RESUMO
With longevity, the prevalence of osteoporosis, which occurs when the activity of osteoclast surpasses that of osteoblasts, has increased in dogs. However, limited information is available on canine osteoclastogenesis. We herein described culture conditions to induce osteoclasts from canine bone marrow cells, and identified factors affecting canine osteoclastogenesis. Tartrate-resistant acid phosphatase-positive multinucleated cells were efficiently formed in a culture of bone marrow mononuclear cells with macrophage colony-stimulating factor (M-CSF 25 ng/mL) for 3 days and a subsequent culture in the presence of M-CSF (25 ng/mL) and soluble receptor activator of NF-κB ligand (RANKL 50 ng/mL) for 4 days. We previously reported in a murine cell system that gene induction of the E isoform of microphthalmia-associated transcription factor (Mitf-E) was required and sufficient for osteoclastogenesis, while transforming growth factor-ß (TGF-ß) enhanced RANKL-induced Mitf-E expression and osteoclastogenesis. Mitf-E expression also increased during RANKL-induced osteoclastogenesis in canine cells; however, TGF-ß down-regulated Mitf-E expression and osteoclastogenesis, indicating a species-dependent response. The results of the present study show that, consistent with murine cells, M-CSF and soluble RANKL enable canine bone marrow cells to differentiate into osteoclasts, and Mitf-E expression is induced during osteoclastogenesis. However, the role of TGF-ß in osteoclast formation is distinct between murine and canine cells, suggesting the necessity of analyses using canine cells to examine the factors affecting canine osteoclastogenesis.
Assuntos
Técnicas de Cultura de Células/veterinária , Fator de Transcrição Associado à Microftalmia/metabolismo , Osteoclastos/citologia , Osteogênese/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismo , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Cães , Regulação da Expressão Gênica/efeitos dos fármacos , Fator Estimulador de Colônias de Macrófagos/farmacologia , Fator de Transcrição Associado à Microftalmia/genética , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Isoformas de Proteínas/metabolismo , Ligante RANK/farmacologiaRESUMO
In this study, we evaluate dosimetric advantages of using patient-specific aperture system with intensity-modulated proton therapy (IMPT) for head and neck tumors at the shallow depth. We used four types of patient-specific aperture system (PSAS) to irradiate shallow regions less than 4 g/cm2 with a sharp lateral penumbra. Ten head and neck IMPT plans with or without aperture were optimized separately with the same 95% prescription dose and same dose constraint for organs at risk (OARs). The plans were compared using dose volume histograms (DVHs), dose distributions, and some dose indexes such as volume receiving 50% of the prescribed dose (V50 ), mean or maximum dose (Dmean and Dmax ) to the OARs. All examples verified in this study had decreased V50 and OAR doses. Average, maximum, and minimum relative reductions of V50 were 15.4%, 38.9%, and 1.0%, respectively. Dmax and Dmean of OARs were decreased by 0.3% to 25.7% and by 1.0% to 46.3%, respectively. The plans with the aperture over more than half of the field showed decreased V50 or OAR dose by more than 10%. The dosimetric advantage of patient-specific apertures with IMPT was clarified in many cases. The PSAS has some dosimetric advantages for clinical use, and in some cases, it enables to fulfill dose constraints.
Assuntos
Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/radioterapia , Órgãos em Risco/efeitos da radiação , Terapia com Prótons , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Humanos , Dosagem RadioterapêuticaRESUMO
Microphthalmia-associated transcription factor (MITF) is a transcription factor that is expressed in limited types of cells, including osteoclasts, but the expression and role of MITF during osteoclastogenesis have not been fully elucidated. The expression of the MITF-E isoform but not that of the MITF-A isoform was induced in response to differentiation stimulation towards osteoclasts by receptor activator of NF-κB ligand (RANKL) in both RAW264.7 cells and primary bone marrow cells. The RANKL-induced formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells was inhibited in RAW264.7 cells expressing siRNA for MITF-E. Transforming growth factor-ß (TGF-ß) enhanced RANKL-induced MITF-E expression and -TRAP positive multinucleated cell formation. In particular, TGF-ß