Paisajes patrimoniales. Resiliencia, resistencia y metrópoli en América Latina

249 páginas.La propuesta de esta obra, es que el estudio del paisaje no se basa sólo en la observación panorámica del territorio, sino trata de profundizar en el hecho cultural, que va más allá de su percepción meramente estética o vivencial, desde donde podamos aprehenderlo, como la construcción social que configura el entorno. Para ello el investigador necesita desentrañar las narrativas en las que se envuelven los actores en los escenarios territoriales, lo cual implica generar una visión crítica de cómo un paisaje patrimonial ha sido imaginado y constituido. Es con esta mirada que cuestionamos la conformación de los territorios, ya que el objetivo es asumir posturas y preguntarnos ¿existen paisajes resilientes? ¿Cómo reconocer paisajes en resistencia? ¿Cuál es el paisaje que queremos dejar a las futuras generaciones? Para responder a estas interrogantes, que además se han vuelto una preocupación social creciente, surgió la idea de editar esta publicación, la cual recoge una selecta recopilación de trabajos presentados en la 4ta. Jornada de Paisajes Patrimoniales “Resistencia, resiliencia y metrópoli en América Latina”, convocada por la Benemérita Universidad Autónoma de Puebla y la Red Mexicana de Estudios sobre Paisajes Patrimoniales y llevada a cabo en octubre de 2017 en la Universidad Autónoma Metropolitana. El objetivo principal, fue reflexionar sobre la resiliencia y la resistencia en el contexto metropolitano desde una óptica latinoamericana. La línea de la obra que tiene en sus manos se centra en la importancia de preservar territorios, cuyos valores históricos, culturales e identitarios se encuentran, ya sea en peligro de desaparecer o en vías de recuperación. Asimismo, se plantea la problemática sobre cómo diferentes sectores de la sociedad se encuentran resistiendo los embates del turismo, la gentrificación, los megaproyectos de extracción de los recursos naturales, la especulación inmobiliaria o el abandono de nuestros paisajes. Las propuestas se han dividido en cuatro apartados, el primero es de corte teórico conceptual y metodológico, en la escala que va de lo nacional a lo regional-local; el segundo agrupa aspectos como el paisaje natural en una zona metropolitana y el valor patrimonial de unidades agro productivas en una dimensión geográfica centrada en dos entidades federativas localizadas en la región central de México. El tercer apartado comprende trabajos cuyo hilo conductor es el recurso agua, como parte fundamental del desarrollo, económico y cultural de las comunidades y finalmente, el cuarto se refiere a contribuciones que incorporan esquemas propositivos para la gestión de los paisajes patrimoniales, así como el análisis del paisaje patrimonial ante el embate del capital.Armando Alonso Navarrete, Mariano Castellanos Arenas, coordinadores

The ytkD (mutTA) Gene of Bacillus subtilis Encodes a Functional Antimutator 8-Oxo-(dGTP/GTP)ase and Is under Dual Control of Sigma A and Sigma F RNA Polymerases

The regulation of expression of ytkD, a gene that encodes the first functional antimutator 8-oxo-dGTPase activity of B. subtilis, was studied here. A ytkD-lacZ fusion integrated into the ytkD locus of wild-type B. subtilis 168 revealed that this gene is expressed during both vegetative growth and early stages of sporulation. In agreement with this result, ytkD mRNAs were detected by both Northern blotting and reverse transcription-PCR during both developmental stages. These results suggested that ytkD is transcribed by the sequential action of RNA polymerases containing the sigma factors σ(A) and σ(F), respectively. In agreement with this suggestion, the spore-associated expression was almost completely abolished in a sigF genetic background but not in a B. subtilis strain lacking a functional sigG gene. Primer extension analysis mapped transcriptional start sites on mRNA samples isolated from vegetative and early sporulating cells of B. subtilis. Inspection of the sequences lying upstream of the transcription start sites revealed the existence of typical σ(A)- and σ(F)-type promoters. These results support the conclusion that ytkD expression is subjected to dual regulation and suggest that the antimutator activity of YtkD is required not only during vegetative growth but also during the early sporulation stages and/or germination of B. subtilis. While ytkD expression obeyed a dual pattern of temporal expression, specific stress induction of the transcription of this gene does not appear to occur, since neither oxidative damage (following either treatment with paraquat or hydrogen peroxide) nor mitomycin C treatment or σ(B) general stress inducers (sodium chloride, ethanol, or heat) affected the levels of the gene product produced

