Human prostate epithelial cells and prostate-derived stem cells malignantly transformed in vitro with sodium arsenite show impaired Toll like receptor -3 (TLR3)-associated anti-tumor pathway.

A therapeutic strategy for prostate cancer (PCa) involves the use of 9-cis-retinoic acid (9cRA) to induce cancer stem cells (CSCs) differentiation and apoptosis. Polyinosinic:polycytidylic acid (PIC) is a Toll-like receptor 3 (TLR3) agonist that induces tumor cells apoptosis after activation. PIC+9cRA combination activates retinoic acid receptor ß (RARß) re-expression, leading to CSC differentiation and growth arrest. Since inorganic arsenic (iAs) targets prostatic stem cells (SCs), we hypothesized that arsenic-transformed SCs (As-CSCs) show an impaired TLR3-associated anti-tumor pathway and, therefore, are unresponsive to PIC activation. We evaluated TLR3-mediated activation of anti-tumor pathway based in RARß expression, on As-CSC and iAs-transformed epithelial cells (CAsE-PE). As-CSCs and CAsE-PE showed lower TLR3 and RARß basal expression compared to their respective isogenic controls WPE-Stem and RWPE-1. Also, iAs transformants showed reduced expression of mediators in TLR3 pathway. Importantly, As-CSCs were irresponsive to PIC+9cRA in terms of increased RARß and decreased SC-markers expression, while CAsE-PE, a heterogeneous cell line having a small SC population, were partially responsive. These observations indicate that iAs can impair TLR3 expression and anti-tumor pathway activated by PIC+9cRA in SCs and prostatic epithelial cells. These findings suggest that TLR3-activation based therapy may be an ineffective therapeutic alternative for iAs-associated PCa.

Novel Fabrication Technique for Root-supported Overdentures: A Case Report / Técnica de fabricación novedosa para sobredentaduras apoyadas en la raíz: un reporte de caso

ABSTRACT Tooth and bone preservation is essential to support dentures, especially for elderly patients. Retaining the existing teeth and roots for an overdenture postpones edentulism, and this is a convenient alternative to complete dentures and extraction of teeth. Root-supported overdentures attach to the roots with precision attachments. The fit of the attachment of both the denture and the roots or implants is very important for overdentures. The combination of the attachments increases the retention and stability of attachment-retained overdentures. This technique describes an alternative procedure to fabricate root-supported overdentures with combined locator and casted telescopic attachments.

RESUMEN La preservación de los dientes y los huesos es esencial para apoyar las dentaduras postizas, especialmente para pacientes de edad avanzada. Retener los dientes y raíces existentes para una sobredentadura aplaza el edentulismo, y constituye una alternativa conveniente para completar las dentaduras postizas y la extracción de dientes. Las sobredentaduras apoyadas en la raíz se unen a las raíces con aditamentos de precisión. El ajuste del aditamento tanto de la dentadura como de las raíces o implantes es muy importante para las sobredentaduras. La combinación de los aditamentos aumenta la retención y la estabilidad de las sobredentaduras retenidas por aditamento. Esta técnica describe un procedimiento alternativo para fabricar sobredentaduras ancladas en la raíz con un localizador combinado y aditamentos telescópicos fundidos.

Evaluation of Mechanical Properties of Various Nanofibre Reinforced Bis-GMA/TEGDMA Based Dental Composite Resins / Evaluación de las propiedades mecánicas de varias resinas compuestas dentales basadas en Bis-GMA/TEGDMA reforzadas con nanofibras

