Search results for "blas"
showing 10 items of 2217 documents
The role of biosilica in the osteoprotegerin/RANKL ratio in human osteoblast-like cells
2010
Abstract Earlier studies have demonstrated that biosilica, synthesized by the enzyme silicatein, induces hydroxyapatite formation in osteoblast-like SaOS-2 cells. Here we study the effect of biosilica on the expressions of osteoprotegerin [OPG] and the receptor activator for NF-κB ligand [RANKL] in the SaOS-2 cell model. We show that during growth of SaOS-2 cells on biosiliceous matrices hydroxyapatite formation is induced, while syntheses of cartilaginous proteoglycans and sulfated glycosaminoglycans are down-regulated. Furthermore, quantitative real-time RT-PCR analysis revealed a strong time-depended increase in expression of OPG in biosilica exposed SaOS-2 cells while the steady-state e…
Bio-silica and bio-polyphosphate: applications in biomedicine (bone formation)
2012
Bio-silica represents the main mineral component of the sponge skeletal elements (siliceous spicules), while bio-polyphosphate (bio-polyP), a multifunctional polymer existing in microorganisms and animals acts, among others, as reinforcement for pores in cell membranes. These natural inorganic bio-polymers, which can be readily prepared, either by recombinant enzymes (bio-silica and bio-polyP) or chemically (polyP), are promising materials/substances for the amelioration and/or treatment of human bone diseases and dysfunctions. It has been demonstrated that bio-silica causes in vitro a differential effect on the expression of the genes OPG and RANKL, encoding two mediators that control the …
Type V collagen counteracts osteo-differentiation of human mesenchymal stem cells
2014
In search of novel gene signatures for osteo-differentiation of mesenchymal stem cells (MSCs), we submitted cDNA preparations from undifferentiated and differentiating MSCs to differential display- and semiquantitative-PCR and found down-regulation of COL5A1 in osteo-induced cultures at days 21 and 28, when the mineralized matrix accumulates. We also cultured osteo-differentiating MSCs onto type V collagen substrates and found a decrease in the accumulation of extracellular calcium compared to those grown in uncoated flasks. To our knowledge, this is first evidence that type V collagen might represent a stromal component that impairs osteogenesis.
CONGENITAL NEUROBLASTOMA: A RARE CASE OF PLURIVISCERAL METASTATIC DISSEMINATION
2021
Neuroblastoma is one of the most common neonatal tumors. It involves children in early infancy and originates from neural crest cells of the adrenal gland medulla or sympathetic glia. We report an unusual case of congenital poorly differentiated neuroblastoma with multiple metastases in the brain and cerebellum. The biophysical profile showed a prominent polyhydramnios at 25.3 weeks of gestation; meantime, the mother was diagnosed with gestational diabetes. The mass was detected during the third ultrasonographic examination at 31.4 weeks of gestation. The fetus lived only one day after birth and the postmortem examinations were performed subsequently. An autopsy was performed both to unders…
Integración de la genómica en la modelización de los tumores neuroblásticos = Integration of genomics in neuroblastic tumors modeling
2015
*Introducción: El neuroblastoma es un tumor maligno embrionario del sistema nervioso simpático con una gran heterogeneidad en la presentación clínica, morfológica y genética y en otras características biológicas. La estratificación de grupos de riesgo pretratamiento se basa en los siguientes factores: edad, estadio, histopatológica del tumor, estado del oncogén MYCN, integridad del brazo cromosómico 11q y ploidía. Por otra parte, los cambios numéricos y estructurales detectados en el perfil genético se han incluido recientemente en la estratificación terapéutica de los pacientes con bajo riesgo a recaer o morir. El amplio espectro clínico de la enfermedad va desde pacientes con neuroblastom…
Transmisión de señales mecánicas en células indiferenciadas neuroblásticas. Estudios biológicos y preclínicos en modelos in vitro 3D
2023
La biotensegridad es un principio físico de autoequilibrio en el que las fuerzas de tensión y compresión sostienen las estructuras biológicas y permiten la mecanotransducción de señales durante las interacciones célula-célula y célula-entorno. De esta manera, las células y los tejidos responden a las condiciones de su entorno y se adaptan a él. En este sentido, el cáncer muestra sus propios sistemas biotensegrales aberrantes que impulsan la carcinogénesis y la evolución de la enfermedad. La biotensegridad tumoral se define por la intercomunicación entre las poblaciones de células tumorales, los elementos de la matriz extracelular y las estructuras y moléculas del microambiente tumoral. En l…
Alteraciones cromosómicas segmentarias como marcador pronóstico en neuroblastoma y sarcomas pediátricos
2020
NEUROBLASTOMA Tumor descrito por primera vez en por el patólogo alemán Virchow en 1864, el neuroblastoma (NB) es el tumor sólido extracraneal más frecuente entre la población pediátrica, y forma parte de los tumores derivados del sistema nervioso simpático (en cadena simpática o ganglios simpáticos). Otros tumores también derivados de la cresta neural son el ganglioneuroblastoma y el ganglioneuroma. Las características del neuroblastoma son las siguientes: - Capacidad de madurar de formas indiferenciadas (neuroblastomas) a formas maduras (ganglioneuroma). - Capacidad de regresar espontáneamente. - Buen pronóstico en pacientes menores de un año. - Comportamiento altamente agresivo en formas …
Evaluación de una puntuación semicuantitativa de MIBG como factor pronóstico en neuroblastoma metastásico y correlación con otros factores pronóstico…
2013
SEMIQUANTITATIVE 123I-METAIODOBENZYLGUANIDINE SCORE AS A PROGNOSIS MARKER IN HIGH RISK NEUROBLASTOMA: CORRELATION WITH OTHER PROGNOSTIC MARKERS AND MINIMAL RESIDUAL DISEASE IN BONE MARROW. Purpose: Metaiodobenzylguanidine (MIBG), specifically taken up in cells of sympathetic origin, provides a highly sensitive and specific marker for the detection of metastases in neuroblastoma. Our aim has been to investigate whether response to induction therapy, evaluated by 123I-MIBG correlates with overall survival (OS) and other prognostic factors in children with metastatic neuroblastoma. Patients and Methods: Medical records and imaging studies from 28 patients with stage 4 neuroblastoma have been r…
Antitumor Cell-Complex Vaccines Employing Genetically Modified Tumor Cells and Fibroblasts
2014
The present study evaluates the immune response mediated by vaccination with cell complexes composed of irradiated B16 tumor cells and mouse fibroblasts genetically modified to produce GM-CSF. The animals were vaccinated with free B16 cells or cell complexes. We employed two gene plasmid constructions: one high producer (pMok) and a low producer (p2F). Tumor transplant was performed by injection of B16 tumor cells. Plasma levels of total IgG and its subtypes were measured by ELISA. Tumor volumes were measured and survival curves were obtained. The study resulted in a cell complex vaccine able to stimulate the immune system to produce specific anti-tumor membrane proteins (TMP) IgG. In the g…