Obtención de Variantes Hiperactivas e Inactivas de la Endocelulasa Cel9 de Myxobacter Sp. Al-1 Obtención de Variantes Hiperactivas e Inactivas de la Endocelulasa Cel9 de Myxobacter Sp. Al-1

Debido a su aplicación industrial, existe un gran interés en la producción de celulasas con propiedades bioquímicas novedosas. Por ello, en el presente trabajo se utilizó una estrategia basada en un método de mutagénesis aleatoria in vivo para la obtención de variantes de la endocelulasa Cel9 del microorganismo gram-negativo Myxobacter Sp. AL-1. Siguiendo este enfoque, se obtuvieron cepas transformantes de Escherichia coli capaces de secretar variantes de la proteína Cel9 cuyas actividades específicas fueron incrementadas hasta 7.5 veces con respecto a la actividad mostrada por la enzima nativa. Del mismo modo, se generaron cepas de E. coli productoras de variantes de la proteína Cel9 con baja o nula actividad enzimática. Experimentos de subclonación y fraccionamiento celular revelaron que las mutaciones asociadas con los fenotipos de las variantes de la enzima Cel9 ocurrieron en la secuencia del gen cel9. Así mismo, se demostró que los fenotipos de las cepas mutantes carentes de actividad enzimática no dependen de su incapacidad para secretar las proteínas mutantes. Además de su potencial aplicación biotecnológica, los resultados obtenidos en este trabajo permiten avanzar en el entendimiento de la relación estructura-función de la celulasa Cel9 de Myxobacter Sp. AL-1.Due to its biotechnological impact, there is currently a growing interest in the production of cellulases with novel biochemical properties. Here, multiple generations of random mutagenesis in vivo and screening were employed to generate variants of the modular cellulase Cel9 from Myxobacter Sp. AL-1. Following this approach, Cel9 variants which showed increases upto 7.5 fold of cellulase activity were obtained. In addition, Cel9 mutants which completely lost the ability to degrade cellulose were also obtained. Results revealed that mutations associated with the phenotype of the Cel9 variants occurred on the mutant gene sequence and that themutants with null or reduced activity did not accumulate in the cell. In addition to the potential biotechnological application of the enzymes with improved activity obtained here, the results of this work will contribute to the understanding of the structure and function of cellulases grouped in the family 9 of glycosyl hydrolases

YtkD and MutT Protect Vegetative Cells but Not Spores of Bacillus subtilis from Oxidative Stress

ytkD and mutT of Bacillus subtilis encode potential 8-oxo-dGTPases that can prevent the mutagenic effects of 8-oxo-dGTP. Loss of YtkD but not of MutT increased the spontaneous mutation frequency of growing cells. However, cells lacking both YtkD and MutT had a higher spontaneous mutation frequency than cells lacking YtkD. Loss of either YtkD or MutT sensitized growing cells to hydrogen peroxide (H(2)O(2)) and t-butylhydroperoxide (t-BHP), and the lack of both proteins sensitized growing cells to these agents even more. In contrast, B. subtilis spores lacking YtkD and MutT were not sensitized to H(2)O(2), t-BHP, or heat. These results suggest (i) that YtkD and MutT play an antimutator role and protect growing cells of B. subtilis against oxidizing agents, and (ii) that neither YtkD nor MutT protects spores against potential DNA damage induced by oxidative stress or heat

Effects of Continuous and Interval Training on Running Economy, Maximal Aerobic Speed and Gait Kinematics in Recreational Runners

The purpose of this study was to evaluate the effects on running economy (RE), Vo 2 max, maximal aerobic speed (MAS), and gait kinematics (step length [SL] and frequency, flight and contact time [CT]) in recreational athletes, with 2 different training methods, Interval and Continuous (CON). Eleven participants were randomly distributed in an interval training group (INT; n 6) or CON training group (CON; n 5). Interval training and CON performed 2 different training programs (95-110% and 70-75% of MAS, respectively), which consisted of 3 sessions per week during 6 weeks with the same external workload (%MAS × duration). An incremental test to exhaustion was performed to obtain Vo 2 max, MAS, RE, and gait variables (high speed camera) before and after the training intervention. There was a significant improvement (p ≤ 0.05) in RE at 60 and 90% of MAS by the CON group; without changes in gait. The INT group significantly increased MAS and higher stride length at 80, 90, and 100% of MAS and lower CT at 100% of MAS. As expected, training adaptations are highly specific to the overload applied with CON producing improvements in RE at lower percentage of MAS whereas INT produces improvements in MAS. The significantly increased stride length and decreased CT for the INT group are an important outcome of favorable changes in running gait

Polymorphisms in DNA Repair Genes (APEX1, XPD, XRCC1 and XRCC3) and Risk of Preeclampsia in a Mexican Mestizo Population

