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Imagen de apoyo de  Approximal caries: Prevalence and progression rate in Young Danish adults and an innovative non-operative approach for lesions around the EDJ

Approximal caries: Prevalence and progression rate in Young Danish adults and an innovative non-operative approach for lesions around the EDJ

Por: Stefania Martignon | Fecha: 01/01/2005

A literature review disclosed that even under very strict caries preventive control, in young Swedish people many initial approximal lesions slowly progress. A study was performed to investigate if the same trend could be seen in young Danish adults. In 1996 a group of Danish military conscripts were investigated clinically and radiographically. Based on the radiographs, one lesion with radiolucency up to one third in the dentine was randomly selected from each conscript.Contact was established with these former conscripts in 2002 and radiographs taken around 2002 were used to investigate the state of the selected lesions in terms of regression, stabilization or progression. It was observed that about 60% of the selected lesions had progressed during the 5 to 6 year period. Therefore there was a need to look for other preventive measures than those traditionally used in a Danish context, such as instructions in flossing and local application of fluoride. Looking through the literature, it was realized that sealing of occlusal lesions was highly effective but this procedure was not used on approximal surfaces.The next step was to investigate if it was technically possible to seal approximal lesions and if so what material should be used. A laboratory study was conducted in which 6 dental materials were compared in relation to: their handling, presence at the surface of the lesion, and ability to penetrate into a lesion. Based on that study Gluma One Bond® (Heraeus Kulzer) was selected to be used in further studies. The final step was an 18-month clinical investigation to evaluate the effect of sealing approximal lesions. About 80 young adults from Denmark and Colombia participated in this investigation; each had at least 2 initial approximal lesions.One lesion was selected for sealing; the other one acted as control. Baseline radiographs were taken by means of special equipment so new radiographs could be taken in the same position after 18 months. The sealing procedure was performed in accordance with the guideline designed in the laboratory study. The patient was instructed to floss all sealed and non-sealed approximal lesions. Radiographs were used to assess caries progression in the test and control lesions in three ways: by comparing baseline with final scoring of the lesions on the individual conventional radiographs, by reading the conventional radiographs as pairs and finally using subtraction radiography of digitized images.The examiner was blind to lesion type (test or control) for all comparisons and also blind to whether radiographs were baseline or follow up in the case of examinations of the single radiographs and paired comparison. Repeat assessment of the radiographs was conducted on 20% of the radiographs and the subtraction images. For the paired comparison of radiographs and subtraction radiography assessment significantly more control lesions progressed (47.2%; 85%) than test lesions (22.2%; 43%) (P-values<0.05). For the independent examination of the radiographs a similar pattern was seen but the difference between the two groups was not statistically significant (P=0.06).In conclusion, many approximal lesions seemed to progress on young adults irrespective of the preventive regime they were advised to take. This study has developed and investigated a technique for sealing early approximal lesions which seems to be more effective at preventing lesion progression than conventional interventions such as brushing and flossing. There is a need however, for defining more precisely criteria at selecting lesions to be sealed; for developing better materials in terms of better penetration skill and that they stay there, and for clinical investigations which evaluate the long term effect of sealing the approximal lesions.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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Approximal caries: Prevalence and progression rate in Young Danish adults and an innovative non-operative approach for lesions around the EDJ

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Aproximaciones a la medicina tradicional china

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Atoxil: observaciones sobre su valor terapéutico en la sífilis

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Imagen de apoyo de  Attitudes towards body size and physical appearance among Colombian and American college students:A Multi-cultural Study = Actitudes hacia el tamaño del cuerpo y apariencia fisica en estudiantes universitarios Colombianos y Americanos: Un Estudio Multi-C

Attitudes towards body size and physical appearance among Colombian and American college students:A Multi-cultural Study = Actitudes hacia el tamaño del cuerpo y apariencia fisica en estudiantes universitarios Colombianos y Americanos: Un Estudio Multi-C

Por: Natalia Rojas Segura | Fecha: 01/01/2009

The current study analyzed attitudes towards size and physical appearance among four hundred and seventy Colombian and two hundred and ten American college students. The effects of gender and culture (and their interaction) on thin ideal internalization, sociocultural pressure to be thin, and body image dissatisfaction were examined in the sample. Results from the study showed that there are differences between gender and country: Colombian students perceived themselves as having a better body image overall compared to American students; females from both countries had a lower body image satisfaction compared to males. Surprisingly, males from both countries worry about their physical size and appearance. Implications for future research include validating instruments especially for a Colombian population, as well as continuing to include males in studies related to body image and eating disorders because it was found that they were also unsatisfied with their overall body image. 
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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Attitudes towards body size and physical appearance among Colombian and American college students:A Multi-cultural Study = Actitudes hacia el tamaño del cuerpo y apariencia fisica en estudiantes universitarios Colombianos y Americanos: Un Estudio Multi-C

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Imagen de apoyo de  Auricular reconstruction with a nanocomposite polymer = Reconstrucción auricular con un nanopolimero

