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To determine the role of the cystine/glutamate antiporter on retinal structure and function, retinas of C57Bl/6J wild-type and xCT knockout mice, lacking the xCT subunit of the cystine/glutamate antiporter were examined from 6 weeks to 12 months of age. Fundoscopy, optical coherence tomography (OCT), and whole mount retinal autofluorescence imaging were used to visualise age-related retinal spots. Glial fibrillary acidic protein (GFAP) immunolabelling was used to assess retinal stress. Retinal function was evaluated using full-field and focal electroretinograms. Examinations revealed retinal spots in both wild-type and xCT knockout mice with the number of spots greater at 9 months in the knockout compared to wild-type. OCT confirmed these discrete spots were located at the retinal pigment epithelium (RPE)-photoreceptor junction and did not label with drusen markers. Whole mount lambda scans of the 9 month xCT knockout retinas revealed that the photoreceptor autofluorescence matched the spots, suggesting these spots were retinal debris. GFAP labelling was increased in knockout retinas compared to wild-type indicative of retinal stress, and the discrete spots were associated with migration of microglia/macrophages to the RPE-retina intersection. OCT revealed that the superior retina was thinner at 9 months in knockout compared to wild-type mice due to changes to the outer nuclear and photoreceptor layers. While global retinal function was not affected by loss of xCT, focal changes in retinal function were detected in areas where spots were present. Tother these results suggest that the xCT KO mice exhibit features of accelerated ageing and suggests that this mouse model may be useful for studying the underlying cellular pathways in retinal ageing.

espanolLa integracion de varias posturas ideologicas de la comunidad academica en torno a los grandes problemas que afronta el planeta ha permitido establecer un complejo sistema de relaciones practicas y teoricas entre el hombre y la naturaleza, generando una fuerte conexion entre desarrollo sostenible y desarrollo humano, y confiriendo mayor prominencia al papel de los seres humanos, de acuerdo a sus poderes, libertades, y acciones para alcanzar y maximizar su bienestar individual y colectivo. En este sentido, el proposito de este capitulo es analizar la influencia del contexto humano en la conceptualizacion historica del desarrollo y su relacion con el bienestar humano y planetario durante los ultimos 50 anos. Intentamos comprobar que cuando se trata del desarrollo desde una perspectiva humana o desde la perspectiva de la sostenibilidad, se tiende hacia un mismo discurso que posibilita la convergencia y evolucion del concepto de desarrollo hacia una tendencia mucho menos utopica, con mayor alcance y aplicacion bajo el paradigma cientifico de sostenibilidad en terminos de bienestar humano. EnglishThe integration of the various ideological views by the academic community around the great problems facing the planet has allowed the establishment of a complex system of practical and theoretical relationships between man and nature, generating a strong connection between sustainable development and human development, and conferring greater prominence to the role of human beings, according to their powers, liberties and actions for achieving and maximizing their individual and collective well-being. In this regard, this chapter aims to analyze the influence of the human context in the historical conceptualization of development and its relation with human and planetary well-being over the past 50 years. We try to prove that when it comes to development from the human perspective or from the perspective of sustainability, it tends towards the same discourse that enables convergence and evolution of the concept of development into a much less utopian trend, with greater scope and application under the scientific paradigm of sustainability in terms of human welfare. portuguesA integracao de varias posturas ideologicas da comunidade academica em torno aos grandes problemas que afronta o planeta ha permitido estabelecer um complexo sistema de relacoes praticas e teoricas entre o homem e a natureza, gerando uma forte conexao entre desenvolvimento sustentavel e desenvolvimento humano, e conferindo maior prominencia ao papel dos seres humanos, de acordo aos seus poderes, liberdades, e acoes para alcancar e maximizar seu bem-estar individual e coletivo. Neste sentido, o proposito deste capitulo e analisar a influencia do contexto humano na conceptualizacao historica do desenvolvimento e sua relacao com o bem-estar humano e planetario durante os ultimos 50 anos. Tentamos comprovar que quando se trata do desenvolvimento desde uma perspectiva humana ou desde a perspectiva da sustentabilidade, se tende a um mesmo discurso que possibilita a convergencia e evolucao do conceito de desenvolvimento a uma tendencia muito menos utopica, com maior alcance e aplicacao sob o paradigma cientifico de sustentabilidade em termos de bem-estar humano.

