Enhancing the magnetic response on polycrystalline nanoframes through mechanical deformation.

The mechanical and magnetic properties of polycrystalline nanoframes were investigated using atomistic molecular dynamics and micromagnetic simulations. The magneto-mechanical response of Fe hollow-like nanocubes was addressed by uniaxial compression carried out by nanoindentation. Our results show that the deformation of a nanoframe is dominated at lower strains by the compression of the nanostructure due to filament bending. This leads to the nanoframe twisting perpendicular to the indentation direction for larger indentation depths. Bending and twisting reduce stress concentration and, at the same time, increase coercivity. This unexpected increase of the coercivity occurs because the mechanical deformation changes the cubic shape of the nanoframe, which in turn drives the system to more stable magnetic states. A coercivity increase of almost 100 mT is found for strains close to 0.03, which are within the elastic regime of the Fe nanoframe. Coercivity then decreases at larger strains. However, in all cases, the coercivity is higher than for the undeformed nanoframe. These results can help in the design of new magnetic devices where mechanical deformation can be used as a primary tool to tailor the magnetic response on nanoscale solids.

Nanoparticle Shape Influence over Poly(lactic acid) Barrier Properties by Molecular Dynamics Simulations.

Climate change is leading us to search for new materials that allow a more sustainable environmental situation in the long term. Poly(lactic acid) (PLA) has been proposed as a substitute for traditional plastics due to its high biodegradability. Various components have been added to improve their mechanical, thermal, and barrier properties. The modification of the PLA barrier properties by introducing nanoparticles with different shapes is an important aspect to control the molecular diffusion of oxygen and other gas compounds. In this work, we have described changes in oxygen diffusion by introducing nanoparticles of different shapes through molecular dynamics simulations. Our model illustrates that the existence of curved surfaces and the deposition of PLA around them by short chains generate small holes where oxygen accumulates, forming clusters and reducing their mobility. From the several considered shapes, the sphere is the most suitable structure to improve the barrier properties of the PLA.

The Escape from Malnutrition of Chilean Boys and Girls: Height-for-Age Z Scores in Late XIX and XX Centuries.

We studied the trends of height-for-age (HAZ) Z scores by socioeconomic status (SES) groups of Chilean boys and girls aged 5-18 born between 1877 and 2001, by performing a meta-analysis of 53 studies reporting height-for-age sample data from which 1258 HAZ score datapoints were calculated using the 2000 reference growth charts for the US of the Centers for Disease Control and Prevention (CDC). We found stagnant mean and median HAZ scores of about -1.55 to -1.75 for the general population, and -2.2 to -2.55 for lower SES groups up to cohorts born in the 1940s. However, we found an upwards structural change in cohorts born after the 1940s, a period in which HAZ scores grew at a pace of about 0.25 to 0.30 HAZ per decade. Since this change happened in a context of moderate Gross Domestic Product (GDP) growth, high and persistent income inequality, and stagnant wages of the working class, we discuss the extent to which our findings are associated with the increase in public social spending and the implementation and expansion of a variety of social policies since the 1940s and early 1950s.

Use of Phycobiliproteins from Atacama Cyanobacteria as Food Colorants in a Dairy Beverage Prototype.

The interest of the food industry in replacing artificial dyes with natural pigments has grown recently. Cyanobacterial phycobiliproteins (PBPs), phycoerythrin (PE) and phycocyanin (PC), are colored water-soluble proteins that are used as natural pigments. Additionally, red PE and blue PC have antioxidant capabilities. We have formulated a new food prototype based on PBP-fortified skim milk. PBPs from Andean cyanobacteria were purified by ammonium sulfate precipitation, ion-exchange chromatography, and freeze-drying. The stability of PE and PC was evaluated by changes in their absorption spectra at various pH (1-14) and temperature (0-80 °C) values. Purified PBPs showed chemical stability under pH values of 5 to 8 and at temperatures between 0 and 50 °C. The antioxidant property of PBP was confirmed by ABTS (2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical ion scavenging, and FRAP (Ferric Antioxidant Power) assays. The absence of PBP toxicity against Caenorhabditis elegans was confirmed up to 1 mg PBP/mL. Skim milk fortified with PE obtained a higher score after sensory tests. Thus, a functional food based on skim milk-containing cyanobacterial PBPs can be considered an innovative beverage for the food industry. PBPs were stable at an ultra-high temperature (138 °C and 4 s). PBP stability improvements by changes at its primary structure and the incorporation of freeze-dried PBPs into sachets should be considered as alternatives for their future commercialization.

