Extracellular cysteine in connexins: Role as redox sensors

Indexación: Scopus.Connexin-based channels comprise hemichannels and gap junction channels. The opening of hemichannels allow for the flux of ions and molecules from the extracellular space into the cell and vice versa. Similarly, the opening of gap junction channels permits the diffusional exchange of ions and molecules between the cytoplasm and contacting cells. The controlled opening of hemichannels has been associated with several physiological cellular processes; thereby unregulated hemichannel activity may induce loss of cellular homeostasis and cell death. Hemichannel activity can be regulated through several mechanisms, such as phosphorylation, divalent cations and changes in membrane potential. Additionally, it was recently postulated that redox molecules could modify hemichannels properties in vitro. However, the molecular mechanism by which redox molecules interact with hemichannels is poorly understood. In this work, we discuss the current knowledge on connexin redox regulation and we propose the hypothesis that extracellular cysteines could be important for sensing changes in redox potential. Future studies on this topic will offer new insight into hemichannel function, thereby expanding the understanding of the contribution of hemichannels to disease progression.http://journal.frontiersin.org/article/10.3389/fphys.2016.00001/ful

Obtaining and Structural Characterization of M-type Hexaferrites Doped with Two Cations in the Fe3+ Sites

A study of the microstructural and structural properties of M-type barium hexaferrites (BaM) samples doped with two dopants in the Fe3+ sites: (Co3+, Al3+), (Co2+, Ti4+) and (Co2+, Sn4+) is reported. The samples were obtained using the conventional ceramic method. The structure was investigated by using of X-ray diffraction (XRD) to determine the dopant distribution in the Fe3+ sites

Effects of successive judo matches on interlimb asymmetry and bilateral deficit

Objective: To verify the effects of successive judo matches on interlimb asymmetry and bilateral deficit in judo athletes. Design: Repeated measures Setting: University Judo center Participants: Fourteen male judo athletes Outcome measures: Four simulated matches consisting of 4-min. Before the first match and after each match athletes were submitted to single leg tests – Countermovement Jump (SLCMJ) and Standing Long Jump (SLSLJ), and handgrip strength (HGS) in the dominant and non-dominant limbs. Interlimb asymmetry was calculated in both jumps and handgrip strength tests. Results: Most jump-derived variables did not change the magnitude of asymmetry throughout the matches (p>0.05), with the exception of jump height asymmetry in SLCMJ, that increased after the second match (p=0.001). The HGS decreased in both hands from the first match (p<0.001), without asymmetry. The highest bilateral strength deficit was observed in post-match 1 and post-match 2 (close to 10%). Conclusion: Four-successive judo matches did not change the magnitude of interlimb asymmetry, with exception of SLCMJ height, which increased after the second match. The handgrip strength decreased throughout the matches, but similarly in both hands. Finally, the direction of asymmetry showed consistency throughout the matches only for SLCMJ height

Dialectical Interrelation Between: Problematic Situation, Real Problem, Scientific Problem, Object and Field, in the Investigation Design: A Necessary Reflection

All research responds to the need of solutions to a problem that directly or indirectly affects society. The development of the same largely certifies and determines the constant search for solutions. The main objective of the present study was to arrive at a clear conceptualization, as complete as possible, of some the most important terms that come up during an investigation design: Problematic Situation, Real Problem, Scientific Problem, and Object and Field, given the visible shortcomings observed in pre- and post-graduate theses when the research work is being developed and defended. The methodology consisted of basically developing a reflection around these terms (the vision that different authors have in this regard was very helpful), as well as the presentation of varied examples contributed to see the meaning of these important concepts more clearly. The study shows in a scientifically grounded way the achievement of the above. The way in which the presentation of the different concepts was handled removes any possibility of mistakes. Keywords: methodology scientific investigation, problem, object, field. Resumen Toda investigación parte del apremio en dar una respuesta a la solución de un problema que afecta de una manera directa o indirecta a la Sociedad. En gran medida, el propio desarrollo de la misma compulsa y determina esa constante búsqueda de soluciones. El objetivo principal del presente estudio fue llegar a una conceptualización clara, y lo más acabada posible, de algunos de los más importantes términos que se manejan durante el diseño de una investigación: Situación Problémica, Problema Real, Problema Científico, Objeto y Campo, dada las visibles falencias que se observan en tesistas de pre y postgrado a la hora de desarrollar y defender sus trabajos de investigación. La metodología consistió, básicamente, en desarrollar una reflexión en torno a estos términos; para lo cual resultó de gran ayuda la visión que tienen diferentes autores al respecto; así como, la exposición de variados ejemplos contribuyó a ver más definidamente el significado de estos importantes conceptos. El estudio muestra de forma científicamente fundamentada el logro de lo anterior. La forma en que se maneja la presentación de los diferentes conceptos aleja toda posibilidad de equívocos. Palabras clave: metodología investigación científica, problema, objeto, campo

Head movement and its relation to hearing

Head position at any point in time plays a fundamental role in shaping the auditory information that reaches a listener, information that continuously changes as the head moves and reorients to different listening situations. The connection between hearing science and the kinesthetics of head movement has gained interest due to technological advances that have increased the feasibility of providing behavioral and biological feedback to assistive listening devices that can interpret movement patterns that reflect listening intent. Increasing evidence also shows that the negative impact of hearing deficits on mobility, gait, and balance may be mitigated by prosthetic hearing device intervention. Better understanding of the relationships between head movement, full body kinetics, and hearing health, should lead to improved signal processing strategies across a range of assistive and augmented hearing devices. The purpose of this review is to introduce the wider hearing community to the kinesiology of head movement and to place it in the context of hearing and communication with the goal of expanding the field of ecologically-specific listener behavior