Introduccion. El proposito del presente trabajo es el de investigar la probabilidad de supervivencia de las nuevas empresas creadas en el sector industrial de Medellin entre los anos 2000 y 2010. Asi mismo evidenciar algunos determinantes de los factores de exito en la consolidacion y aceptacion de las empresas en el mercado, en los periodos de tiempo inmediatamente posteriores a su gestacion. Objetivo. Calcular la tasa acumulada de supervivencia de las empresas pertenecientes al sector Industrial de la ciudad de Medellin creadas en el periodo comprendido entre los anos 2000 y 2010. Esto teniendo en cuenta el tamano, naturaleza juridica y sector industrial al que se circunscriben. Materiales y metodos. Para dar cuenta del objetivo se utilizo la funcion de supervivencia en un cierto periodo muestra el porcentaje de empresas vivas despues de que transcurran un numero determinado de periodos tras su aparicion. La funcion de riesgo muestra el porcentaje de empresas que cierra t periodos despues de su nacimiento. A su vez, la funcion de supervivencia recoge el porcentaje de empresas vivas t periodos despues del nacimiento. Resultados. El riesgo de desaparicion de una empresa disminuye conforme aumenta la antiguedad, adicionalmente, es menor en las empresas que nacen con un mayor tamano. La creacion de empresas es mayor entre las de menor tamano, pero presentan mayores tasas de mortalidad en los primeros anos de vida. La supervivencia de las nuevas empresas se encuentra positivamente relacionada con su tamano al nacer.

LANGUAGE NOTE | Document text in English; abstract also in Chinese. The implementation of Physical Education homework (PEHW) is new in Hong Kong. We examined the perception differences between a) parents and students; b) boys and girls towards PEHW in a primary school. Ninety students and 56 parents responded to a questionnaire after the completion of 1-week structured or unstructured compulsory PEHW daily which included aerobic, muscular and flexibility workout. T-test results showed that the students stated significantly lower levels of agreement than their parents regarding enjoyment of doing PEHW and the further organization of different PEHWs in school. No significant perception differences were reported between boys and girls towards the PEHW (p>0.05). Lack of time is the most frequently reason reported by the students and their parents as their intrapersonal barrier to participate in PEHW. Some incentives were suggested to promote the participation of PEHW. The present study suggests implementing PEHW with a reward scheme in Hong Kong. 小學四至六年級的學生完成一週強制性體育家課後，九十名學生和五十六名家長交回問卷回收率分別達94.2%和51.9%。T形檢驗結果顯示家長較學生贊成學校繼續組織及推行不同類型的體育家課。男女學童對體育家課的接受程度和各方面的反應是無明顯分別的。在開放式問題中，時間不足是最對學生參與體育家課的最大個人障礙。最後有多於三分之一的學生完成了餘下三週非強制性的體育家課。提議體育家課與獎勵計劃一起推行。

