PPARß/δ and PPARγ maintain undifferentiated phenotypes of mouse adult neural precursor cells from the subventricular zone.

The subventricular zone (SVZ) is one of the main niches of neural stem cells in the adult mammalian brain. Stem and precursor cells in this region are the source for neurogenesis and oligodendrogesis, mainly in the olfactory bulb and corpus callosum, respectively. The identification of the molecular components regulating the decision of these cells to differentiate or maintain an undifferentiated state is important in order to understand the modulation of neurogenic processes in physiological and pathological conditions. PPARs are a group of transcription factors, activated by lipid ligands, with important functions in cellular differentiation and proliferation in several tissues. In this work, we demonstrate that mouse adult neural precursor cells (NPCs), in situ and in vitro, express PPARß/δ and PPARγ. Pharmacological activation of both PPARs isoforms induces proliferation and maintenance of the undifferentiated phenotype. Congruently, inhibition of PPARß/δ and PPARγ results in a decrease of proliferation and loss of the undifferentiated phenotype. Interestingly, PPARγ regulates the level of EGFR in adult NPCs, concurrent with it is function described in embryonic NPCs. Furthermore, we describe for the first time that PPARß/δ regulates SOX2 level in adult NPCs, probably through a direct transcriptional regulation, as we identified two putative PPAR response elements in the promoter region of Sox2. EGFR and SOX2 are key players in neural stem/precursor cells self-renewal. Finally, rosiglitazone, a PPARγ ligand, increases PPARß/δ level, suggesting a possible cooperation between these two PPARs in the control of cell fate behavior. Our work contributes to the understanding of the molecular mechanisms associated to neural cell fate decision and places PPARß/δ and PPARγ as interesting new targets of modulation of mammalian brain homeostasis.

Expresión diferencial de genes asociados a carcinoma de próstata / Differential expression of genes associated with prostate carcinoma

Objetivo: La introducción del Antígeno Prostático Específico (APE) como herramienta de uso masivo en la detección precoz de cáncer prostático (CaP), parece ser al menos parcialmente responsable de la disminución en la mortalidad observada en el último tiempo. Sin embargo, el APE tiene una baja especificidad como marcador de cáncer, especialmente en el rango de 4 a 10 ng/ml donde existe una alta sobreposición con otras patologías de mayor prevalencia como por ejemplo, Hiperplasia Prostática Benigna (HPB). Es por esto, que existe una búsqueda constante de nuevos marcadores. Nuestro objetivo fue caracterizar el perfil de expresión génica del CaP utilizando microarray. Material y métodos: Doce casos de CaP con PSA <10 ng/ml y 4 casos con PSA >10 ng/ml fueron seleccionados prospectivamente para análisis de microarray para 96 genes característicos de tejido prostático. Los análisis se efectuaron por el método de Hierarchical Clustering y se realizó Transcripción Reversa y Reacción de Polimerasa en Cadena para confirmar la información obtenida mediante microarray. Además, se evaluó la presencia en sangre periférica de los genes sobre-expresados en tejido y que pudieran ser marcadores sistémicos de CaP. Resultados: Se definieron 13 genes basándose en su alta expresión, los cuales se agruparon en NCOA4/NDRG1, LDHA/LIM/GSTP1 y KLK2/KLK4 y estos con CALR y CSTB. Los genes SPARCL1, KLK3(PSA), ARSDR1 y ACPP se ordenaron en ramas independientes. El gen ACPP (fosfatasa ácida prostática) fue el más independientemente sobreexpresado. Realizamos RT-PCR para ACPP en 15 tumores primarios y sangre periférica observando señal positiva en 10 (71 por ciento) de 14 casos analizados. Conclusiones: Nuestros resultados indican que el gen ACPP se encuentra sobreexpresado a nivel molecular en tumor primario y sangre periférica, convirtiéndolo en un potencial marcador de CaP con niveles de PSA <10 ng/ml.