Variations in genes involved in DNA repair systems have been proposed as risk factors for the development of preeclampsia (PE). We conducted a case-control study to investigate the association of Human apurinic/apyrimidinic (AP) endonuclease (APEX1) Asp148Glu (rs1130409), Xeroderma Pigmentosum group D (XPD) Lys751Gln (rs13181), X-ray repair cross-complementing group 1 (XRCC) Arg399Gln (rs25487) and X-ray repair cross-complementing group 3 (XRCC3) Thr241Met (rs861539) polymorphisms with PE in a Mexican population. Samples of 202 cases and 350 controls were genotyped using RTPCR. Association analyses based on a χ2 test and binary logistic regression were performed to determine the odds ratio (OR) and a 95% confidence interval (95% CI) for each polymorphism. The allelic frequencies of APEX1 Asp148Glu polymorphism showed statistical significant differences between preeclamptic and normal women (p = 0.036). Although neither of the polymorphisms proved to be a risk factor for the disease, the APEX1 Asp148Glu polymorphism showed a tendency of association (OR: 1.74, 95% CI = 0.96–3.14) and a significant trend (p for trend = 0.048). A subgroup analyses revealed differences in the allelic frequencies of APEX1 Asp148Glu polymorphism between women with mild preeclampsia and severe preeclampsia (p = 0.035). In conclusion, our results reveal no association between XPD Lys751Gln, XRCC Arg399Gln and XRCC3 Thr241Met polymorphisms and the risk of PE in a Mexican mestizo population; however, the results in the APEX1 Asp148Glu polymorphism suggest the need for future studies using a larger sample size

Variación en la tolerancia a desinfectantes de genotipos élite de "coffea" spp. cultivados "in vitro"

The somatic embryogenesis can be affected by explants' oxidation when a common method of disinfection is. In the Experimental Field Rosario Izapa in 2006, the tolerance to disinfectants of leaf explants of coffee genotypes was determined by the median lethal dose (LD50) and based on its tolerance the optimal disinfectant for aseptic establishment was defined. The LD50 of sodium hypochlorite (NaClO), calcium hypochlorite (Ca[ClO]2) and the combination of both in leaf explants of Coffea canephora P. genotypes (INIFAP 95-8, 95-9, 97-10, 97-12, 97-15, 97-18, 97-19, 97-20, 00-24 and 00-28) and genotypes of C. arabica L. (INIFAP 2000- 1018, 2000-1128 and 2000-692), was determined by applying eight concentrations of NaClO (0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5%), eight concentrations of Ca(ClO )2 (3, 4, 5, 6, 7, 8, 9 and 10%) and the combination. Based on the tolerance, disinfection treatments were applied, 1, 3 and 6% of NaClO, 3.5, 7 and 10.5% of Ca (ClO)2 and control¿s combination of 3 and 7% NaClO and Ca(ClO)2, respectively. There was variability in the tolerance, since LD50 varied depending on genotype and disinfecting agent. Most genotypes were less tolerant to NaClO (LD50 from 2 to 4%), however, NaClO controlled pollution andoxidation at low doses (1 and 3%). NaCl and Ca(ClO)2 at low concentrations up to 2 and 3.5% respectively, these are an option for coffee explants disinfection that can ensure proper physiological state to initiate the embryogenesis.La embriogénesis somática puede ser afectada por la oxidación de los explantes al aplicar un método común de desinfección. En el Campo Experimental Rosario Izapa en 2006, se determinó la tolerancia a desinfectantes de explantes foliares de genotipos de café, mediante la dosis letal media (DL50) y con base en la tolerancia, se definió el desinfectante óptimo para el establecimiento aséptico. La DL50 de hipoclorito de sodio (NaClO), de hipoclorito de calcio (Ca[ClO]2) y la combinación de ambos, en explantes foliares de genotipos de Coffea canephora P. (INIFAP 95-8, 95-9, 97-10, 97-12, 97-15, 97-18, 97-19, 97-20, 00-24 y 00-28) y genotipos de C. arabica L. (INIFAP 2000-1018, 2000-1128 y 2000-692), se determinó mediante la aplicación de ocho concentraciones de NaClO (0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5%), ocho concentraciones de Ca(ClO)2 (3, 4, 5, 6, 7, 8, 9 y 10%) y la combinación. Con base en la tolerancia se aplicaron tratamientos de desinfección: 1, 3 y 6% de NaClO, 3.5, 7 y 10.5% de Ca(ClO)2 y la combinación testigo de 3 y 7% de NaClO y Ca(ClO)2, respectivamente. Existió variabilidad en la tolerancia, puesto que la DL50 varió dependiendo del genotipo y el agente desinfectante. La mayoría de los genotipos fueron menos tolerantes al NaClO (DL50 de 2 a 4%); no obstante, el NaClO controló la contaminación y oxidación en dosis bajas (1 y 3%). El NaClO y el Ca(ClO)2 en bajas concentraciones de hasta 2 y 3.5% respectivamente, son una opción para la desinfección de explantes de café que pueden garantizar un estado fisiológico adecuado para dar inicio a la embriogénesis