The integration of the various ideological views by the academic community around the great problems facing the planet has allowed the establishment of a complex system of practical and theoretical relationships between man and nature, generating a strong connection between sustainable development and human development, and conferring greater prominence to the role of human beings, according to their powers, liberties and actions for achieving and maximizing their individual and collective well-being. In this regard, this chapter aims to analyze the influence of the human context in the historical conceptualization of development and its relation with human and planetary well-being over the past 50 years. We try to prove that when it comes to development from the human perspective or from the perspective of sustainability, it tends towards the same discourse that enables convergence and evolution of the concept of development into a much less utopian trend, with greater scope and application under the scientific paradigm of sustainability in terms of human welfare. RESUMEN La integración de varias posturas ideológicas de la comunidad académica en torno a los grandes problemas que afronta el planeta ha permitido establecer un complejo sistema de relaciones prácticas y teóricas entre el hombre y la naturaleza, generando una fuerte conexión entre desarrollo sostenible y desarrollo humano, y confiriendo mayor prominencia al papel de los seres humanos, de acuerdo a sus poderes, libertades, y acciones para alcanzar y maximizar su bienestar individual y colectivo. En este sentido, el propósito de este capítulo es analizar la influencia del contexto humano en la conceptualización histórica del desarrollo y su relación con el bienestar humano y planetario durante los últimos 50 anos. Intentamos comprobar que cuando se trata del desarrollo desde una perspectiva humana o desde la perspectiva de la sostenibilidad, se tiende hacia un mismo discurso que posibilita la convergencia y evolución del concepto de desarrollo hacia una tendencia mucho menos utópica, con mayor alcance y aplicación bajo el paradigma científico de sostenibilidad en términos de bienestar humano. RESUMO A integração de várias posturas ideológicas da comunidade académica em torno aos grandes problemas que afronta o planeta há permitido estabelecer um complexo sistema de relações práticas e teóricas entre o homem e a natureza, gerando uma forte conexão entre desenvolvimento sustentável e desenvolvimento humano, e conferindo maior prominéncia ao papel dos seres humanos, de acordo aos seus poderes, liberdades, e ações para alcançar e maximizar seu bem-estar individual e coletivo. Neste sentido, o propósito deste capítulo é analisar a influência do contexto humano na conceptualização histórica do desenvolvimento e sua relação com o bem-estar humano e planetário durante os últimos 50 anos. Tentamos comprovar que quando se trata do desenvolvimento desde uma perspectiva humana ou desde a perspectiva da sustentabilidade, se tende a um mesmo discurso que possibilita a convergência e evolução do conceito de desenvolvimento a uma tendência muito menos utópica, com maior alcance e aplicação sob o paradigma científico de sustentabilidade em termos de bem-estar humano.

Introduction. The intention of this work is to invetigate the probability of survival of the new companies created in the Medellín Industrial sector between the years 2000 and 2010. Also to highlight some determinants of the factors of success in the consolidation and acceptance of companies in the Market, in the time lapses immediately following their gestation. Objective. Calculate the cumulative survival rate of companies belonging to the Industrial sector of the city of Medellín created in the period between 2000 and 2010. Considering the size, legal nature and industrial sector to which it is circumscribed. Materials and methods. To account for the objective was used the survival function in a certain period shows the percentage of companies alive after a certain number of periods after their appearance. The risk function shows the percentage of companies closing t periods of time after its birth. Results. The risk of disappearance of a company decreases as the antiquity increases, additionally, is smaller in companies that are born with a larger or big size. The creation of companies is greater among the smaller ones, but present higher mortality rates in the first years of life. The survival of new companies is positively related to their size at birth. Resumen Introducción. El propósito del presente trabajo es el de investigar la probabilidad de supervivencia de las nuevas empresas creadas en el sector industrial de Medellín entre los años 2000 y 2010. Así mismo evidenciar algunos determinantes de los factores de éxito en la consolidación y aceptación de las empresas en el mercado, en los periodos de tiempo inmediatamente posteriores a su gestación. Objetivo. Calcular la tasa acumulada de supervivencia de las empresas pertenecientes al sector Industrial de la ciudad de Medellín creadas en el período comprendido entre los años 2000 y 2010. Esto teniendo en cuenta el tamaño, naturaleza jurídica y sector industrial al que se circunscriben. Materiales y métodos. Para dar cuenta del objetivo se utilizó la función de supervivencia en un cierto período muestra el porcentaje de empresas vivas después de que transcurran un número determinado de períodos tras su aparición. La función de riesgo muestra el porcentaje de empresas que cierra t períodos después de su nacimiento. A su vez, la función de supervivencia recoge el porcentaje de empresas vivas t períodos después del nacimiento. Resultados. El riesgo de desaparición de una empresa disminuye conforme aumenta la antigüedad, adicionalmente, es menor en las empresas que nacen con un mayor tamaño. La creación de empresas es mayor entre las de menor tamaño, pero presentan mayores tasas de mortalidad en los primeros años de vida. La supervivencia de las nuevas empresas se encuentra positivamente relacionada con su tamaño al nacer. Resumo Introdução. O propósito do presente trabalho é o de investigar a probabilidade de supervivência das novas empresas criadas no setor industrial de Medellín entre os anos 2000 e 2010. Assim mesmo evidenciar alguns determinantes dos fatores de sucesso na consolidação e aceitação das empresas no mercado, nos períodos de tempo imediatamente posteriores à sua gestação. Objetivo. Calcular a taxa acumulada de supervivência das empresas pertencentes ao sector Industrial da cidade de Medellín criadas no período entre os anos 2000 e 2010. Isto tendo em conta o tamanho, natureza jurídica e setor industrial ao que se circunscrevem. Materiais e métodos. Para dar conta do objetivo se utilizou a função de supervivência num certo período de amostra a porcentagem de empresas vivas depois de que transcorram um número determinado de períodos após sua aparição. A função de risco mostra a porcentagem de empresas que fecha t períodos depois do seu nascimento. Por sua vez, a função de supervivência recolhe a porcentagem de empresas vivas t períodos depois do nascimento. Resultados. O risco de desaparição de uma empresa diminui conforme aumenta a antiguidade, adicionalmente, é menor nas empresas que nascem com um maior tamanho. A criação de empresas é maior entre as de menor tamanho, mas apresentam maiores taxas de mortalidade nos primeiros anos de vida. A supervivência das novas empresas se encontra positivamente relacionada com seu tamanho ao nascer.

