Search results for "blast"
showing 10 items of 2136 documents
Pfeiffer syndrome: clinical and genetic findings in five Brazilian families
2014
Pfeiffer syndrome (PS) is mainly characterized by craniosysnostosis, midface hypoplasia, great toes with partial syndactyly of the digits and broad and medially deviated thumbs. It is caused by allelic mutations in the fibroblast growth factor receptor 1 and 2 (FGFR1 and 2) genes. This study describes the clinical and genetic features of five Brazilian families affected by PS. All patients exhibited the classical phenotypes related to PS. The genetic analysis was able to detect the mutations Cys278Phe, Cys342Arg, and Val359Leu in three of these families. Two mutations were de novo, with one familial. We identified pathogenic mutations in four PS cases in five Brazilian families by PCR seque…
Silicate modulates the cross-talk between osteoblasts (SaOS-2) and osteoclasts (RAW 264.7 cells): inhibition of osteoclast growth and differentiation
2012
It has been shown that inorganic monomeric and polymeric silica/silicate, in the presence of the biomineralization cocktail, increases the expression of osteoprotegerin (OPG) in osteogenic SaOS-2 sarcoma cells in vitro. In contrast, silicate does not affect the steady-state gene expression level of the osteoclastogenic ligand receptor activator of NF-κB ligand (RANKL). In turn it can be expected that the concentration ratio of the mediators OPG/RANKL increases in the presence of silicate. In addition, silicate enhances the growth potential of SaOS-2 cells in vitro, while it causes no effect on RAW 264.7 cells within a concentration range of 10-100 µM. Applying a co-cultivation assay system,…
Osteogenic differentiation of periodontal fibroblasts is dependent on the strength of mechanical strain
2012
Abstract Objective During orthodontic therapy the correct strength of mechanical strain plays a key role for bone remodelling during tooth movement. Aim of this study was to investigate the osteogenic differentiation of human periodontal ligament fibroblasts (HPdLF) depending on the applied strength of mechanical strain compared to osteoblasts (HOB). Design HPdLF and HOB were loaded with different strengths (1%, 5% and 10%) of static mechanical strain (SMS) for 12 h in vitro. Viability was verified by MTT and apoptosis by TUNEL assay. Gene expression of cyclin D1, collagen type-1 (COL-I), alkaline phosphatase (ALP), osteocalcin, osteoprotegerin (OPG) and receptor activator of the NF-κB liga…
FGFR2mutation in 46,XY sex reversal with craniosynostosis
2015
Patients with 46,XY gonadal dysgenesis (GD) exhibit genital anomalies, which range from hypospadias to complete male-to-female sex reversal. However, a molecular diagnosis is made in only 30% of cases. Heterozygous mutations in the human FGFR2 gene cause various craniosynostosis syndromes including Crouzon and Pfeiffer, but testicular defects were not reported. Here, we describe a patient whose features we would suggest represent a new FGFR2-related syndrome, craniosynostosis with XY male-to-female sex reversal or CSR. The craniosynostosis patient was chromosomally XY, but presented as a phenotypic female due to complete GD. DNA sequencing identified the FGFR2c heterozygous missense mutatio…
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…