Desarrollo y validación externa de un modelo pronóstico precoz para supervivientes de una parada cardiaca extrahospitalaria

Introduction and objectives: Despite therapeutic hypothermia, unconscious survivors of out-of-hospital cardiac arrest have a high risk of death or poor neurologic function. Our objective was to assess the usefulness of the variables obtained in the early moments after resuscitation in the prediction of 6-month prognosis. Methods: A multicenter study was performed in 3 intensive cardiac care units. The analysis was done in 153 consecutive survivors of out-of-hospital cardiac arrest who underwent targeted temperature management between January 2007 and July 2015. Significant neurological sequelae at 6 months were considered to be present in patients with Cerebral Performance Categories Scale > 2. An external validation was performed with data from 91 patients admitted to a third hospital in the same time interval. Results: Among the 244 analyzed patients (median age, 60 years; 77.1% male; 50.0% in the context of acute myocardial ischemia), 107 patients (43.8%) survived with good neurological status at 6 months. The prediction model included 5 variables (Shockable rhythm, Age, Lactate levels, Time Elapsed to return of spontaneous circulation, and Diabetes – SALTED) and provided an area under the curve of 0.90 (95%CI, 0.85-0.95). When external validation was performed, the predictive model showed a sensitivity of 73.5%, specificity of 78.6%, and area under the curve of 0.82 (95%CI, 0.73-0.91). Conclusions: A predictive model that includes 5 clinical and easily accessible variables at admission can help to predict the probability of survival without major neurological damage following out-of-hospital cardiac arrest.Introducción y objetivos: A pesar del uso de la hipotermia terapéutica, los pacientes recuperados tras sufrir una parada cardiaca extrahospitalaria tienen un elevado riesgo de muerte o deterioro neurológico grave. Se analizaron la utilidad de diversas variables disponibles al ingreso hospitalario para predecir su evolución a los 6 meses. Métodos: Se desarrolló un estudio multicéntrico en 3 unidades de cuidados intensivos cardiacos. El análisis se realizó sobre 153 pacientes ingresados en dos centros tras sufrir una parada cardiaca extrahospitalaria recuperada y que se trataron con control de temperatura, entre enero de 2007 y julio de 2015. Se consideraron secuelas neurológicas significativas si la Cerebral Performance Categories Scale > 2 a los 6 meses. Los resultados se validaron externamente con los datos procedentes de otros 91 pacientes ingresados en un tercer hospital, durante el mismo periodo de tiempo. Resultados: Del total de 244 pacientes (mediana de edad, 60 años; 77,1% varones; 50,0% en el contexto de isquemia miocárdica aguda), 107 (43,8%) sobrevivieron a los 6 meses con una evolución neurológica favorable. Se calculó un modelo predictivo que incluyó 5 variables (primer ritmo, edad, lactato al ingreso, tiempo hasta recuperación de circulación espontánea y diabetes), con un área bajo la curva de 0,90 (IC95%, 0,85-0,95). Cuando se realizó la validación externa del modelo, la sensibilidad fue de 73,5%, con una especificidad de 78,6% y un área bajo la curva de 0,82 (IC95%, 0,73-0,91). Conclusiones: Un modelo predictivo que incluye cinco variables disponibles en el momento de ingreso de pacientes recuperados tras sufrir una parada cardiaca extrahospitalaria puede ayudar a predecir la probabilidad de supervivencia libre de secuelas neurológicas graves en el seguimiento.Sin financiación4.642 JCR (2019) Q1, 30/138 Cardiac & Cardiovascular Systems0.473 SJR (2019) Q3, 196/362 Cardiology and Cardiovascular MedicineNo data IDR 2019UE

Evaluación clínica, bioquímica, endoscópica e histopatológica del tratamiento biológico de colitis ulcerativa: Clinical, biochemical, endoscopic and histopathological evaluation of biological treatment in ulcerative colitis