Auricular reconstruction with a nanocomposite polymer = Reconstrucción auricular con un nanopolimero

Por: Carlos Enrique Ramírez Blanco | Fecha: 01/01/2012

Auricular reconstruction remains one of the biggest challenges faced by plastic surgeons. Reconstruction with autologous cartilage has proven to offer a lasting reconstruction with acceptable cosmetic results when performed by very experienced surgeons; however, the learning curve is long and few surgeons around the world have mastered this technique. For less experienced surgeons clinical outcome is frequently wanting; moreover, reconstructions with autologous cartilage carry its own burden of donor site morbidity and surgical complications. In order to reduce operating time, avoid the risks and complications inherent of cartilage harvest and homogenize clinical outcome of ear reconstruction, auricular off the shelf scaffolds have been manufactured using biomaterial.The only auricular scaffold present in the market today is made of high density porous polyethylene and commercialized under the trade name Medpor®. Despite its limited success porous polyethylene has not fully convinced surgeons due to its stiffness and extrusion rates. A novel nanocomposite polymer has been developed by Prof. Seifalian and its team at UCL by the incorporation of polyhedral oligomeric silsesquioxane (POSS) nanocage as pendant side chains into poly (carbonate-urea) urethane. POSS PCU can be shaped as an auricle, it mimics the elastic properties of auricular native cartilage and supports cell growth and proliferation. In this project we have used human dermal fibroblasts primary cells (HFF) to study and compare cellular response on POSS PCU and Medpor®.In vitro experiments detected significantly higher cell adhesion on POSS PCU when compared to Medpor® (p < 0,05). Dynamic condition at 50 RMP was found reduce cell attachment on both polymers; under this condition POSS PCU supports higher cell adhesion than Medpor®. Even though no difference on cell proliferation or metabolic activity per cell was found between the two polymers, POSS PCU, with higher cell adhesion, have higher overall cell proliferation and metabolic activity. Collagen production per cell was found to be significantly increased on Medpor®; however, the higher cell number found on POSS PCU managed to produce as much total collagen as its counterpart. Even though POSS PCU is non-degradable, HFF were found to lower POSS PCU young’s modulus and make the scaffolds more flexible. Even though further refinement of POSS PCU scaffold production and the need for additional in vitro and in vivo studies, this biomaterial is a promising alternative for auricular reconstruction.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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Auricular reconstruction with a nanocomposite polymer = Reconstrucción auricular con un nanopolimero

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Imagen de apoyo de  Autopercepción de la imagen corporal y conductas alimentarias de riesgo en estudiantes universitarios de medicina en Xalapa, Veracruz, México (2014)

Autopercepción de la imagen corporal y conductas alimentarias de riesgo en estudiantes universitarios de medicina en Xalapa, Veracruz, México (2014)

Por: Guadalupe Jacqueline Olalde Libreros | Fecha: 08/02/2019

Introducción: el estándar de belleza actual se asocia con la delgadez, situación que puede alterar la percepción corporal y consecuentemente conducir al desarrollo de algún trastorno alimentario. Objetivo: determinar la relación de los índices de insatisfacción y distorsión de la imagen corporal y las conductas alimentarias de riesgo (CAR), en una población universitaria de estudiantes de medicina en Veracruz, México. Materiales y métodos: estudio transversal analítico en una población de 187 estudiantes. Se elaboró una cédula que incluyó el SFS-test para evaluar la imagen corporal y estimar los índices de insatisfacción y distorsión de la imagen corporal; el Cuestionario Breve de Conductas Alimentarias de Riesgo validado en población mexicana, así como variables sociales. Se realizó análisis descriptivo con medidas básicas de frecuencia y dispersión, bivariado y multimodal. Resultados: el 43 % eran mujeres y la edad promedio 21 años (±1.7) similar en ambos sexos. La prevalencia de alto riesgo de car fue de 8.6%, superior en los hombres (9.4% frente a 7.4%) y del mediano riesgo 23.5% con la distribución invertida por sexo (28.4 % en las mujeres y 19.8 % en los hombres). El índice de insatisfacción fue del 59.4 %, quienes percibieron tener mayor peso del que les gustaría tener y en la distorsión de la imagen corporal se observó que un 41.2 % suponía tener mayor peso que el arrojado por la evaluación antro- pométrica. Conclusión: los índices de insatisfacción mostraron gradiente de correlación positivo con las CAR, siendo más evidente en los hombres.
Fuente: Universidad del Rosario - Revista Ciencias de la Salud Tipo de contenido: Artículos
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Autopercepción de la imagen corporal y conductas alimentarias de riesgo en estudiantes universitarios de medicina en Xalapa, Veracruz, México (2014)

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Imagen de apoyo de  Autophagy Proteins ATG5 and ATG7 Are Essential for the Maintenance of Human CD34(+) Hematopoietic Stem-Progenitor Cells

Autophagy Proteins ATG5 and ATG7 Are Essential for the Maintenance of Human CD34(+) Hematopoietic Stem-Progenitor Cells