Objective: The introduction of prostate specific antigen (PSA) as a screening tool for early detection of prostate cancer (CaP), seems to take a role in being responsible for the decreasing of mortality observed in the last time. Nevertheless, the APE has a low specificity like cancer marker, especially in the rank from 4 to 10 ng/ml where a high superposition with other pathologies of greater prevalence like Benign Prostate Hiperplasia (HPB) exists. This is why there is a constant research for new markers. Our objective was to characterize the gene expression profile of prostate using microarray. Material and Methods: Twelve cases of CaP with PSA <10 ng/ml and 4 cases with PSA >10 ng/ml were prospectively selected for microarray analysis for 96 genes characteristic of prostate tissue. The analysis was performed by the method of Hierarchical Clustering and performed reverse transcription polymerase chain reaction to confirm the information obtained by microarray. We assessed the presence in peripheral blood of over-expressed genes in tissue that could become in systemic markers of PC. Results: We identified 13 genes based on their high expression, which were grouped into NCOA4/NDRG1, LDHA/LIM/GSTP1 and KLK2/KLK4 and those with CALR and CSTB. Genes SPARCL1, KLK3 (PSA) and ACPP ARSDR1 were ordered in separate branches. The ACPP gene (prostatic acid phosphatase) was overexpressed more independently. We RT-PCR for ACPP in 15 primary tumors and peripheral blood positive signal observed in 10 (71per cent) of 14 cases analyzed. Conclusions: Our results indicate that the ACPP gene is overexpressed in a molecular level in primary tumor and peripheral blood, making it a potential marker for prostate cancer with PSA levels <10 ng/ml.

Restauraciones cerámicas: cómo cementarlas? / Ceramic restorations: how to cement them?

En la actualidad ningún material odontológico de uso indirecto sufrió mayor evolución que las cerámicas. El aumento del contenido cristalino mejoró sus propiedades mecánicas, aumentando las opciones de sus indicaciones clínicas. Por lo tanto, esas alteraciones en la composición llevaron a una diferenciación de los procedimientos para la cementación. Anteriormente, la cementacion adhesiva era obligatoria para todas las cerámicas, lo que actualmente ya no es una verdad absoluta. De esta manera, el objetivo de este trabajo de revisión de literatura es establecer el protocolo más indicado para la cementación de las diversas categorías de sistemas cerámicos, teniendo como base las características estructurales de cada material, dando los subsídios para elegir el correcto tratamiento de superficie, agente cementante y sistema adhesivo.

At the present time no dental material for indirect restorations developed more than ceramics. The augmented crystalline content improved their mechanical properties increasing their range of clinical indications. However, these composition alterations carried to different surface treatments protocols for cementation. Previously, the adhesive luting was the standard procedure for all ceramics; nowadays these differences in composition represent a challenge for the clinician, regarding the surface treatment and luting procedures. Thus, the objective of this revision is to establish the most suitable protocol for surface treatment and cementation of several ceramic systems, based on the structural characteristics of each material, giving assistance for a correct choice of the correct surface treatment, luting agent and adhesive system.

Fractura dental con invasión del espacio biológico - una conducta multidisciplinar / Tooth fracture with biologic width violation - multidisciplinary conduct

Las fracturas coronarias constituyen problemas dentales frecuentes, especialmente en los niños y los adolescentes. Cuando ocurre, particularmente en la región anterior, el tratamiento rehabilitador tiene la función de recuperar la función y la estética de los dientes que fueron dañados por el trauma. El recubrimiento del fragmento, cuando es posible, crea una respuesta emocional positiva en el paciente y simplifica el mantenimiento de la oclusión original. En este caso, los autores exponen el tratamiento de una fractura oblicua de corona-raíz en el incisivo lateral superior con invasión del espacio biológico. Tres años después del tratamiento, el diente mostró función normal, estética favorable y una buena salud periodontal. Podemos concluir que la técnica de recubrimiento del fragmento ofrece la posibilidad de una rehabilitación estética y funcional con características más semejantes a la dentición natural, teniendo siempre que ser considerada como una de las alternativas de tratamiento para dientes fracturados, donde se tenga el fragmento dental.

Localization and developmental regulation of a dispersed gene family 1 protein in Trypanosoma cruzi.