potentiated the formation of larger osteoclasts. The expression levels of NFATc1, TRAP and CtsK, genes related to osteoclast development and activity, were concurrently enhanced by TGF-ß in the presence of RANKL. Furthermore, the expression of dendritic cell-specific transmembrane protein (DC-STAMP), Itgav, Itga2, Itga5, Itgb1, Itgb3 and Itgb5, genes related to cell adhesion and fusion, were up-regulated by co-treatment with TGF-ß. In particular, the regulatory expression of Itgav and Itgb5 in response to RANKL with or without TGF-ß resembled that of MITF-E. Because MITF is involved in cell fusion in some cell systems, these results imply a role for MITF-E as an enhancer of osteoclastogenesis and that RANKL-induced levels of both MITF-E mRNA and of MITF-dependent gene expression are enhanced by treatment with TGF-ß.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Fator de Transcrição Associado à Microftalmia/genética , Osteoclastos/citologia , Ligante RANK/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Fosfatase Ácida/metabolismo , Animais , Células da Medula Óssea/citologia , Catepsina K/metabolismo , Moléculas de Adesão Celular/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Isoenzimas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator de Transcrição Associado à Microftalmia/antagonistas & inibidores , Fator de Transcrição Associado à Microftalmia/metabolismo , Osteogênese , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fosfatase Ácida Resistente a TartaratoRESUMO
The tissue distribution of activin receptor-like kinase 7 (Alk7) expression, the signaling ability of Alk7 variants, and Alk7 expression in response to ß3-adrenergic receptor activation were examined. Expression levels of Alk7 varied greatly among tissues but were highest in white adipose tissue and brown adipose tissue. In addition to full-length Alk7 (Alk7-v1), Alk7-v3, an Alk7 variant, was expressed in adipose tissues, brain, and ovary. Nodal transmits signals via Alk7 in cooperation with its coreceptor, Cripto. Evaluation of the ability of Alk7 variants to confer Nodal signaling using luciferase-based reporter assays showed that Alk7-v3 does not transmit Nodal-Cripto-mediated signals. Expression of Alk7 was down-regulated in brown but not in white adipose tissue treated with CL316,243, a ß3-adrenergic receptor agonist. These results suggest involvement of Alk7 in modulation of metabolism in the adipose tissues in response to ß3-adrenergic receptor activation.
Assuntos
Receptores de Ativinas Tipo I/biossíntese , Tecido Adiposo/enzimologia , Receptores de Ativinas Tipo I/genética , Receptores de Ativinas Tipo I/isolamento & purificação , Animais , Encéfalo/enzimologia , Variação Genética , Células Hep G2 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pâncreas/enzimologia , Próstata/enzimologia , Reação em Cadeia da Polimerase em Tempo Real , Receptores Adrenérgicos beta 3/fisiologiaRESUMO
The clinical utility of a recently developed bioabsorbable polyglycolic acid (PGA) spacer has not yet been established in pediatric patients; therefore, we aimed to investigate its utility during chemo-proton therapy for pediatric cancer. Proton depth-dose curves were obtained in a water phantom with or without the spacer. Computed tomography (CT) scans were performed for the PGA spacer immersed in saline for 2 weeks to measure CT numbers and estimate the relative stopping power (RSP) for the proton beams. The spacer was placed in a patient with sacral Ewing sarcoma receiving 55.8 Gy [relative biological effectiveness (RBE)] in 31 fractions and was evaluated using CT scans performed every other week. In addition, the images were used to quantitatively evaluate changes in volume and RSP of the spacer and dose distributions in normal tissues. The spacer immersed in saline had a CT number of 91 ± 7 (mean ± standard deviation) Hounsfield units, and the corresponding RSP was predicted to be 1.07 ± 0.01. The measured RSP agreed with the predicted one. The volumes of the large bowel and rectum receiving ≥45 Gy(RBE) (V45Gy) were significantly reduced by placing the spacer; V45Gy without and with the spacer were 48.5 and 0.01%, respectively, for the rectum and 7.2 and 0%, respectively, for the large bowel. The volume of the spacer and RSP decreased at rates of 4.6 and 0.44% per week, respectively, whereas the target dose coverage was maintained until the end of treatment. The PGA spacer was considered effective for pediatric cancer patients undergoing chemo-proton therapy.
