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1.
Rev Sci Instrum ; 93(9): 093530, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36182469

RESUMO

A three-dimensional model of the hot-spot x-ray emission has been developed and applied to the study of low-mode drive asymmetries in direct-drive inertial confinement fusion implosions on OMEGA with cryogenic deuterium-tritium targets. The steady-state model assumes an optically thin plasma and the data from four x-ray diagnostics along quasi-orthogonal lines of sight are used to obtain a tomographic reconstruction of the hot spot. A quantitative analysis of the hot-spot shape is achieved by projecting the x-ray emission into the diagnostic planes and comparing this projection to the measurements. The model was validated with radiation-hydrodynamic simulations assuming a mode-2 laser illumination perturbation resulting in an elliptically shaped hot spot, which was accurately reconstructed by the model using synthetic x-ray images. This technique was applied to experimental data from implosions in polar-direct-drive illumination geometry with a deliberate laser-drive asymmetry, and the hot-spot emission was reconstructed using spherical-harmonic modes of up to ℓ = 3. A 10% stronger drive on the equator relative to that on the poles resulted in a prolate-shaped hot spot at stagnation with a large negative A2,0 coefficient of A2,0 = -0.47 ± 0.03, directly connecting the modal contribution of the hot-spot shape with the modal contribution in laser-drive asymmetry.

2.
Phys Rev E ; 106(1): L013201, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35974626

RESUMO

In laser-driven implosions for laboratory fusion, the comparison of hot-spot x-ray yield to neutron production can serve to infer hot-spot mix. For high-performance direct-drive implosions, this ratio depends sensitively on the degree of equilibration between the ion and electron fluids. A scaling for x-ray yield as a function of neutron yield and characteristic ion and electron hot-spot temperatures is developed on the basis of simulations with varying degrees of equilibration. We apply this model to hot-spot x-ray measurements of direct-drive cryogenic implosions typical of the direct-drive designs with best ignition metrics. The comparison of the measured x-ray and neutron yields indicates that hot-spot mix, if present, is below a sensitivity estimated as ∼2% by-atom mix of ablator plastic into the hot spot.

3.
Phys Rev Lett ; 127(10): 105001, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34533333

RESUMO

Statistical modeling of experimental and simulation databases has enabled the development of an accurate predictive capability for deuterium-tritium layered cryogenic implosions at the OMEGA laser [V. Gopalaswamy et al.,Nature 565, 581 (2019)10.1038/s41586-019-0877-0]. In this letter, a physics-based statistical mapping framework is described and used to uncover the dependencies of the fusion yield. This model is used to identify and quantify the degradation mechanisms of the fusion yield in direct-drive implosions on OMEGA. The yield is found to be reduced by the ratio of laser beam to target radius, the asymmetry in inferred ion temperatures from the ℓ=1 mode, the time span over which tritium fuel has decayed, and parameters related to the implosion hydrodynamic stability. When adjusted for tritium decay and ℓ=1 mode, the highest yield in OMEGA cryogenic implosions is predicted to exceed 2×10^{14} fusion reactions.

4.
Rev Sci Instrum ; 92(3): 033529, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33819982

RESUMO

Three-dimensional reconstruction algorithms have been developed, which determine the hot-spot velocity, hot-spot apparent ion temperature distribution, and fuel areal-density distribution present in laser-direct-drive inertial confinement fusion implosions on the OMEGA laser. These reconstructions rely on multiple independent measurements of the neutron energy spectrum emitted from the fusing plasma. Measurements of the neutron energy spectrum on OMEGA are made using a suite of quasi-orthogonal neutron time-of-flight detectors and a magnetic recoil spectrometer. These spectrometers are positioned strategically around the OMEGA target chamber to provide unique 3D measurements of the conditions of the fusing hot spot and compressed fuel near peak compression. The uncertainties involved in these 3D reconstructions are discussed and are used to identify a new nTOF diagnostic line of sight, which when built will reduce the uncertainty in the hot-spot apparent ion temperature distribution from 700 to <400 eV.

