ABSTRACT
Resumen Los resultados a largo plazo del procedimiento de maze con criotermia en pacientes con fibrilación auricular durante procedimientos quirúrgicos concomitantes son todavía inciertos. Método Entre 2006 y 2011, 150 pacientes consecutivos con fibrilación auricular persistente y cardiopatía asociada fueron sometidos a cirugía de ablación mediante criotermia asociada a cirugía concomitante. El procedimiento de Cox-Maze biauricular fue realizado en 67 pacientes y ablación aislada de la aurícula izquierda en 83 pacientes. Los resultados a tres años en estos grupos fueron comparados mediante seguimiento clínico, electrocardiográfico y mediante Holter 24 horas y ecocardiografía con medición de la onda A transmitral al mes, a los 6 y 12 meses y después anualmente. Resultados Los pacientes sometidos a ablación Cox-Maze presentaron una libertad de fibrilación auricular del 97, 94, 89, 80 y 54% a 1, 6, 12, 24 y 36 meses respectivamente. En el seguimiento de los 12 meses estas diferencias resultaron significativas (p < 0.05). Como factor de riesgo de recurrencia de fibrilación auricular se identificó la ablación aislada de la aurícula izquierda. Conclusiones La ablación mediante criotermia tiene un elevado porcentaje de éxitos a dos años; la recurrencia se incrementa a partir de entonces independientemente de la técnica realizada. Para el tratamiento de la fibrilación auricular persistente asociada a otra patología quirúrgica cardiaca se debe realizar un tratamiento intensivo mediante ablación biauricular.
Abstract The long-term results of cryomaze in patients with longstanding persistent atrial fibrillation during concomitant surgical procedures are still uncertain. Methods Between 2006 and 2011, 150 consecutive patients with associated long-lasting permanent atrial fibrillation and associated heart disease underwent heart surgery were treated by biatrial Cox-Maze (63 patients) or by isolated endocardial or epicardial left atrial cryoablation (83 patients) concomitantly. The results at 3 years in these groups were compared with clinical monitoring, electrocardiography, 24-hour Holter, and echocardiography with measurement of the transmitral A wave at 1, 6 and 12 months and annually thereafter in all patients. Results Patients undergoing Cox-Maze IV ablation presented rates of freedom from atrial fibrillation of 97, 94, 89, 80 and 54% at 1, 6, 12, 24 and 36 months, respectively. In the 12-month follow-up, these differences were significant (p < .05). The independent risk factors of atrial fibrillation recurrence was isolated ablation of left atrium. Conclusions Atrial fibrillation by cryothermia ablation had a high success rate before 2 years postoperatively. Recurrence of atrial fibrillation increased thereafter regardless of the technique used, although it was more intense and developed earlier in cases of monoatrial ablation. For the treatment of other long-lasting permanent atrial fibrillation cardiac surgery-associated pathology, an aggressive biatrial treatment with Cox maze ablation should be performed.
Subject(s)
Humans , Male , Female , Aged , Atrial Fibrillation/surgery , Cryosurgery/methods , Heart Atria/surgery , Recurrence , Time Factors , Prospective Studies , Cardiac Surgical Procedures/methodsABSTRACT
El trabajo es resultado de un proceso prospectivo y estratégico de acompañamiento y empoderamiento local en 10 municipios de Norte de Santander, tendiente a identificar sus ventajas comparativas y proponer su transformación en ventajas competitivas, para formular visiones subregionales de desarrollo humano sostenible, bajo criterios participativos e incluyentes de grupos tradicionalmente segregados, como mujeres y jóvenes, mediante las cuales se puedan configurar espacios de integración subregional para asegurar un desarrollo endógeno y sinérgico del territorio.
The work is the result of a support and local empowerment prospective and strategic process in 10 municipalities of Norte de Santander, aimed to the identification of their comparative advantages and the proposal of their transformation into competitive advantages in order to formulate sustainable human development sub-regional visions under participatory and inclusive criteria of traditionally segregated groups such as women and youth, through which sub-regional integration spaces to ensure an endogenous and synergistic development of the territory can be possible to configure.