Assuntos
Implantes Absorvíveis , Quimiorradioterapia/métodos , Ácido Poliglicólico/química , Sarcoma de Ewing/radioterapia , Criança , Relação Dose-Resposta à Radiação , Humanos , Masculino , Órgãos em Risco , Imagens de Fantasmas , Terapia com Prótons , Radiometria , Planejamento da Radioterapia Assistida por Computador/métodos , Eficiência Biológica Relativa , Fatores de Tempo , Tomografia Computadorizada por Raios XRESUMO
PURPOSE: Suppression of respiratory movement of the liver would be desirable for high-precision radiation therapy for liver tumors. We aimed to investigate the effect of our original device-free compressed shell fixation method and breathing instruction on suppression of respiratory movement. The characteristics of liver motion based on the movement of a fiducial marker were also analyzed. METHODS AND MATERIALS: First, respiratory amplitudes of the liver with the device-free compressed shell were analyzed from the data of 146 patients. The effect of this shell fixing method on liver movement was evaluated. Second, as another cohort study with 166 patients, interfractional internal motion of the liver for patients fixed in the shell was calculated using the fiducial marker coordinate data of images for position setting before daily irradiation. Third, in another 12 patients, intrafractional internal motion was calculated from the fiducial marker coordinate data using x-ray images before and after irradiation. RESULTS: The median respiratory movement without the shell, after fixing with the shell, and after instructing on the breathing method with the shell was 14.2 (interquartile range, 10.7-19.8), 11.5 (8.6-17.5), and 10.4 mm (7.3-15.8), respectively. Systematic and random errors of interfractional internal motion were all ≤2 mm in the left-right and anteroposterior directions and 3.7 and 3.0 mm, respectively, in the craniocaudal direction. Systematic and random errors of intrafractional internal motion were all ≤1.3 mm in the left-right and anteroposterior directions and 0.8 and 2.4 mm, respectively, in the craniocaudal direction. CONCLUSIONS: The device-free compressed shell fixation method was effective in suppressing the respiratory movement of the liver. Irradiation position matching using the fiducial marker can correct the interfractional internal motion on each day, which would contribute to the reduction of the margin to be given around the target.
Assuntos
Neoplasias Hepáticas/radioterapia , Movimentos dos Órgãos , Posicionamento do Paciente/métodos , Terapia com Prótons/métodos , Radioterapia Guiada por Imagem/métodos , Marcadores Fiduciais , Humanos , Fígado/diagnóstico por imagem , Fígado/fisiologia , Neoplasias Hepáticas/diagnóstico por imagem , Masculino , Estudos Prospectivos , Planejamento da Radioterapia Assistida por Computador/métodos , Mecânica Respiratória/fisiologia , Decúbito Dorsal , Tomografia Computadorizada por Raios XRESUMO
The purpose of this paper is to describe an outline of a proton therapy system in Nagoya Proton Therapy Center (NPTC). The NPTC has a synchrotron with a linac injector and three treatment rooms: two rooms are equipped with a gantry and the other one is equipped with a fixed horizontal beamline. One gantry treatment room has a pencil beam scanning treatment delivery nozzle. The other two treatment rooms have a passive scattering treatment delivery nozzle. In the scanning treatment delivery nozzle, an energy absorber and an aperture system to treat head and neck cancer have been equipped. In the passive treatment delivery nozzle, a multi-leaf collimator is equipped. We employ respiratory gating to treat lung and liver cancers for passive irradiation. The proton therapy system passed all acceptance tests. The first patient was treated on February 25, 2013, using passive scattering fixed beams. Respiratory gating is commonly used to treat lung and liver cancers in the passive scattering system. The MLCs are our first choice to limit the irradiation field. The use of the aperture for scanning irradiation reduced the lateral fall off by half or less. The energy absorber and aperture system in scanning delivery is beneficial to treat head and neck cancer.
Assuntos
Terapia com Prótons , Relação Dose-Resposta à Radiação , Humanos , Japão , Interpretação de Imagem Radiográfica Assistida por Computador , Dosagem RadioterapêuticaRESUMO
PURPOSE: In the authors' proton therapy system, the patient-specific aperture can be attached to the nozzle of spot scanning beams to shape an irradiation field and reduce lateral fall-off. The authors herein verified this system for clinical application. METHODS: The authors prepared four types of patient-specific aperture systems equipped with an energy absorber to irradiate shallow regions less than 4 g/cm(2). The aperture was made of 3-cm-thick brass and the maximum water equivalent penetration to be used with this system was estimated to be 15 g/cm(2). The authors measured in-air lateral profiles at the isocenter plane and integral depth doses with the energy absorber. All input data were obtained by the Monte Carlo calculation, and its parameters were tuned to reproduce measurements. The fluence of single spots in water was modeled as a triple Gaussian function and the dose distribution was calculated using a fluence dose model. The authors compared in-air and in-water lateral profiles and depth doses between calculations and measurements for various apertures of square, half, and U-shaped fields. The absolute doses and dose distributions with the aperture were then validated by patient-specific quality assurance. Measured data were obtained by various chambers and a 2D ion chamber detector array. RESULTS: The patient-specific aperture reduced the penumbra from 30% to 70%, for example, from 34.0 to 23.6 mm and 18.8 to 5.6 mm. The calculated field width for square-shaped apertures agreed with measurements within 1 mm. Regarding patient-specific aperture plans, calculated and measured doses agreed within -0.06% ± 0.63% (mean ± SD) and 97.1% points passed the 2%-dose/2 mm-distance criteria of the γ-index on average. CONCLUSIONS: The patient-specific aperture system improved dose distributions, particularly in shallow-region plans.