Who Differentiates by Skin Color? Status Attributions and Skin Pigmentation in Chile.

A growing body of research has shown that phenotypes and skin pigmentation play a fundamental role in stratification dynamics in Latin American countries. However, the relevance of skin color on status attribution for different status groups has been little studied in the region. This article seeks to broaden the research on phenotypic status cues using Chile as a context for analysis - a Latin American country with a narrow although continuous spectrum of skin tones, marked status differences, and a mostly white elite. We draw on status construction theory to hypothesize that skin pigmentation in Chile has become a status cue, although its heuristic relevance could differ across status groups. Using visual stimuli and a repeated measure design, we studied this relationship and tested whether the use of skin pigmentation as a status cue is conditional upon the status of those categorizing others. The results reveal that participants attribute, on average, lower status to others of darker skin. Besides, skin pigmentation has a conditional effect on the social status of participants: whereas skin pigmentation does not work as a status cue for lower status participants, it is an important status marker for the categorizations that middle and especially higher status participants perform. The phenotypic composition of reference groups of low- and high-status individuals and system justification are discussed as potential explanations for these results.

Alendronato administrado en el foco de fractura: Estudio experimental en conejos / Alendronate administered at the fracture site. Experimental study in rabbits

Introducción: El objetivo de este estudio experimental fue evaluar el resultado radiológico e histológico del empleo de alendronato colocado localmente en el foco de fracturas de fémur en conejos. Materiales y Métodos: Se utilizaron 30 conejos a los cuales se les fracturó el fémur derecho y se los dividió en tres grupos de 10 animales cada uno. A los conejos del grupo 1 se les colocó una solución con alendronato en el foco de fractura; los del grupo 2 fueron sometidos al mismo procedimiento a los siete días de la fractura y el grupo 3 era de control. Se realizó la evaluación radiográfica en el momento de la fractura y a los 42 días del procedimiento. Se evaluaron las características del callo óseo mediante anatomía patológica, radiología y tomografía computarizada. Resultados: Se evaluaron 24 conejos (2 conejos del grupo 2 y 4 del grupo 3 murieron). El análisis histológico reveló moderada formación ósea en los tres grupos, sin diferencias estadísticamente significativas (p = 0,8336). Según los resultados de los estudios por imágenes, no existieron diferencias estadísticamente significativas en el tamaño del callo óseo entre los grupos para los dos estudios (radiografía: p = 0,777 y tomografía: p = 0,349). Conclusión: El alendronato colocado localmente en el foco de fractura, en la etapa aguda y luego de una semana, no alteró, de manera estadísticamente significativa, el proceso normal de consolidación, determinado por anatomía patológica y radiología, a las seis semanas de la fractura de fémur en conejos. Nivel de Evidencia: II

Introduction: The aim of this experimental study was to evaluate the radiologic and histological results of the use of alendronate administered locally at the fractures site in rabbits. Methods: The fractured right femur of 30 rabbits was used for evaluation. The animals were distributed in three groups of 10 rabbits each. A solution with alendronate was placed at the fracture site in group 1; the same procedure was performed 7 days after the fracture in group 2, and group 3 functioned as control. Radiographic evaluation was performed at the time of the fracture and at day 42. Radiological, PA and CT-scan evaluations of bone callus characteristics in each rabbit were performed. Results: Twenty-four rabbits were evaluated (2 rabbits in group 2 and 4 in group 3 died). Histological evaluation evidenced moderate bone formation in the three groups without statistically significant differences (p=0.8336). Concerning imaging studies, there were no statistically significant differences in the size of bone callus among groups for both studies (X-rays: p=0.777 and CT: p=0.349). Conclusion: The use of alendronate administered locally at the fracture site, in the acute period and after one week, did not alter the normal consolidation process determined by PA and radiology, six weeks after femur fracture in rabbits. Level of Evidence: II