The dispersed gene family 1 (DGF-1) is the fifth largest gene family in the Trypanosoma cruzi genome, with over 500 members (11). Many of the predicted DGF-1 protein products have several transmembrane domains and N-glycosylation and phosphorylation sites and were thought to localize in the plasma membrane. Here, we report that affinity-purified antibodies against a region of one of these proteins (DGF-1.2) localized it intracellularly in different stages of the parasite. DGF-1.2 is more abundant in the amastigote stage than in trypomastigotes and epimastigotes, as detected by immunofluorescence and Western blot analyses. The protein changed localization during intracellular or extracellular differentiation from the trypomastigote to the amastigote stage, where it finally localized to small bodies in close contact with the inner side of the amastigote plasma membrane. DGF-1.2 did not colocalize with markers of other subcellular organelles, such as acidocalcisomes, glycosomes, reservosomes, lipid droplets, or endocytic vesicles. During extracellular differentiation, the protein was detected in the culture medium from 0 to 22 h, peaking at 14 h. The presence of DGF-1.2 in the differentiation culture medium was confirmed by mass spectrometry analysis. Finally, when epimastigotes were subjected to starvation, there was a decrease in the labeling of the cells and, in Western blots, the appearance of bands of lower molecular mass, suggesting its cleavage. These results represent the first report of direct immunodetection and developmental expression and secretion of a DGF-1 protein.

Rehabilitación estética por medio de facetas directas-presentación de casos clínicos / Aesthetic rehabilitation through direct facets - report of cases

En la actualidad, la sociedad prácticamente exige una uniformidad de las características relacionadas con la apariencia física de las personas, lo que hace aumentar la búsqueda por los tratamientos que proporcionen un aspecto más agradable, vinculado a técnicas eficientes y seguras. Las alteraciones dentarias de color, de forma, textura y/o posición contribuyen de modo desfavorable, principalmente en los dientes anteriores, para una armonía facial. El uso de las facetas estéticas, directamente en la boca, es cada vez más enfatizado debido a evolución de los materiales restauradores y de la técnica adhesiva, ofreciendo una mejor relación costo/beneficio para el paciente. El objetivo del presente artículo es presentar casos clínicos en los cuales el tratamiento con facetas directas es una alternativa de tratamiento eficaz, reversible y de fácil realización.

At present, society practically demands uniformity of features in relation to physical appearance, resulting in an increasing number of persons seeking treatment that will provide them with a more pleasant visual appearance, linked to efficient and safe techniques. Alterations in tooth shade, shape, texture and/or position, particularly of anterior teeth, contribute unfavorably to facial harmony. Aesthetic facets placed directly in the mouth have been increasingly emphasized, due to the development of restorative materials and adhesive techniques, offering the patient an even better cost/benefit ratio. The aim of this article is to present clinical cases in which the direct facet was shown to be an efficient, reversible and easy to perform alternative treatment.

Reprimo as a potential biomarker for early detection in gastric cancer.

PURPOSE: Gastric cancer is a curable disease if diagnosed at early stage. However, most cases are diagnosed at advanced stage because of the lack of screening programs. Therefore, the identification of plasma biomarkers for early detection is necessary. EXPERIMENTAL DESIGN: To search for these biomarkers, we evaluated the DNA methylation patterns of 24 genes by Methylation-specific PCR in primary tissues from 32 retrospectively collected gastric cancer cases (testing group). Correlation between methylation and gene expression was evaluated in the MKN-45 cell line after treatment with 5-aza-2'-deoxycytidine. The most frequently hypermethylated genes were next evaluated in primary tissues and plasma samples from 43 prospectively collected gastric cancer cases as well as plasma samples from 31 asymptomatic age- and gender-matched controls (validation group). RESULTS: In the testing group, 11 genes were hypermethylated in at least 50% of cases (APC, SHP1, E-cadherin, ER, Reprimo, SEMA3B, 3OST2, p14, p15, DAPK, and p16). Eight genes (BRCA1, p73, RARbeta, hMLH1, RIZI, RUNX3, MGMT, and TIMP3) were statistically associated with a particular variant of gastric cancer, the signet-ring cell type (P = 0.03). Seven genes (APC, SHP1, E-cadherin, ER, Reprimo, SEMA3B, and 3OST2) were next evaluated in the validation group. We confirm the high frequency of methylation in primary tumors for all seven genes. However, only APC and Reprimo were frequently methylated in pair plasma samples. In asymptomatic controls, only Reprimo was infrequently methylated in comparison with plasma from gastric cancer cases (P < 0.001). CONCLUSION: Our results identified specific methylation profile associated to signet-ring cell-type histology and aberrant hypermethylation of Reprimo as a potential biomarker for early detection of gastric cancer.