LANGUAGE NOTE | Document text in English; abstract also in Chinese. Introduction: The purposes of this study were to examine (a) the relationship between Body Mass Index (BMI) and the perception of body image, (b) the body satisfaction level (BSS), and (c) the most satisfied and dissatisfied body part. Methods: 588 university students (aged: 20.0±2.2 years; BMI: 20.3±2.8 kg/m2) from four universities in Hong Kong indicated their perceived ‘ideal’ and the ‘healthiest’ male and female figure from 9-figure rating scale. Body Image Discrepancy (BID) between their ‘current’ and ‘ideal’ figure was calculated. Results: Men reported significantly higher level of BSS than women. BMI correlated with BSS in women (r=.-263, p

The adeno-associated viruses (AAVs), which are being developed as gene delivery vectors, display differential cell surface glycan binding and subsequent tissue tropisms. For AAV serotype 1 (AAV1), the first viral vector approved as a gene therapy treatment, and its closely related AAV6, sialic acid (SIA) serves as their primary cellular surface receptor. Toward characterizing the SIA binding site(s), the structure of the AAV1-SIA complex was determined by X-ray crystallography to 3.0 Å. Density consistent with SIA was observed in a pocket located at the base of capsid protrusions surrounding icosahedral 3-fold axes. Site-directed mutagenesis substitution of the amino acids forming this pocket with structurally equivalent residues from AAV2, a heparan sulfate binding serotype, followed by cell binding and transduction assays, further mapped the critical residues conferring SIA binding to AAV1 and AAV6. For both viruses five of the six binding pocket residues mutated (N447S, V473D, N500E, T502S, and W503A) abolished SIA binding, whereas S472R increased binding. All six mutations abolished or decreased transduction by at least 50% in AAV1. Surprisingly, the T502S substitution did not affect transduction efficiency of wild-type AAV6. Furthermore, three of the AAV1 SIA binding site mutants—S472R, V473D, and N500E—escaped recognition by the anti-AAV1 capsid antibody ADK1a. These observations demonstrate that common key capsid surface residues dictate both virus binding and entry processes, as well as antigenic reactivity. This study identifies an important functional capsid surface “hot spot” dictating receptor attachment, transduction efficiency, and antigenicity which could prove useful for vector engineering. IMPORTANCE The adeno-associated virus (AAV) vector gene delivery system has shown promise in several clinical trials and an AAV1-based vector has been approved as the first gene therapy treatment. However, limitations still exist with respect to transduction efficiency and the detrimental effects of preexisting host antibodies. This study aimed to identify key capsid regions which can be engineered to overcome these limitations. A sialic glycan receptor recognition pocket was identified in AAV1 and its closely related AAV6, using X-ray crystallography. The site was confirmed by mutagenesis followed by cell binding and transduction assays. Significantly, residues controlling gene expression efficiency, as well as antibody escape variants, were also identified. This study thus provides, at the amino acid level, information for rational structural engineering of AAV vectors with improved therapeutic efficacy.