5.
Nature ; 565(7741): 581-586, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30700868

RESUMO

Focusing laser light onto a very small target can produce the conditions for laboratory-scale nuclear fusion of hydrogen isotopes. The lack of accurate predictive models, which are essential for the design of high-performance laser-fusion experiments, is a major obstacle to achieving thermonuclear ignition. Here we report a statistical approach that was used to design and quantitatively predict the results of implosions of solid deuterium-tritium targets carried out with the 30-kilojoule OMEGA laser system, leading to tripling of the fusion yield to its highest value so far for direct-drive laser fusion. When scaled to the laser energies of the National Ignition Facility (1.9 megajoules), these targets are predicted to produce a fusion energy output of about 500 kilojoules-several times larger than the fusion yields currently achieved at that facility. This approach could guide the exploration of the vast parameter space of thermonuclear ignition conditions and enhance our understanding of laser-fusion physics.

6.
Hum Mol Genet ; 27(22): 3827-3839, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-30007339

RESUMO

Gain-of-function mutations in fibroblast growth factor receptors (FGFRs) cause congenital skeletal anomalies, including craniosynostosis (CS), which is characterized by the premature closure of craniofacial sutures. Apert syndrome (AS) is one of the severest forms of CS, and the only treatment is surgical expansion of prematurely fused sutures in infants. Previously, we demonstrated that the prolyl isomerase peptidyl-prolyl cis-trans isomerase interacting 1 (PIN1) plays a critical role in mediating FGFR signaling and that Pin1+/- mice exhibit delayed closure of cranial sutures. In this study, using both genetic and pharmacological approaches, we tested whether PIN1 modulation could be used as a therapeutic regimen against AS. In the genetic approach, we crossbred Fgfr2S252W/+, a mouse model of AS, and Pin1+/- mice. Downregulation of Pin1 gene dosage attenuated premature cranial suture closure and other phenotypes of AS in Fgfr2S252W/+ mutant mice. In the pharmacological approach, we intraperitoneally administered juglone, a PIN1 enzyme inhibitor, to pregnant Fgfr2S252W/+ mutant mice and found that this treatment successfully interrupted fetal development of AS phenotypes. Primary cultured osteoblasts from Fgfr2S252W/+ mutant mice expressed high levels of FGFR2 downstream target genes, but this phenotype was attenuated by PIN1 inhibition. Post-translational stabilization and activation of Runt-related transcription factor 2 (RUNX2) in Fgfr2S252W/+ osteoblasts were also attenuated by PIN1 inhibition. Based on these observations, we conclude that PIN1 enzyme activity is important for FGFR2-induced RUNX2 activation and craniofacial suture morphogenesis. Moreover, these findings highlight that juglone or other PIN1 inhibitors represent viable alternatives to surgical intervention for treatment of CS and other hyperostotic diseases.


Assuntos
Acrocefalossindactilia/genética , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Craniossinostoses/genética , Peptidilprolil Isomerase de Interação com NIMA/genética , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Acrocefalossindactilia/tratamento farmacológico , Acrocefalossindactilia/fisiopatologia , Animais , Suturas Cranianas/fisiopatologia , Craniossinostoses/tratamento farmacológico , Craniossinostoses/fisiopatologia , Modelos Animais de Doenças , Feminino , Mutação com Ganho de Função/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Morfogênese , Peptidilprolil Isomerase de Interação com NIMA/antagonistas & inibidores , Naftoquinonas/administração & dosagem , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Gravidez , Cultura Primária de Células , Transdução de Sinais
7.
Kidney Cancer ; 1(1): 49-56, 2017 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-30334004