DNA methylation profile in diffuse type gastric cancer: evidence for hypermethylation of the BRCA1 promoter region in early-onset gastric carcinogenesis.

Diffuse type gastric carcinoma is the most aggressive type of gastric cancer. This type of tumor is not preceded by precancerous changes and is associated with early-onset and hereditary syndromes. To test the hypothesis that DNA methylation profile would be useful for molecular classification of the diffuse type gastric carcinoma, DNA methylation patterns of the CpG Island of 17 genes were studied in 104 cases and 47 normal adjacent gastric mucosa by Methylation-specific PCR, Immunohistochemistry and Hierarchical clustering analysis. The most frequent methylated genes were FHIT, E-cadherin, BRCA1 and APC (>50%), followed by p14, p16, p15, p73, MGMT and SEMA3B (20-49%). Hierarchical clustering analysis reveals four groups with different clinical features. The first was characterized by hypermethylation of BRCA1 and younger age (<45 years old), and the second by hypermethylation of p14 and p16 genes, male predominance and Epstein-Barr virus infection. The third group was characterized by hypermethylation of FHIT and antrum located tumors and the fourth was not associated with any clinical variables. In normal adjacent mucosa only the p73 gene was significantly less methylated in comparison to tumor mucosa. DNA methylation identified subgroups of diffuse type gastric cancer. Hypermethylation of BRCA1 associated with young age suggests a role in early-onset gastric carcinoma.

DNA methylation profile in diffuse type gastric cancer: evidence for hypermethylation of the BRCA1 promoter region in early-onset gastric carcinogenesis

Diffuse type gastric carcinoma is the most aggressive type of gastric cancer. This type of tumor is not preceded by precancerous changes and is associated with early-onset and hereditary syndromes. To test the hypothesis that DNA methylation profile would be useful for molecular classification of the diffuse type gastric carcinoma, DNA methylation patterns of the CpG Island of 17 genes were studied in 104 cases and 47 normal adjacent gastric mucosa by Methylation-specific PCR, Immunohistochemistry and Hierarchicalclustering analysis. The most frequent methylated genes were FHIT, E-cadherin, BRCA1 and APC (>50%),followed by p14, p16, p15, p73, MGMT and SEMA3B (20-49%). Hierarchical clustering analysis reveals four groups with different clinical features. The first was characterized by hypermethylation of BRCA1 and younger age (<45 years old), and the second by hypermethylation of p14 and p16 genes, male predominance and Epstein-Barr virus infection. The third group was characterized by hypermethylation of FHIT and antrum located tumors and the fourth was not associated with any clinical variables. In normal adjacent mucosa only the p73 gene was significantly less methylated in comparison to tumor mucosa. DNA methylation identified subgroups of diffuse type gastric cancer. Hypermethylation of BRCA1 associated with young age suggests a role in early-onset gastric carcinoma.

Epstein-Barr virus-associated primary lymphoepitheliomalike carcinoma of the esophagus.

Primary lymphoepitheliomalike carcinomas (LELC) of the esophagus are uncommon, with only 29 previously reported cases in the literature. Primary LELC of the esophagus is associated with Epstein-Barr virus (EBV). We herein report a 52-year-old man who presented with dysphagia and weight loss and was found to have a polypoid mass in the middle esophagus. Pathologic examination showed LELC. EBV infection was demonstrated by immunohistochemical detection of EBNA-1 in neoplastic cells and polymerase chain reaction amplification for EBNA-3C, BamHI-F, and W1/I1 regions but not by in situ hybridization by EBER-1 transcripts. EBV genotyping analysis demonstrated infection by a novel type "i"/XhoI loss recombinant strain. Although it is accepted that polymorphisms at BamHI-W1/I1 region cosegregate with polymorphisms at XhoI restriction site, this novel recombinant EBV has been identified in healthy donors and in nasal NK/T-cell lymphoma. To our knowledge, this is the first report that describes this recombinant type "i"/XhoI loss EBV strain in a primary LELC of the esophagus.