Adeno-associated viruses (AAVs) are small single-stranded DNA viruses that can package and deliver nongenomic DNA for therapeutic gene delivery. AAV8, a liver-tropic vector, has shown great promise for the treatment of hemophilia A and B. However, as with other AAV vectors, host anti-capsid immune responses are a deterrent to therapeutic success. To characterize the antigenic structure of this vector, cryo-electron microscopy and image reconstruction (cryo-reconstruction) combined with molecular genetics, biochemistry, and in vivo approaches were used to define an antigenic epitope on the AAV8 capsid surface for a neutralizing monoclonal antibody, ADK8. Docking of the crystal structures of AAV8 and a generic Fab into the cryo-reconstruction for the AAV8-ADK8 complex identified a footprint on the prominent protrusions that flank the 3-fold axes of the icosahedrally symmetric capsid. Mutagenesis and cell-binding studies, along with in vitro and in vivo transduction assays, showed that the major ADK8 epitope is formed by an AAV variable region, VRVIII (amino acids 586 to 591 [AAV8 VP1 numbering]), which lies on the surface of the protrusions facing the 3-fold axis. This region plays a role in AAV2 and AAV8 cellular transduction. Coincidently, cell binding and trafficking assays indicate that ADK8 affects a postentry step required for successful virus trafficking to the nucleus, suggesting a probable mechanism of neutralization. This structure-directed strategy for characterizing the antigenic regions of AAVs can thus generate useful information to help re-engineer vectors that escape host neutralization and are hence more efficacious.

Parvoviruses package a ssDNA genome. Both nonpathogenic and pathogenic members exist, including those that cause fetal infections, encompassing the entire spectrum of virus phenotypes. Their small genomes and simple coding strategy has enabled functional annotation of many steps in the infectious life cycle. They assemble a multifunctional capsid responsible for cell recognition and the transport of the packaged genome to the nucleus for replication and progeny virus production. It is also the target of the host immune response. Understanding how the capsid structure relates to the function of parvoviruses provides a platform for recombinant engineering of viral gene delivery vectors for the treatment of clinical diseases, and is fundamental for dissecting the viral determinants of pathogenicity. This review focuses on our current understanding of parvovirus capsid structure and function with respect to the infectious life cycle.

El presente trabajo permite reconocer el modelo de direccion por competencias basicas distintivas (DCBD),como herramienta para que las pymes exportadoras de Medellin puedan medir su competitividad internacional,a partir de los recursos, competencias y capacidades existentes en su estructura administrativa y organizacional.Para ello se disena un modelo de tipo cualitativo no probabilistico que combina escalas de medicion de linkertcon otras de diferencial semantico, cuyo producto es una matriz que permite clasificar la competencia esencialen tres categorias: valiosa, rara y exclusiva. De esta manera, las empresas pueden conocer que tan preparadasse encuentran, en terminos de sus recursos y capacidades, para internacionalizarse. El factor innovador deesta herramienta consiste en adicionar a los modelos de competencias basicas distintivas la orientacion haciala internacionalizacion

