (increased resistance to move), akinesia or bradykinesia (slowness of movement), postural instability, and other motor abnormalities. Other symptoms include secondary motor symptoms such as dystonia and dysphagia and nonmotor symptoms including cognitive abnormalities, sleep disorders, and pain [3]. Despite the research efforts in this area, with new and intriguing findings constantly being reported, at present, PD is still an incurable disease, but treatment can improve quality of life and functional capacity. To date, L-dopa in combination with a peripheral dopa decarboxylase inhibitor (benserazide or carbidopa) is the most effective
Colesterol, 7-cetocolesterol e 25-hidroxicolesterol em maionese
Morales-Aizpurúa, Isabel Cristina;Tenuta-Filho, Alfredo;
Ciência e Tecnologia de Alimentos , 2005, DOI: 10.1590/S0101-20612005000300017
Abstract: the antioxidant system used in mayonnaise production is efficient mainly in relation to oxidation of unsaturated fatty acids. consequently the shelf-life of the product is large (six months). however very little is known about the stability of cholesterol present in mayonnaise introduced with the eggs (raw material). the oxidation of cholesterol in mayonnaise was confirmed quantifying 7-ketocholesterol (7-keto) and 25-hydroycholesterol (25-oh) using hplc. the following occurrences were observed: 7-keto,1.99±0.59μg/g, in recently manufactured mayonnaise (approximately 15 days), 7-keto, 8.30±4.03 to 22.86±3.06μg/g, and 25-oh, 2.21±1.94 to 13.98±2.72μg/g, in mayonnaise samples (a,b,c,d and e) with 30 to 210 days after production, and 7-keto, 8.44±6.78μg/g, in mayonnaise samples collected at domiciles (products in use stored under refrigeration). the sum between 7-keto and 25-oh from a/e samples amounted to 2.07-4.94% in relation to cholesterol (50.66±3.08-73.36±3.53mg/100g). results here obtained are relevant in relation to deleterious biological activity attributed to cholesterol oxides and also by the technological aspects involved in mayonnaise manufacture.
Prevención de trastornos de alimentación: Un primer programa de prevención en dos fases
Casado Morales,María Isabel; Helguera Fuentes,Mayte;
Clínica y Salud , 2008,
Abstract: a program for the prevention of eating disorders was developed and implemented. the program is implemented in two stages, first there is a work with a group of high risk teenagers and then it is complemented with parent involvement. the work develops within the framework of indirect primary prevention -a key issue in this area since it is well known that these disorders are difficult to identify and that their nature entails concealment and refusal of help. hence, prevention is very effective since it addresses the risk factors associated to eating disorders. therefore, the emphasis of this work with adolescents and parents does not lie directly on modifying the risk behaviour but rather on providing personal strategies to minimize the effect of risk factors associated with eating disorders.
óxidos de colesterol: ocorrência em alimentos, forma??o e efeitos biológicos
Morales-Aizpurúa, Isabel Cristina;Tenuta-Filho, Alfredo;
Revista Brasileira de Ciências Farmacêuticas , 2002, DOI: 10.1590/S1516-93322002000400005
Abstract: important points involving the occurrence of cholesterol oxides -cos- in foods, formation mechanisms and biological activities of these compounds associated to cytotoxic, angiotoxic, atherogenic, mutagenic and carcinogenic processes were reviewed. the individual and/or total cos levels detected in foods were considered of potential risk for health. it was also considered necessary to determine the implication of cos from dietary sources in relation to endogenous cos formed metabolically. inhibition of the cholesterol oxidation in foods to prevent the ingestion of these oxides was emphasized.
Repensando desde el plano normativo la participación ciudadana en la gestión pública*
Morales,Eduviges; Nú?ez,Ingrid; Delfín,María Isabel;
Revista Venezolana de Gerencia , 2006,
Abstract: after promulgating the constitution of the bolivarian republic of venezuela in 1999, a new paradigm in the conceptualization, organization and functioning of the state was consecrated, which subsequently effected a change in the management mechanisms of public affairs. the objective of this paper is to study on a normative plane, citizen participation as a mechanism and instrument that permits the integration of organized communities in the processes of public sector management. the methodology utilized is documentary since it is based on a review of national and foreign doctrine and constitutional and legal norms derived from the constitution, in order to analyze the relation state-society, in view of the inter-relations generated by the new framework imposed by the venezuelan positive judicial ordering. the conclusion is that sufficient normative elements are present in order to strengthen and give feedback as to the participative variable in the functioning of state affairs, on all levels and in all stages, from design to execution, and the definitive control of the execution, taking into account citizen participation in budgeting and in the control of execution in national, state and local planning councils.
Lineas base, dosis diagnostico y medicion periodica de resistencia a imidacloprid, spinosad y carbosulfan en poblaciones de adultos de Thrips palmi (Thysanoptera: Thripidae) en el Valle del Cauca, Colombia
Revista Colombiana de Entomología , 2003,
Abstract: the melon thrips (thrips palmi) have become a very significant pest of snap beans, beans, eggplants and cucumbers, and other crops, since they were first reported in colombia. the response of farmers to this problem has been the excessive pesticide use. with the aim of monitoring changes on the susceptibility of thrips populations to certain insecticides that are still effective, the line base data, lc50and lc90 values and diagnostic doses for imidacloprid, spinosad and carbosulfan were established. we used an adult population of a susceptible strain of t. palmi maintained at ciat since 1997. imidacloprid was evaluated as a systemic pesticide by immersing leaves with petioles in insecticide solutions. disks of foliage treated in this fashion were placed on agar in petri dishes. spinosad and carbosulfan were evaluated as contact pesticides using the foliage dipping technique. disks of the treated foliage were placed on petri dishes with agar. the diagnostic doses were 1.000 ppm (imidacloprid), 2.000 ppm (spinosad) and 2.000 ppm (carbosulfan). these doses were used for field monitoring of resistance in five zones of the cauca valley where heavy use of pesticides for the control of t. palmi occurs. no evidence of resistance to any of the evaluated pesticides was found. nevertheless, we recommended the performance of periodic monitoring in order to detect changes in resistance of the thrips over time.
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