Por: María Catalina; Folkerts Gómez Puerto | Fecha: 01/01/2016

Abstract:Autophagy is a highly regulated catabolic process that involves sequestration and lysosomal degradation of cytosolic components such as damaged organelles and misfolded proteins. While autophagy can be considered to be a general cellular housekeeping process, it has become clear that it may also play cell type-dependent functional roles.In this study, we analyzed the functional importance of autophagy in human hematopoietic stem/progenitor cells (HSPCs), and how this is regulated during differentiation. Western blot-based analysis of LC3-II and p62 levels, as well as flow cytometry-based autophagic vesicle quantification, demonstrated that umbilical cord blood-derived CD34(+) /CD38(-) immature hematopoietic progenitors show a higher autophagic flux than CD34(+) /CD38(+) progenitors and more differentiated myeloid and erythroid cells.This high autophagic flux was critical for maintaining stem and progenitor function since knockdown of autophagy genes ATG5 or ATG7 resulted in reduced HSPC frequencies in vitro as well as in vivo. The reduction in HSPCs was not due to impaired differentiation, but at least in part due to reduced cell cycle progression and increased apoptosis.This is accompanied by increased expression of p53, proapoptotic genes BAX and PUMA, and the cell cycle inhibitor p21, as well as increased levels of cleaved caspase-3 and reactive oxygen species. Taken together, our data demonstrate that autophagy is an important regulatory mechanism for human HSCs and their progeny, reducing cellular stress and promoting survival.Resumen: La autofagia es un proceso lisosomal catabólico altamente regulado que implica el secuestro y degradación de componentes citosólicos: tales como proteínas mal plegadas y orgánelos deteriorados. Mientras que la autofagia puede ser considerada como un proceso general de limpieza celular, también juega un papel funcional dependiendo del tipo de célula.En el presente estudio, hemos analizado la importancia de la autofagia en las células madre hematopoyéticas y sus progenitores y cómo dicho proceso está regulado durante la diferenciación. El análisis de los niveles de LC3-II y p62, así como la cuantificación de la autofagia mediante citometría de flujo demostraron que los progenitores hematopoyéticos inmaduros CD34 (+) / CD38 (-) tienen un flujo de autofagia mayor que las células eritroides y mieloides. Este alto flujo de autofagia es crucial para las células madre y los progenitores hematopoyéticos inmaduros CD34 (+) / CD38 (-) ya que la disminución en los niveles de ATG7 y ATG5 resulta en una reducción de dichas células tanto in vitro como in vivo.Lo anterior es consecuencia de la inhibición parcial del ciclo celular y de un aumento en apoptosis. Adicionalmente, observamos un incremento en la expresión de p53, los genes pro-apoptosis BAX y PUMA, el inhibidor de ciclo celular p21, los niveles de caspasa-3 clivada y las especies reactivas del oxígeno.En conclusión, nuestros datos demuestran que la autofagia es un mecanismo de regulación importante para las células madre hematopoyéticas y sus progenitores reduciendo los niveles de estrés y promoviendo su supervivencia.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Artículos
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Autophagy Proteins ATG5 and ATG7 Are Essential for the Maintenance of Human CD34(+) Hematopoietic Stem-Progenitor Cells

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Ayudemos al aprovechamiento de los alimentos en el organismo.

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Imagen de apoyo de  Beneficencia pública: 30 de Septiembre de 1881

Beneficencia pública: 30 de Septiembre de 1881

Por: Manuel Plata Azuero | Fecha: 01/01/1881

Documento que el presidente de la Junta de beneficencia de Bogotá, Manuel Samper, envía a los miembros de la Asamblea legislativa de Cundinamarca, con el fin de señalar las dificultades que tiene la Junta para poder desarrollar proyectos que mejoren la calidad de servicio y salud del Hospital de la Caridad. El documento se redacta en nombre de varios miembros de la junta, quienes consideran que no se les advirtió sobre las problemáticas existentes antes de que aceptaran se parte del grupo de beneficencia.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Prensa
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Beneficencia pública: 30 de Septiembre de 1881

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Imagen de apoyo de  Bibliografía médica y sensacionalismo. El caso de los Discursos medicinales de Juan Méndez Nieto

Bibliografía médica y sensacionalismo. El caso de los Discursos medicinales de Juan Méndez Nieto

Por: Elena del Río Parra | Fecha: 16/03/2015

Este artículo analiza los Discursos medicinales de Juan Méndez Nieto (ca. 1531-1616) como inconsistentes dentro del corpus bibliográfico médico del siglo XVI. Su retórica y temática los aproxima a la charlatanería, más que a un tratado científico de carácter terapéutico o especulativo. Los Discursos se acercan más a la pseudoautobiografía y a los pliegos sensacionalistas que al grupo de textos sobre remedios americanos.
Fuente: Icanh - Fronteras de la Historia Tipo de contenido: Artículos
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Bibliografía médica y sensacionalismo. El caso de los Discursos medicinales de Juan Méndez Nieto

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