Revisión femoral con tallo cónico de fijación distal / Femoral revision surgery with conical stem of distal fixation

Introducción: La pérdida de hueso proximal en la cirugía de revisión del vástago femoral es el principal desafío que enfrenta el cirujano al efectuar una revisión. El objetivo es obtener una fijación estable de los componentes, así como la restauración de la cinemática de la articulación. Materiales y Métodos: Evaluamos a 37 pacientes (39 revisiones femorales), entre 2010 y 2014, a quienes se les colocaron tallos cónicos no cementados de fijación distal (28 modulares y 11 no modulares). La edad promedio fue 63.5 años. Se incluyó a 18 (48,64%) mujeres y 19 (51,35%) hombres. Se intervinieron 14 (35,89%) casos de aflojamiento aséptico, 14 (35,89%) infecciones, 7 (17,94%) fracturas periprotésicas, 3 (7,69%) fracturas de vástago y una (2,56%) por inestabilidad. El seguimiento medio fue de 42 meses (rango 24-74). Resultados: El puntaje medio de Harris mejoró de 37 (rango 10-77) antes de la operación a 81 (rango 33-96) en el último seguimiento. Cuatro pacientes (10,2%) presentaron luxación, uno (2,5%) tuvo una infección profunda; otro (2,5%), una fractura intraoperatoria; en tres (7,6%) pacientes, se produjo un hundimiento y fue necesario revisar 2 (5,1%) implantes femorales. Conclusiones: Con el vástago cónico se han logrado resultados satisfactorios en 2-6 años de seguimiento, en varias condiciones de revisión femoral. Requiere de una técnica simple y reproducible, con una mejoría clínica ampliamente publicada. Nivel de Evidencia: IV

Introduction: Proximal bone loss at the femoral stem is the main challenge facing surgeons at the time of revision total hip arthroplasty. The aim of revision surgeries is to obtain a stable placement of components and to restore joint kinematics. Methods: Between 2010 and 2014, we evaluated 37 patients (39 hips) in whom non-cemented femoral stems were used (28 modular and 11 non-modular).The average age was 63.5 years. Study patients included 18 (48.64%) women and 19 (51.35%) men. Causes of reoperation included 14 (35.89%) cases of aseptic loosening, 14 (35.89%) infections, 7 (17.94%) periprosthetic fractures, 3 (7.69%) stem fractures and one (2.56%) for instability. Mean follow-up was 42 months (range 24-74). Results: The average Harris score improved from 37 (range 10-77) points before surgery to 81 points (range 33-96) at the last follow-up. Four patients (10.2%) presented dislocation, one (2.5%) suffered a deep infection, one (2.5%) had an intra-operative fracture; 3 (7.6%) patients presented subsidence and it was necessary to revise 2 (5.1%) femoral implants. Conclusions: Satisfactory results were obtained with the femoral stem in 2 to 6 years of follow-up in several conditions of femoral revision surgeries. It requires a simple and reproducible technique with clinical improvement that has been widely published in the literature. Level of Evidence: IV

Colgajos pediculados en defectos de tejidos blandos en niños / Pedicled flaps for coverage of soft-tissue defects in children