Shortening the lipid A acyl chains of Bordetella pertussis enables depletion of lipopolysaccharide endotoxic activity

Whooping cough, or pertussis, is an acute respiratory infectious disease caused by the Gram-negative bacterium Bordetella pertussis. Whole-cell vaccines, which were introduced in the fifties of the previous century and proved to be effective, showed considerable reactogenicity and were replaced by subunit vaccines around the turn of the century. However, there is a considerable increase in the number of cases in industrialized countries. A possible strategy to improve vaccine-induced protection is the development of new, non-toxic, whole-cell pertussis vaccines. The reactogenicity of whole-cell pertussis vaccines is, to a large extent, derived from the lipid A moiety of the lipopolysaccharides (LPS) of the bacteria. Here, we engineered B. pertussis strains with altered lipid A structures by expressing genes for the acyltransferases LpxA, LpxD, and LpxL from other bacteria resulting in altered acyl-chain length at various positions. Whole cells and extracted LPS from the strains with shorter acyl chains showed reduced or no activation of the human Toll-like receptor 4 in HEK-Blue reporter cells, whilst a longer acyl chain increased activation. Pyrogenicity studies in rabbits confirmed the in vitro assays. These findings pave the way for the development of a new generation of whole-cell pertussis vaccines with acceptable side effects

Penile Cancer in Cali, Colombia: 10 Years of Casuistry in a Tertiary Referral Center of a Middle-Income Country

Background: Penile cancer is a rare disease in Colombia; in Cali, it represents 0.7% of all cancers. Penile cancer has been associated with old age, bad hygiene, smoking and lack of circumcision. This study aimed to describe the sociodemographic and clinica&nbsp; characteristics of patients with penile cancer who consulted to a tertiary referral hospital. Methods: A case series of all penile cance cases at a reference institution in Cali during 2001-2010. Socioeconomic, demographic and clinical features of patients were described, and bivariate analyses were carried out. Results: There were 46 penile cancer cases. The average age was 60 ± 16.9 years. The main reason for consultation was an exophytic mass on the penis (75.0%). The most common location was the glans (69.6%), and the more frequent histology type was the squamous cell carcinoma (95.7%). With regard to risk factors, 65.5% of the patients had history of smoking and90.9% did not have circumcision. Patients who underwent radical amputation had higher rates of positive nodes (55% vs. 13.5%, p=0.015) and ulcerative lesions (77.8% vs. 29.7%, p=0.018) than those who did not have the procedure done. Recurrence was associated with the presence of lymphadenopathy (p=0.02) and history of circumcision (p=0.015). Conclusion: Most of the patients with penile cancer found in this study had old age, history of tobacco use and lack of circumcision. Patients who presented with lymph node metastasis had to undergo more radical procedures and suffered a greater rate of recurrence compared with those without lymph node involvement. Robust ..

Biotransformation of a tetrahydrofuran lignan by the endophytic fungus Phomopsis Sp.

The biotrasformation of the tetrahydrofuran lignan, (-)-grandisin, by the endophitic fungus Phomopsis sp, obtained from Viguiera arenaria, led to the formation of a new compound determined as 3,4-dimethyl-2-(4'-hydroxy-3',5'-dimethoxyphenyl)-5-methoxy-tetrahydrofuran. The metabolite was evaluated against the parasite Trypanosoma cruzi, the causative agent of Chagas's disease, and showed a trypanocidal activity (IC50 9.8 &#956;mol L-1) similar to the natural precursor (IC50 3.7 &#956;mol L-1).A biotransformação da lignana tetraidrofurânica, (-)-grandisina, pelo fungo endofítico Phomopsis sp, obtido de Viguiera arenaria, conduziu à formação de um novo metabólito caracterizado como 3,4-dimetil-2-(4'-hidróxi-3',5'-dimetóxifenil)-5-metóxi-tetraidrofurano. O metabólito foi analisado contra o parasita Trypanosoma cruzi, o agente causador da doença de Chagas, e mostrou uma atividade tripanocida (IC50 9,8 &#956;mol L-1) similar ao precursor natural (IC50 3,7 &#956;mol L-1).Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Propuesta de un modelo de administración estratégica desde un enfoque de calidad mediante los lineamientos para la acreditación de programas de pregrado del CNA para el mejoramiento de los procesos del programa de ingeniería industrial de la Universidad del Magdalena

El objetivo general de la investigación es Proponer un modelo de administración estratégica que permita mejorar el programa de ingeniería industrial de la Universidad del Magdalena desde un enfoque de calidad mediante Los Lineamientos de Acreditación de Programas de Pregrado dados por el CNA. El programa de Ingeniería Industrial de la Universidad del Magdalena desde su creación en el año 2000 se ha presentado como una opción para responder a los requerimientos del Departamento; si bien es cierto que ha venido creciendo con el tiempo y consolidándose en el contexto regional, también lo es que existen muchos aspectos por mejorar. Con la finalidad de proponer un modelo de Administración Estratégica para el Programa de Ingeniería Industrial de la universidad del Magdalena que permita su mejoramiento de acuerdo a sus propias necesidades, y teniendo en cuenta las variables que ha definido el Ministerio de Educación a través del CNA en los lineamientos expuestos para la acreditación de Programas de Pregrado en el territorio Nacional se ha desarrollado este proyecto a lo largo de 2 años. Este trabajo de investigación pretende proponer estrategias para el mejoramiento del programa desde la visión de la comunidad universitaria, en especial de los estudiantes, teniendo en cuenta factores tanto internos como externos