The three-dimensional structure of adeno-associated virus (AAV) serotype 6 (AAV6) was determined using cryo-electron microscopy and image reconstruction and using X-ray crystallography to 9.7- and 3.0-Å resolution, respectively. The AAV6 capsid contains a highly conserved, eight-stranded (βB to βI) β-barrel core and large loop regions between the strands which form the capsid surface, as observed in other AAV structures. The loops show conformational variation compared to other AAVs, consistent with previous reports that amino acids in these loop regions are involved in differentiating AAV receptor binding, transduction efficiency, and antigenicity properties. Toward structure-function annotation of AAV6 with respect to its unique dual glycan receptor (heparan sulfate and sialic acid) utilization for cellular recognition, and its enhanced lung epithelial transduction compared to other AAVs, the capsid structure was compared to that of AAV1, which binds sialic acid and differs from AAV6 in only 6 out of 736 amino acids. Five of these residues are located at or close to the icosahedral 3-fold axis of the capsid, thereby identifying this region as imparting important functions, such as receptor attachment and transduction phenotype. Two of the five observed amino acids are located in the capsid interior, suggesting that differential AAV infection properties are also controlled by postentry intracellular events. Density ordered inside the capsid, under the 3-fold axis in a previously reported, conserved AAV DNA binding pocket, was modeled as a nucleotide and a base, further implicating this capsid region in AAV genome recognition and/or stabilization.

Wild-type TP53 exons 5-8 contain CpG dinucleotides that are prone to methylation-dependent mutation during carcinogenesis, but the regulatory effects of methylation affecting these CpG sites are unclear. To clarify this, we first assessed site-specific TP53 CpG methylation in normal and transformed cells. Both DNA damage and cell ageing were associated with site-specific CpG demethylation in exon 5 accompanied by induction of a truncated TP53 isoform regulated by an adjacent intronic promoter (P2). We then synthesized novel synonymous TP53 alleles with divergent CpG content but stable encodement of the wild-type polypeptide. Expression of CpG-enriched TP53 constructs selectively reduced production of the full-length transcript (P1), consistent with a causal relationship between intragenic demethylation and transcription. 450K methylation comparison of normal (TP53-wildtype) and cancerous (TP53-mutant) human cells and tissues revealed focal cancer-associated declines in CpG methylation near the P1 transcription start site, accompanied by rises near the alternate exon 5 start site. These data confirm that site-specific changes of intragenic TP53 CpG methylation are extrinsically inducible, and suggest that human cancer progression is mediated in part by dysregulation of damage-inducible intragenic CpG demethylation that alters TP53 P1/P2 isoform expression. © 2015 The Authors. Molecular Carcinogenesis Published by Wiley Periodicals, Inc.

Biocatalytic CO2sequestration to reduce greenhouse-gas emissions from industrial processes is an active area of research. Carbonic anhydrases (CAs) are attractive enzymes for this process. However, the most active CAs display limited thermal and pH stability, making them less than ideal. As a result, there is an ongoing effort to engineer and/or find a thermostable CA to fulfill these needs. Here, the kinetic and thermal characterization is presented of an α-CA recently discovered in the mesophilic hydrothermal vent-isolate extremophileThiomicrospira crunogenaXCL-2 (TcruCA), which has a significantly higher thermostability compared with human CA II (melting temperature of 71.9°Cversus59.5°C, respectively) but with a tenfold decrease in the catalytic efficiency. The X-ray crystallographic structure of the dimeric TcruCA shows that it has a highly conserved yet compact structure compared with other α-CAs. In addition, TcruCA contains an intramolecular disulfide bond that stabilizes the enzyme. These features are thought to contribute significantly to the thermostability and pH stability of the enzyme and may be exploited to engineer α-CAs for applications in industrial CO2sequestration.