Introducción: El objetivo de este trabajo es evaluar los resultados obtenidos con la utilización de colgajos pediculados en la cobertura de defectos de tejidos blandos, en los miembros, en niños. Materiales y Métodos: Se evaluaron 13 niños que sufrieron pérdida o retracción grave de tejidos blandos, y requirieron de un colgajo pediculado para la adecuada cobertura del defecto, entre 2004 y 2013. La edad promedio fue de 7.9 años. El tiempo entre el trauma inicial y la realización del colgajo promedió 39 días. La cobertura se efectuó con colgajo sural (4 casos), colgajo en isla vasculonervioso (2 casos), colgajo radial (2 casos), colgajo inguinal (3 casos), colgajo abdominal (1 caso) y colgajo dorsal ancho (1 caso). En todos los pacientes, la reparación o la reconstrucción de las lesiones asociadas se llevaron a cabo en el mismo tiempo quirúrgico. Resultados: El seguimiento promedio fue de19 meses. En los 13 casos se obtuvo una buena cobertura del defecto. El tiempo de internación fue, en promedio, de 8.1 días. Hubo una infección, una necrosis superficial y dos pacientes con cicatriz hipertrófica. Dos pacientes necesitaron tenólisis y dos, zetaplastias. Conclusiones: Los colgajos pediculados permiten obtener una adecuada cobertura en la mayoría de estas lesiones en niños; la reconstrucción de las lesiones asociadas por debajo de ellos es posible sin inconvenientes. Algunas desventajas de estos colgajos en adultos son la inmovilización del miembro afectado, con una potencial rigidez y la formación de edema, pero esto no se observó en los niños.

Introduction: The aim of this study is to evaluate the results achieved using pedicle flaps for coverage of soft-tissue defects in children. Methods: Thirteen children who suffered trauma or burns of the extremities, with soft-tissue loss or severe retraction, requiring a pedicled flap for adequate coverage, treated between 2004 and 2013, were evaluated. Average age 7.9 years. Time between initial trauma and flap coverage averaged 39 days. Coverage was achieved using a sural flap (4 cases), a neurovascular island flap (2 cases), a radial forearm flap (2 cases), a groin flap (3 cases), an abdominal flap (1 case), and a latissimus dorsi flap (1 case). Associated lesions were repaired or reconstructed at the same surgical procedure in all patients. Results: Follow-up averaged 19 months. Adequate coverage was achieved in all 13 cases. Hospitalization time averaged 8.1 days. One patient developed infection, one flap had superficial necrosis and two patients developed hypertrophic scars. Two patients needed extensor tendon tenolisis and two requiredz-plasties. Conclusions: Pedicled flaps allow for an adequate coverage in most soft-tissues defects in children; it is possible to simultaneously reconstruct all associated injuries. The main disadvantage of these flaps in adults is immobilization of the affected limb, with potential stiffness and edema formation, butthis was not evident in the children included in this series.

Trends in physical stature across socioeconomic groups of Chilean boys, 1880-1997.

This paper studies the trends in height-by-age across socioeconomic groups of Chilean boys aged 5-18 born between 1880 and 1997, by performing a meta-analysis of 38 studies reporting height-by-age published since 1898. We estimate the trends using quantile regressions and by analyzing detailed height data from five selected studies. Both methods yield an average decennial increase in height of 1-1.1cm, and 0.9 and 1.2-1.3 cm for boys of upper and lower socioeconomic status (SES), respectively. SES differences in heights of 9-11 cm are observed up to the late 1940s. However, boys born after the 1930s exhibit substantial convergence in height between socioeconomic groups, driven by an increase in height of middle and lower SES boys of 1.5 and 1.4-2 cm per decade, respectively. As a result, SES differences in height decreased to 5 cm in 1990s. Since these changes occurred in a context of moderate economic growth and persistent income inequality, we argue that our findings are associated with the emergence and expansion of social policies in Chile since the 1940s, which delivered steady improvements in health, nutrition and living conditions.

