ABSTRACT
INTRODUCTION: Head and neck cancer recurrence is a therapeutic challenge due to the anatomical and functional constraints of the head and neck area. Stereotactic body radiotherapy (SBRT) is a high-precision technique of radiotherapy that consists of delivering a high ablative biological dose in 1-5 high-dose fractions, requiring a very high precision of the radiotherapy process with potential application in this clinical setting METHODS: Different studies that investigate the role of SBRT in the treatment of recurrent head and neck cancer have been reviewed. Indications to properly select patients for this treatment are presented. RESULTS: Retrospective studies and phase I-II trials with selected patients have shown low to moderate toxicity, with an efficacy at least similar to that of treatment with combinations of radiotherapy and chemotherapy. In selected patients, SBRT is a treatment option for recurrent head and neck cancer with low toxicity. DISCUSSION: New prospective studies should clarify data regarding the efficacy and toxicity of SBRT in head and neck cancer recurrence.
Subject(s)
Head and Neck Neoplasms/radiotherapy , Neoplasm Recurrence, Local/radiotherapy , Radiosurgery/methods , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Humans , Prospective Studies , Radiosurgery/adverse effects , Re-Irradiation , Retrospective StudiesABSTRACT
Bone marrow mesenchymal stem cells (MSCs) are multipotent cells, which among other cell lineages, give rise to adipocytes and osteoblasts. Within the bone marrow, the differentiation of MSCs into adipocytes or osteoblasts is competitively balanced; mechanisms that promote one cell fate actively suppress mechanisms that induce the alternative lineage. This occurs through the cross talk between complex signaling pathways including those derived from bone morphogenic proteins (BMPs), winglesstype MMTV integration site (Wnt) proteins, hedgehogs, delta/jagged proteins, fibroblastic growth factors (FGF), insulin, insulin-like growth factors (IGF), and transcriptional regulators of adipocyte and osteoblast differentiation including peroxisome proliferator-activated receptor-gamma (PPAR gamma) and runt-related transcription factor 2 (Runx2). Here, we discuss the molecular regulation of bone marrow adipogenesis with emphasis on signals that interact with osteoblastogenic pathways and highlight the possible therapeutic implications of these interactions.
Subject(s)
Adipocytes/physiology , Adipogenesis/physiology , Bone Marrow Cells/physiology , Cell Differentiation/physiology , Mesenchymal Stem Cells/physiology , Osteoblasts/physiology , Signal Transduction/physiology , Animals , Bone Morphogenetic Proteins/metabolism , CCAAT-Enhancer-Binding Proteins/metabolism , Cell Lineage , Humans , Osteogenesis/physiology , PPAR gamma/metabolism , Protein Isoforms/metabolism , Wnt Proteins/metabolismABSTRACT
Research to date has proposed four main variables involved in reading development: phonological awareness, naming speed, orthographic knowledge, and morphological awareness. Although each of these variables has been examined in the context of one or two of the other variables, this study examines all four factors together to assess their unique contribution to reading. A sample of children in Grades 4, 6, and 8 (ages 10, 12, and 14 years) completed a battery of tests that included at least one measure of each of the four variables and two measures of reading accuracy. Phonological awareness, orthographic knowledge, and morphological awareness each contributed uniquely to real word and pseudoword reading beyond the other variables, whereas naming speed did not survive these stringent controls. The results support the sustained importance of these three skills in reading by older readers.
Subject(s)
Awareness , Comprehension , Phonetics , Reading , Speech Perception , Writing , Adolescent , Age Factors , Child , Female , Humans , MaleABSTRACT
intramedularllena de líquido cefalorraquídeo (LCR). En laetiología de toda cavidad siringomiélica subyace unaalteración en la circulación del LCR de diversa índole.Hablamos de formas "idiopáticas" cuando no se identificanmecanismos causales de la misma. El uso de procedimientosderivativos ha sido ampliamente practicadopero el resultado de los mismos, especialmente a largoplazo, no es favorable y asocian un índice de complicacionesimportante. Otras modalidades de tratamientopretenden restaurar la circulación del LCR, eliminandoasí el mecanismo causal de la cavidad. Los resultadoscon este tipo de tratamiento son mejores a la luz de laliteratura publicada. Un adecuado estudio radiológicopermite identificar el espacio problema y planear eficazmenteel abordaje.Se presenta un caso de siringomielia idiopática tratadomediante disección de bridas aracnoideas y plastiadural con buena respuesta clínica y radiológica asícomo se revisa la literatura publicada en torno a estamodalidad de siringomielia y los distintos abordajesterapéuticos (AU)
Syringomyelia is the condition in which cavities fulfilledwith CSF are found within spinal cord. Syringesare caused by obstructions of CSF pathways of differentcauses. If we can not find a cause responsible forthe blockage, we called it "idiopathic" syringomyelia.Drainage procedures have been widely used but results,especially long-term results, are not favourable and complication rate is high. Some authors prefer to restoreCSF circulation instead to drain the syrinx. Resultsof this treatment modality are better in literature thandrainage procedures. Adequate radiological studieshelp to identify problem location and to plan the approach.A case of "idiopathic" syringomyelia is presented.Treatment consisted on arachnoids webs dissection anddural plastia. Clinical and radiological response wasgood. Literature concerned about this kind of syringomyeliaand treatment modalities are reviewed (AU)