El desarrollo desde la perspectiva económica le ha asignado al crecimiento de la producción y por ende a la utilización intensiva de los factores productivos la responsabilidad de convertirse en el principal indicador de “bienestar social” sin llegar a considerar el progresivo deterioro ambiental y la creciente destrucción de los recursos naturales, en un sistema que a todas luces ha dado resultados pero al mismo tiempo ha manifestado ser enormemente desigual. El presente ensayo constituye un ejercicio que pretende ir más allá de constituir una simple diatriba frente a los límites en los que nos ha embarcado el capitalismo, más bien pretende evidenciar, a través de la recopilación de un variado acervo teórico, una serie de reflexiones sobre la necesidad de replantear los incentivos y la regulación que existe detrás del sistema, con el fin de comprender las necesidades de afinar los modelos de crecimiento que promuevan una transición mucho más equitativa hacia la asignación de responsabilidades frente al deterioro y agotamiento del planeta.

Este trabajo parte de la evidencia sobre las eventuales dificultades en las organizaciones en la disposición de los recursos, capacidades y conocimientos necesarios para emprender de manera adecuada un proceso de internacionalización. Se plantea el diseño de un instrumento apropiado para diagnosticar el nivel de madurez de las capacidades organizacionales de las pequeñas y medianas empresas del municipio de Medellín, tomando como muestra específica, algunas empresas del sector de la tecnología y la innovación. Para tal efecto, se abordan algunos conceptos y modelos asociados a la internacionalización de empresas desde la teoría de recursos y capacidades. De igual forma, se consideran los conceptos de adquisición, integración y asimilación de conocimiento como aspectos que son inherentes a cada una de las capacidades organizacionales de las empresas del sector, y que a partir de la interrelación con el entorno externo e interno muestran como las organizaciones transforman la combinación de recursos en capacidades centrales y ventajas competitivas. 1 Este artículo es producto de los resultados finales del proyecto DIAGNÓSTICO SOBRE LAS CAPACIDADES ORGANIZACIONALES CON FINES DE INTERNACIONALIZACIÓN EN LAS PEQUEÑAS Y MEDIANAS EMPRESAS DEL MUNICIPIO DE MEDELLIN (SECTOR: TECNOLOGÍA E INNOVACIÓN) del Grupo de Investigaciones Económicas GINVECO. Financiado por la Universidad Autó- noma Latinoamericana en la convocatoria 02 de 2012. Recibido el 22 de enero de 2013 y aprobado el 10 de junio de 2013. 2 El docente Robert NG Henao es Economista Industrial (2001), Especialista en Finanzas Corporativas y Mercado de Capitales (2005) de la UPB, Magister en Administración (2010) de la Universidad de Medellín y estudiante del Doctorado en Desarrollo Sostenible de la Universidad de Manizales. Actualmente es el Coordinador General de Posgrados de la Universidad de Medellín y Docente en pregrado y posgrado de la Universidad Autónoma Latinoamericana, de la Escuela de Ingeniería de Antioquia, de la Universidad Tecnológica de Pereira y de la Universidad EAFIT. Su dirección electrónica es robertng@udem.edu.co 3 El docente Julián Santiago Vásquez Roldán es Economista, Especialista en Gerencia Financiera de la Universidad Autónoma Latinoamericana (UNAULA), Especialista en Responsabilidad Social Empresarial de la Universidad de Buenos Aires (UBA), Magister en Desarrollo de la Universidad Pontificia Bolivariana (UPB) y estudiante del Doctorado en Desarrollo Sostenible de la Universidad de Manizales. Actualmente es el Decano de Economía de la Universidad Autónoma Latinoamericana y Docente en pregrado y posgrado de la Universidad de Medellín. Su dirección electrónica es julian.vasquez@ unaula.edu.co This work is based on evidence about the possible difficulties in organizations at managing the resources, skills and knowledge required to properly undertake a process of internationalization. It proposes the design of an appropriate instrument for diagnosing the level of maturity of the organizational capacities of small and medium-sized enterprises of the municipality of Medellin, taking as a specific sample some companies in the sector of technology and innovation. For this purpose, some of the concepts and models associated with the internationalization of companies are discussed. Similarly, the concepts of acquisition, integration and assimilation of knowledge as considered as aspects inherent to each of the organizational capacities of enterprises in the sector, and from the interaction with the external and internal environment show how organizations transform the combination of resources on core competencies and competitive advantages.