Colgajo fasciocutáneo sural inverso para cobertura de defectos de partes blandas en pierna, tobillo y pie / Reverse fasciocutaneous sural flap for soft-tissue coverage in leg, ankle and foot

Introducción: El objetivo de este trabajo es evaluar los resultados obtenidos con la utilización del colgajo fasciocutáneo sural de base distal para la reconstrucción de defectos de partes blandas alrededor de la tibia distal, el tobillo y el pie. Materiales y Métodos: Se evaluaron, en forma retrospectiva, 20 colgajos pediculados fasciocutáneos surales inversos realizados entre 2007 y 2013. la edad promedio de los pacientes era de 42 años (rango 6-79); 14 hombres y 5 mujeres. las causas de los defectos fueron: postraumáticas (17 casos, un caso bilateral) y secundarias a resecciones oncológicas (2 casos). la muestra incluyó tres pacientes diabéticos, una mujer obesa y ocho pacientes tabaquistas. en 10 casos, las heridas presentaban exposición tendinosa y, en 10 casos, exposición ósea. el diámetro promedio de los defectos fue de 8,9 x 5,75 cm. Resultados: El seguimiento promedio fue de 16 meses. se logró una exitosa cobertura completa del defecto en los 20 casos. el tiempo promedio de internación fue de 3.15 días. tres colgajos presentaron necrosis parcial superficial, en un caso el colgajo sufrió necrosis en su tercio distal y, en un paciente, se decidió amputar la extremidad por persistencia de la osteomielitis. Conclusiones: Pese a que se han descrito múltiples opciones de cobertura en defectos de tejidos blandos alrededor de la tibia distal, el tobillo y el pie, el colgajo sural inverso es, en la actualidad, uno de los procedimientos más frecuentes para cubrir estos defectos. se evaluaron 20 colgajos surales inversos y se logró la cobertura completa de los defectos de tejidos blandos, tanto en defectos postraumáticos como en los resultantes de resecciones oncológicas.

Background: The objective of this paper is to evaluate the results after the use of distally-based reverse fasciocutaneous sural flap in the reconstruction of soft-tissue loss around the distal tibia, ankle and foot. Methods: Twenty fasciocutaneous pedicled reverse sural flaps performed between 2007 and 2013 were retrospectively evaluated. Average age of the patients: 42 years (range 6-79), 14 were male and 5 were female. soft-tissue loss was post-traumatic in 17 cases (one bilateral) and secondary to oncologic resections in two cases. the series included three diabetic patients, one obese woman, and eight smokers. ten cases had exposed tendons and ten had bony exposure. defect size averaged 8.9 x 5.75 cm. Results: Follow-up averaged 16 months. complete soft tissue defect coverage was achieved in all 20 cases. Hospital stay averaged 3.15 days. three flaps had superficial necrosis, one flap suffered necrosis of its distal third, and the lower extremity was amputated in a patient due to persistent osteomyelitis. Conclusions: Although multiple coverage options have been described for soft-tissue coverage around the distal tibia, ankle and foot, the reverse sural flap is one of the most frequently used procedures to cover these defects. We evaluated 20 reverse sural flaps, achieving complete soft-tissue coverage in post-traumatic lesions as well as in those defects resulting from oncologic resections.

Study of the in vivo role of Mce2R, the transcriptional regulator of mce2 operon in Mycobacterium tuberculosis.

BACKGROUND: Tuberculosis is one of the leading causes of mortality throughout the world. Mycobacterium tuberculosis, the agent of human tuberculosis, has developed strategies involving proteins and other compounds called virulence factors to subvert human host defences and damage and invade the human host. Among these virulence-related proteins are the Mce proteins, which are encoded in the mce1, mce2, mce3 and mce4 operons of M. tuberculosis. The expression of the mce2 operon is negatively regulated by the Mce2R transcriptional repressor. Here we evaluated the role of Mce2R during the infection of M. tuberculosis in mice and macrophages and defined the genes whose expression is in vitro regulated by this transcriptional repressor. RESULTS: We used a specialized transduction method for generating a mce2R mutant of M. tuberculosis H37Rv. Although we found equivalent replication of the MtΔmce2R mutant and the wild type strains in mouse lungs, overexpression of Mce2R in the complemented strain (MtΔmce2RComp) significantly impaired its replication. During in vitro infection of macrophages, we observed a significantly increased association of the late endosomal marker LAMP-2 to MtΔmce2RComp-containing phagosomes as compared to MtΔmce2R and the wild type strains. Whole transcriptional analysis showed that Mce2R regulates mainly the expression of the mce2 operon, in the in vitro conditions studied. CONCLUSIONS: The findings of the current study indicate that Mce2R weakly represses the in vivo expression of the mce2 operon in the studied conditions and argue for a role of the proteins encoded in Mce2R regulon in the arrest of phagosome maturation induced by M. tuberculosis.