ABSTRACT Objective: To investigate the mechanical properties of various mass fractions of Nylon 6 (N6), polymethyl-metacrylate (PMMA) and polyvinylidene-difluoride (PVDF) nanofibres reinforced bisphenol A-glycidyl methacrylate (Bis-GMA) and tri-ethylene glycol dimethacrylate (TEGDMA) based dental composite resins and to evaluate the penetration characteristics of the nanofibres into the resin. Methods: Nylon 6, PMMA and PVDF nanofibres were produced using the electrospinning method. The morphologies of the fabricated nanofibres were evaluated with a scanning electron microscope (SEM). The nanofibres were placed into the resin matrix at different mass fractions (3%, 5% and 7%). The three-point bending test was applied to nanofibre-reinforced dental composite resins and neat resin specimens. The flexural strength (Fs), flexural modulus (EY) and work of fracture (WOF) of the groups were found. The analysis of variance was used for the statistical analysis of the acquired data. Tukey 's multiple test was performed to compare the Fs, EY and WOF means. Fractured surfaces of the samples were observed by SEM, and fracture morphologies were evaluated. Results: Polymethyl-metacrylate nanofibres dissolved in the matrix, and a polymer alloy took place in the matrix. Fibre pull-out and fibre bridging mechanisms were observed by SEM images of the N6 and PVDF nanofibre-reinforced dental composites. The produced nanofibres enhanced the mechanical properties of the dental composite resins. Conclusion: Fibre pull-out and fibre bridging mechanisms on the fractured surfaces of samples may play a key role in the reinforcement of dental composite resins. However, polymer alloy of PMMA nanofibres increased the mechanical properties of the resin matrix.

RESUMEN Objetivo: Investigar las propiedades mecánicas de resinas compuestas dentales basadas en bisfenol A-diglicidildimetacrilato (Bis-GMA) y dimetacrilato trietilen-glicol (TEGDMA) reforzadas con nanofibras de fracciones de masa de Nylon 6 (N6), polimetilmetacrilato (PMMA) y fluoruro de polivinilideno (PVDF), y evaluar las características de la penetración de las nanofibras en la resina. Métodos: Se produjeron nanofibras de Nylon 6, PMMA y PVDF utilizando el método de electrohilado (electrospinning). Las morfologías de las nanofibras fabricadas fueron evaluadas con un microscopio electrónico de barrido (MEB). Las nanofibras fueron introducidas en la matriz de resina en diferentes fracciones de masa (3%, 5% y 7%). La prueba de flexión de tres puntos fue aplicada a las resinas compuestas dentales reforzadas por nanofibras y a las muestras de resina pura. La resistencia a la flexión (Rf), el módulo de flexión (EY) y el trabajo de fractura (WOF) de los grupos fueron halladas. El análisis de varianza se usó para el análisis estadístico de los datos adquiridos. Se realizó la prueba de comparaciones múltiples de Tukey con el propósito de comparar las medidas de Rf, EY y WOF. Las superficies fracturadas de las muestras fueron observadas mediante un MEB, y se evaluaron las morfologías de fractura. Resultados: Las nanofibras de polimetilmetacrilato se disolvieron en la matriz, y tuvo lugar una aleación de polímeros en la matriz. Los mecanismos de desprendimiento de fibras y puenteo de fibras fueron observados mediante imágenes de MEB de los compuestos dentales reforzados con nanofibras de N6 y PVDF. Las nanofibras producidas realzaron las propiedades mecánicas de las resinas compuestas dentales. Conclusión: Los mecanismos de desprendimiento de fibras y puenteo de fibras en las superficies fracturadas de las muestras pueden desempeñar un papel clave en el reforzamiento de las resinas de los compuestos dentales. Sin embargo, la aleación polimérica de las nanofibras de PMMA aumentó las propiedades mecánicas de la matriz de resina.

Seeing to the distant mountain: diagnosis in Tibetan medicine.

To make use of an ancient traditional medical system, we must first comprehend the singular concepts and language that system uses to understand and describe health and illness. The diagnostic procedure is the method by which a person's medical condition is interpreted into the conceptual framework and language of medical science. This article provides a description of traditional Tibetan medical diagnosis and explains how a Tibetan physician perceives and analyzes a presenting illness. It discusses the spiritual, psychological, and physical aspects of the Tibetan medical approach to diagnosis. Addressing these issues can help us to understand what is unique about this system of alternative medicine and how it can inform other models of medical practice.