Adeno-associated viruses (AAVs) are being development as gene delivery vectors and have shown promise in several clinical trials. And an AAV1-based vector has been approved by the European Commission for the treatment of lipoprotein lipase deficiency disease. However, limitations in tissue transduction specificity as well as neutralization by pre-existing antibodies remain are two major obstacles. To overcome these problems, it is important to characterize functional capsid regions that dictate virus binding to cellular receptors during infection and the potential overlap(s) of these regions with capsid antigenic epitopes. In this study, the sialic acid (SIA) binding site on AAV1 was determined by solving the structure of the AAV1-SIA complex using X-ray crystallography. Residues that form the SIA binding pocket are identical between AAV1 and AAV6; hence, structurally predicted SIA binding sites were mutated on both serotypes to confirm their role in the SIA interaction. Binding and transduction assays with these mutants in CHO cell lines Pro5, Lec2, Lec8, and Lec1, which display different terminal glycans, confirmed the structurally mapped binding pocket. Furthermore, native dot blot showed that several of the AAV1 SIA binding mutants can escape from antibody recognition. This finding is consistent with the overlap between the SIA binding site and the previously mapped AAV1 epitopes. Significantly, a glycan binding mutant with slightly reduced transduction ability is able to escape from antibody recognition. This study identifies an overlap between receptor recognition and antibody reactivity and provides amino acid level information for rational capsid engineering of AAV vectors for improved therapeutic efficacy.

Unlike the well-known effects of promoter methylation, the functional significance of altered intragenic (gene body) CpG methylation remains unclear, particularly in genes such as the TP53 tumor suppressor which lack a 5′ CpG island. Here we show that CpG-specific demethylation of TP53 exon 5 in normal human and mouse cells is inducible by X-irradiation; this is accompanied by co-expression of a 5′-truncated TP53 isoform, raising the possibility that demethylation permits transcription from the known alternative promoter (P2) in intron 4. Consistent with this, in vivo expression of fully pre-methylated TP53 exonic constructs is associated with reduced basal and damage-inducible expression of both full-length and truncated TP53. In contrast, virally TP53-reconstituted Caco-2 and PC-3 human cancer cell lines respond to damage by upregulating expression of full-length TP53 and reducing expression of the truncated RNA isoform; CDKN1A expression varies directly with P2 isoform expression but inversely with the P1 transcript in these cells, suggesting that the isoform mediates downstream transactivation. 450K methylation analysis of adjacent normal and TP53-mutated human pancreatic cancer tissues suggests a mutation-specific decrease of intragenic TP53 methylation in intron 1 near P1 (p < 0.02 ) and a reciprocal increase in intron 4 near P2 (p < 0.01). Archival TP53 database analysis indicates that CpG-specific mutation frequency in human tumors is inversely associated with damage-inducible demethylation at the same sites in vitro (Spearman coefficient -7.1 ), consistent with methylation-dependent downregulation of transcription-coupled repair. We conclude that intragenic alterations of TP53 methylation are both physiologically inducible and functional, and hypothesise that tumor progression is drivable by either (i) intragenic hypermethylation affecting P1 as a field defect in TP53-wt tumor or adjacent normal tissues, or (ii) damage-inducible repression of P2 isoform expression associated with defective intron 4 demethylation, together with overexpression of full-length p53, in TP53-mutant tumors and cells. Citation Format: James Blackburn, Robert Ng, Daniel Roden, Jianmin Wu, Richard J. Epstein. Damage-inducible intragenic demethylation activates transcription of an alternative intronic promoter in TP53-wildtype but not mutant human cells and tumors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-85. doi:10.1158/1538-7445.AM2014-LB-85