Percepciones sobre el estudio de casos, como estrategia de aprendizaje, en estudiantes de enfermería / Perceptions about the case study, as learning strategy in nursing students

La presente investigación de enfoque cualitativo, basada en la compilación de información mediante la observación en el aula y sistematizada a través de algunos métodos e instrumentos derivados de la teoría fundamentada, tuvo como objeto analizar las percepciones de estudiantes de Enfermería sobre el 'estudio de casos', estrategia de aprendizaje utilizada por la carrera, en la Universidad del Mar. A partir de la información reunida se elaboraron categorías interpretativas, con el fin de comprender y explicar el valor pedagógico del proceso didáctico en estudio. Los sujetos investigados corresponden a un grupo de estudiantes de segundo año de la carrera, con quienes, uno de los docentes investigadores, trabajó la estrategia de aprendizaje, 'estudio de casos'. La información fue obtenida a través de: la observación participante, las entrevistas semiestructuradas, el grupo de discusión y la revisión de documentos. De los resultados obtenidos emergieron las siguientes 'categorías': aprendizaje, trabajo en equipo, mediación docente y formación profesional. Como conclusiones, los estudiantes revelaron que, mediante el 'estudio de casos', experimentaron un proceso fundamental en su formación profesional: fortalecer el trabajo en equipo y desarrollar cualidades para liderar un grupo. También haber desarrollado importantes cambios en la forma de aprender, transformándose en protagonistas activos que toman sus propias decisiones y que construyen aprendizajes significativos en la aplicación de situaciones reales, perfilando un rol profesional sólido que le permitirá un buen desempeño en la solución de problemas de su quehacer profesional.

The purpose of this research with a qualitative approach, based on information compiled during classroom observation and systematized through some methods and tools derived from grounded theory, was to analyze the perceptions of nursing students about the 'case study' learning strategy used by the nursing career, at the Universidad del Mar. In order to understand and explain the pedagogical value of the didactic process in study, interpretative categories were elaborated from the gathered information. The investigated subjects are a group of nursing students in their second year, with whom, one of the academic researcher, worked out the learning strategy. The information was gathered through: participant observation, structured interviews, group discussions and document review. From the reached results, the following 'categories' emerged: learning, teamwork, tutorial mediation and vocational training. Conclusion, the students revealed that, through 'case study', they experienced a fundamental process in their professional training: strengthening teamwork and developing skills to lead a group. They also recognize important changes in the way of learning, becoming active students making their own decisions and who construct significant learning in the application of real situations, outlining a strong professional role that will allow a good performance in solving their professional problems at work.

Male facial anthropometry and attractiveness.

The symmetry and masculinity of the face are often considered important elements of male facial attractiveness. However, facial preferences are rarely studied on natural faces. We studied the effect of these traits and facial metric parameters on facial attractiveness in Spanish and Colombian raters. In total, 13 metric and 11 asymmetry parameters from natural, unmanipulated frontal face photographs of 50 Spanish men were measured with the USIA semiautomatic anthropometric software. All raters (women and men) were asked to rank these images as potential long-term partners for females. In both sexes, facial attractiveness was negatively associated with facial masculinity, and preference was not associated with facial symmetry. In Spanish raters, both sexes preferred male traits that were larger in the right side of the face, which may reflect a human tendency to prefer a certain degree of facial asymmetry. We did not find such preference in Colombian raters, but they did show stronger preference for facial femininity than Spanish raters. Present results suggest that facial relative femininity, which is expected to signal, eg good parenting and cooperation skills, may be an important signal of mate quality when females seek long-term partners. Facial symmetry appears unimportant in such long-term mating preferences.

Cementum protein 1 (CEMP1) induces differentiation by human periodontal ligament cells under three-dimensional culture conditions.