Background: Biological treatment is currently used as an alternative for the treatment of ulcerative colitis in patient’s refractory to conventional treatment. Objective: To evaluate biological treatment in patients with ulcerative colitis refractory to conventional treatment in a 3rd level care Hospital. Methods: A descriptive, retrospective, longitudinal study was carried out in patients with UC who were refractory to conventional treatment and who received biological treatment. The variables were evaluated in 3 moments: basal state (without biological treatment), at six and twelve months from the start of biological treatment. Descriptive statistics were used to characterize general population, later the 3 states mentioned above were described with their respective variables. Results: Eighteen patients with a mean age of 41.2 years were included. Evaluations at baseline and at 6 and 12 months showed: presence of blood in stools and abdominal pain in 94.4%%, 22.2% and 11.1% respectively; hemoglobin concentration >10.5 g/dl in 50%, 83.3% and 88.9%; serum albumin concentration >3.2 g/dl in 72.2%, 83.3% and 88.9%; the visual Mayo endoscopic scale 38.9%, 33.3% and 16.7% presented Mayo 2 and 61.1%, 16.7% and 1.7% Mayo 3. The histological activity in the baseline evaluation reached a severe level (11.1%), while in evaluations at 6 and 12 months they reached moderate in 55.6% and 27.8% respectively. Conclusions: Biological therapy as a treatment in patients with ulcerative colitis showed improvement in clinical, biochemical, endoscopic and histological manifestations, so far none with deep remission of the disease, no adverse reactions to treatment have been presented.Introducción: El tratamiento biológico es una alternativa para manejar la colitis ulcerativa en pacientes refractarios al tratamiento convencional. Objetivo: Evaluar el tratamiento biológico en pacientes con colitis ulcerativa refractarios al tratamiento convencional en un hospital de 3er nivel de atención. Métodos: Estudio descriptivo, retrospectivo, longitudinal en pacientes con colitis ulcerativa refractarios al tratamiento convencional y que recibieron tratamiento biológico. Las cortes se evaluaron en tres momentos: estado basal (sin terapia biológica), a los seis y doce meses de inicio del tratamiento biológico. Se utilizó estadística descriptiva para la caracterización de la población en general, posteriormente los tres puntos de corte se describieron con sus respectivas variables. Resultados: Se incluyeron 18 pacientes con edad media de 41,2 años. Las evaluaciones, en un estado basal, a los seis y 12 meses; demostraron presencia de sangre en las evacuaciones y dolor abdominal en 94,4%, 22,2% y 11,1% respectivamente, concentración de hemoglobina >10,5 g/dl en 50%, 83,3% y 88,9%; concentración sérica de albúmina >3,2 g/dl en 72,2%, 83,3% y 88,9% y escala visual endoscópica de Mayo 38,9%, 33,3% y 16,7% presentaron Mayo 2 y 61,1%, 16,7% y 1,7% Mayo 3. La actividad histológica en la evaluación basal llego hasta un nivel severo (11,1%), mientras que en evaluaciones a seis y 12 meses llegaron hasta moderada en un 55,6% y 27,8% respectivamente. Conclusiones: La terapia biológica en pacientes con colitis ulcerativa refractaria demostró mejoría en manifestaciones clínicas, bioquímicas, endoscópicas e histológicas. No se registró remisión profunda de la enfermedad, ni reacciones adversas al tratamiento

Association between Blood Lead Levels and Delta-Aminolevulinic Acid Dehydratase in Pregnant Women

Blood lead levels (BLLs) and delta-aminolevulinic acid dehydratase (ALAD) activity are considered biomarkers of lead exposure and lead toxicity, respectively. The present study was designed to investigate the association between BLLs and ALAD activity in pregnant women from Durango, Mexico. A total of 633 pregnant women aged 13–43 years participated in this study. Blood lead was measured by a graphite furnace atomic absorption spectrometer. ALAD activity was measured spectrophotometrically. Mean blood lead was 2.09 ± 2.34 µg/dL; and 26 women (4.1%) crossed the Centers for Disease Control (CDC) recommended level of 5 µg/dL. ALAD activity was significantly lower in women with levels of lead ≥5 µg/dL compared to those with BLLs < 5 µg/dL (p = 0.002). To reduce the influence of extreme values on the statistical analysis, BLLs were analyzed by quartiles. A significant negative correlation between blood lead and ALAD activity was observed in the fourth quartile of BLLs (r = −0.113; p < 0.01). Among women with blood lead concentrations ≥2.2 µg/dL ALAD activity was negatively correlated with BLLs (r = −0.413; p < 0.01). Multiple linear regression demonstrated that inhibition of ALAD in pregnant women may occur at levels of lead in blood above 2.2 µg/dL