Subject(s)
Humans , Public Policy , Ecological Development , Community Integration , Sustainable DevelopmentABSTRACT
Changes in land use have generated a new landscape configuration in the Andino orobiome (mountain range) of the tropical Andes, resulting in a mosaic of cultivation and pastures interrupted by small fragments of forest and live fences. This has resulted in an ongoing decrease in the biodiversity of this biome. In the upper basin of the Cane-Iguaque River (Villa de Levya-Boyacá, Colombia), located 2 600-3 000 m above the Cordillera Oriental, over three time periods in 1960, 1984, and 2004, we characterized the structure, patterns, and evolution of the overall landscape and of the live fences (used as tools in biodiversity conservation and considered to be desirable alternatives to nonlive fences in farming production systems) within an agricultural landscape. To do this, we interpreted high- resolution satellite images using a landscape ecology approach and applied landscape map metrics. We found that the natural forests have been transformed by pastures and cultivation, and that although live fences cover only a small portion of the total landscape (4.6%), they have an important effect on landscape structure and biodiversity. There has been an increase in live fences, especially between 1960 and 1984, as well as an increase in their density. However, there has been a reduction in the average length of live fences over the periods that we studied. This could be due in part to changes in the types of agricultural products that have been cultivated in recent years, with an increase in potatoes and a decrease in other vegetables, and also by resource extraction of timber and fuel wood. In the studied area, agricultural production was sustained while biodiversity conservation was improved by the use of live fences. Therefore, live fences should be considered not only as part of an agriculturally productive area, but also as an important element of a multi-functional landscape that contributes to the maintenance of biodiversity and provides resources of economic and ecological interest, decreasing the pressure on natural forest. Improving the network of live fences constitutes an important strategy for the sustainable management of the rural landscape of the Andino orobiome of Colombia and similar areas in the tropics. Rev. Biol. Trop. 57 (4): 1183-1192. Epub 2009 December 01.
El cambio del uso del suelo ha generado una nueva configuración del paisaje en el Orobioma Andino de los Andes tropicales, dando lugar a un mosaico de cultivos y potreros interrumpidos por pequeños fragmentos de bosque y cercas vivas, con la disminución sobre la biodiversidad de este bioma. En la cuenca alta del río Cane- Iguaque (Boyaca-Colombia), ubicada entre 2 600-3 000 metros de altitud sobre la cordillera Oriental, se realizó un estudio de caracterización de estructura, patrones y evolución del paisaje y de las cercas vivas, en tres periodos 1960, 1984 y 2004, como herramienta para la conservación de la biodiversidad y alternativa en el manejo de los sistemas agrícolas. Se utilizó una metodología de interpretación de imágenes de satélite de alta resolución, bajo el enfoque de la ecología del paisaje y la utilización de métricas del paisaje. El bosque original esta altamente transformado por pastizales y cultivos, las cercas vivas ocupan apenas el 4.6% del área de estudio pero por su distribución se constituyen en elementos importantes para la biodiversidad. Se observa un incremento en las cercas vivas, entre los años 1960 y 1984. Sin embargo en este mismo período se da una disminución en la longitud, debido a la tendencia de aumento en el cultivo de papa y por la extracción de recursos de madera y leña. Para la zona de estudio es muy importante la producción agrícola y la conservación de la biodiversidad, y puede ser mejorada mediante la utilización de cercas vivas. Por tanto, las cercas deben considerarse como elementos multifuncionales del paisaje que contribuyen en el mantenimiento de la biodiversidad y aportan recursos de interés ecológico y económico, atenuando la presión sobre los bosques originales. El manejo adecuado y la mejora de la red de cercas vivas se constituyen en estrategias importantes para la gestión sostenible de paisaje rural de la zona andina colombiana.
Subject(s)
Agriculture , Ecosystem , Rivers , Biodiversity , Biomass , Colombia , Satellite CommunicationsABSTRACT
Telomerase is an enzyme that stabilizes telomere lenght in transformed cells and tumors. Its role in tumor development is far from clear. In this paper, a new experimental model to study telomerase activity during tumorigenesis is presented. After infection with Polyoma virus, AKR mice developed thymomas and mammary gland adenocarcinomas. Polyoma antigens were observed by the peroxidase-antiperoxidase technique on tissue sections, and by Western blot on tumor extracts. The TRAP assay was performed to detect telomerase activity. It was not present in normal mammary gland, but it was positive in mammary gland adenocarcinomas. A different pattern was seen in thymic tissues: normal thymus had higher telomerase activity than thymomas. The incubation of thymoma extracts with normal thymus extracts decreased telomerase activity in the latter. These results demonstrate two different patterns of telomerase activity in tumors induced by Polyoma virus, and suggest the presence of telomerase inhibitory factors in thymomas.