PDL (periodontal ligament) is a source of multi-potent stem cells in humans and their differentiation potential to a cementoblast and osteoblast phenotypes has been shown. Tissue construction from PDL-derived cells could be considered as a valuable technique for periodontal regenerative medicine. On these basis, we determined the role of CEMP1 (cementum protein 1) as a factor to induce differentiation of human PDL cells in a 3D (three-dimensional) fashion. Human PDL cells were grown in an RCCS (rotary cell culture system) D-410 RWV (rotating wall vessel) bioreactor, and maintained in either experimental (CEMP1 2.5 µg/ml) or control media during 4 weeks. Cell proliferation in the presence of CEMP1 was determined. The tissue-like structure formed was analysed histologically, stained with Alizarin Red and Alcian Blue. ALP (alkaline phosphatase)-specific activity, immunostaining, RT-PCR (reverse transcription-PCR) and Western blotting were performed to determine the expression of BSP (bone sialoprotein), enamel [AMBN (ameloblastin) and AMEL (amelogenin)], cementum [CAP (cementum attachment protein) and CEMP1] and cartilage-related proteins (Sox9, aggrecan, types II and X collagens). Our results show that hrCEMP1 (human recombinant CEMP1) promoted cell proliferation by human PDL cells in 3D cultures and induced the formation of a tissue-like structure resembling bone and/or cementum and material similar to cartilage. The addition of hrCEMP1 to the 3D human PDL cell cultures increased ALP-specific activity by 2.0-fold and induced the expression of markers for the osteogenic, cementogenic and chondrogenic phenotypes at the mRNA and protein levels. Our data show that human PDL cells in 3D cultures with the addition of CEMP1 has the potential to be used for the bioengineering reconstruction of periodontal tissues and cartilage since our results suggest that CEMP1 stimulates human PDL cells to differentiate towards different phenotypes.

Incidencia de enfermedades crónicas y factores de riesgo de la comunidad en la Isla Floreana, Provincia de Galápagos / Incidence of chronic diseases and risks factors of the community in the Floreana Island, Province of Galápagos

Tipo de estudio: retrospectivo, analítico, descriptivo. Objetivo: conocer cuales son las enfermedades crónicas y recurrentes más frecuentes, las enfermedades odontológicas de la infancia, el control prenatal y los factores de riesgo de la comunidad presentes en la isla Floreana, utilizando las fichas familiares del Ministerio de Salud Pública, pero modificadas. Resultados: encontramos un total de 97 personas que habitan en la isla, agrupados en 33 familias, de entre los cuales hay una embarazada sin ningún control prenatal, alta incidencia de caries en los niños; las enfermedades respiratorias agudas predominan en los menores de 15 años y las gastrointestinales en los mayores de 15 años; se encontraron 3 niños con esquema de vacunación incompleto y un buen sistema de eliminación de la basura. Conclusiones: se encontró que a pesar de tener riesgos higiénicos sanitarios altos, la mayoría de las enfermedades no son causadas por éstos; son producto del medio ambiente, malos hábitos alimenticios o a causa del tipo de trabajo. Mientras que las enfermedades crónicas de mayor riesgo como hipertensión arterial, diabetes y cáncer son mejor controladas.

Type of study: retrospective, analytic, descriptive. Objective: to know which are the chronic disease and recurrents more frequently, odontologic diseases of the childhood, prenatal control and the risk factors of the community who live in the Floreana Island, using the families’ card of the Department of Public Health but modificated. Results: we found a total of 97 persons that live in the island, in groups of 33 families, between them, there is a pregnant without a prenatal control, high incidence of tooth decay in children; the acute respiratory diseases predominate in younger of 15 years and gastrointestinal in older of 15 years; we found 3 children with a incomplete vaccinations and a good garbage elimination control. Conclusions: in spite of have high risk of health hygienic, the most of the diseases is not caused by this; there are produce by environment, bad food habit or jobs causes. Whereas chronic diseases of high risk like hypertension, diabetes, and cancer, there are more under control

Blood flow is required for rapid endothelial cell damage induced by a snake venom hemorrhagic metalloproteinase.

The effects of blood flow interruption on the ultrastructural alterations induced by a snake venom hemorrhagic metalloproteinase on skeletal muscle capillary endothelial cells were studied. Saline solution or the metalloproteinase BaP1, from the venom of Bothrops asper, was injected into the gastrocnemius muscles of mice with normal blood flow perfusion or with blood supply abrogated by two different protocols. Tissue was collected 5 min after injection, and both histological and ultrastructural analyses of the muscle capillary vessels were performed. Muscle with normal perfusion injected with saline solution had the typical morphology of normal capillaries, whereas injection of metalloproteinase to muscle with normal blood flow induced prominent degenerative changes in endothelial cells, such as reduction in cell thickness, decrease in the amount of pinocytotic vesicles, prominent distention and rupture leading to extravasation. In contrast, endothelial cells of capillaries from tissue devoid of blood flow and injected with the metalloproteinase did not show degenerative changes. The only alterations observed were a reduction in the capillary lumen and the presence of cytoplasmic projections, or 'pseudopods', both of which were also present in capillaries from tissue devoid of blood flow and injected with saline solution, thus suggesting that such changes are due to the drop in transmural pressure as a consequence of blood flow interruption. Our observations support the hypothesis that biophysical forces operating in the microvasculature, i.e., transmural pressure-dependent wall tension and shear stress, play a significant role in the pathogenesis of endothelial cell damage and hemorrhage induced by snake venom metalloproteinases.

Pulmonary hemorrhage induced by jararhagin, a metalloproteinase from Bothrops jararaca snake venom.

Jararhagin is the most important hemorrhagic component in the venom of the snake Bothrops jararaca, a species of medical importance in South America. It is a P-III zinc-dependent metalloproteinase comprising catalytic, disintegrin-like, and cysteine-rich domains. Jararhagin injected intravenously into mice induced rapid and prominent bleeding in the lungs, whereas other organs were devoid of overt hemorrhagic manifestations. This action depends on the proteolytic activity of jararhagin, since it was abrogated by the synthetic inhibitor batimastat. There were conspicuous ultrastructural alterations in cells at the alveolo-capillary unit, i.e., capillary endothelial cells and type I pneumocytes, with a characteristic pattern of "regional alveolar damage" associated with extravasation. These pathological effects were observed under conditions in which the whole blood clotting time, bleeding time, and fibrinogen levels were not affected. 125I-labeled jararhagin is concentrated mainly in liver and kidneys after iv injection, with little radioactivity observed in the lungs, thereby indicating that the predominance of pulmonary microvascular damage is not due to a preferential concentration of this enzyme in the lungs. Despite the fact that jararhagin is complexed by plasma proteins after iv injection, its hemorrhagic activity was not inhibited by the plasma proteinase inhibitor alpha(2)-macroglobulin, and was only partially reduced by normal mouse serum, suggesting that resistance to inhibition may contribute to its ability to cause pulmonary hemorrhage.

Bioeticas actuales: convergencias y divergencias / Present bioethics

Se presenta una breve paronámica de las diversas corrientes en Bioética que están más en boga, y se discute cuál va a ser el criterio para seguir un camino que sea propositivo: todo depende de si se afirma o niega el acceso al ser y a la trascendencia. Urge rehumanizar la medicina: a los médicos y pacientes. Aceptar los retos ideológicos que se presentan. Aceptar el bien, ligado a la verdad y ambos a la libertad o quedarse en el concepto de lo útil, que deja paso a la autonomía absoluta, al relativismo o nihilismo moral. Después de presentar el paronama, el autor termina haciendo unos cuestionamientos finales, para elegir el camino que se va a seguir, porque la Bioética se encuentra en una encrucijada de voces muy distantes entre sí y, por ello, es importante aclarar el punto de partida y el fin que se busca. En todo momento, el autor tiene como punto de partida una Bioética personalista con base ontológica, apoyada, por lo tanto, en un realismo moderado.