RESUMO

Background: Mutations in VHL, PBRM1, SETD2, BAP1, and KDM5C are common in clear cell renal cell carcinoma (ccRCC), and presence of certain mutations has been associated with outcomes in patients with non-metastatic disease. Limited information is available regarding the correlation between genomic alterations and outcomes in patients with metastatic disease, including response to VEGF-targeted therapy. Objective: To explore correlations between mutational profiles and cancer-specific outcomes, including response to standard VEGF-targeted agents, in patients with metastatic cc RCC. Methods: A retrospective review of 105 patients with metastatic ccRCC who had received systemic therapy and had targeted next-generation sequencing of tumors was conducted. Genomic alterations were correlated to outcomes, including overall survival and time to treatment failure to VEGF-targeted therapy. Results: The most frequent mutations were detected in VHL (83%), PBRM1 (51%), SETD2 (35%), BAP1 (24%), KDM5C (16%), and TERT (14%). Time to treatment failure with VEGF-targeted therapy differed significantly by PBRM1 mutation status (p = 0.01, median 12.0 months for MT versus 6.9 months for WT) and BAP1 mutation status (p = 0.01, median 6.4 months for MT versus 11.0 months for WT). Shorter overall survival was associated with TERT mutations (p = 0.03, median 29.6 months for MT versus 52.6 months for WT) or BAP1 mutations (p = 0.02, median 28.7 months for MT versus not reached for WT). Conclusions: Genomic alterations in ccRCC tumors have prognostic implications in patients with metastatic disease. BAP1 and TERT promoter mutations may be present in higher frequency than previously thought, and based on this data, deserve further study for their association with poor prognosis.

8.
AJNR Am J Neuroradiol ; 38(3): 485-491, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27932505

RESUMO

BACKGROUND AND PURPOSE: Glioblastoma and primary CNS lymphoma dictate different neurosurgical strategies; it is critical to distinguish them preoperatively. However, current imaging modalities do not effectively differentiate them. We aimed to examine the use of DWI and T1-weighted dynamic contrast-enhanced-MR imaging as potential discriminative tools. MATERIALS AND METHODS: We retrospectively reviewed 18 patients with primary CNS lymphoma and 36 matched patients with glioblastoma with pretreatment DWI and dynamic contrast-enhanced-MR imaging. VOIs were drawn around the tumor on contrast-enhanced T1WI and FLAIR images; these images were transferred onto coregistered ADC maps to obtain the ADC and onto dynamic contrast-enhanced perfusion maps to obtain the plasma volume and permeability transfer constant. Histogram analysis was performed to determine the mean and relative ADCmean and relative 90th percentile values for plasma volume and the permeability transfer constant. Nonparametric tests were used to assess differences, and receiver operating characteristic analysis was performed for optimal threshold calculations. RESULTS: The enhancing component of primary CNS lymphoma was found to have significantly lower ADCmean (1.1 × 10-3 versus 1.4 × 10-3; P < .001) and relative ADCmean (1.5 versus 1.9; P < .001) and relative 90th percentile values for plasma volume (3.7 versus 5.0; P < .05) than the enhancing component of glioblastoma, but not significantly different relative 90th percentile values for the permeability transfer constant (5.4 versus 4.4; P = .83). The nonenhancing portions of glioblastoma and primary CNS lymphoma did not differ in these parameters. On the basis of receiver operating characteristic analysis, mean ADC provided the best threshold (area under the curve = 0.83) to distinguish primary CNS lymphoma from glioblastoma, which was not improved with normalized ADC or the addition of perfusion parameters. CONCLUSIONS: ADC was superior to dynamic contrast-enhanced-MR imaging perfusion, alone or in combination, in differentiating primary CNS lymphoma from glioblastoma.


Assuntos
Neoplasias do Sistema Nervoso Central/diagnóstico por imagem , Diagnóstico Diferencial , Glioblastoma/diagnóstico por imagem , Linfoma/diagnóstico por imagem , Neuroimagem/métodos , Idoso , Neoplasias do Sistema Nervoso Central/patologia , Feminino , Glioblastoma/patologia , Humanos , Linfoma/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão/métodos , Curva ROC , Estudos Retrospectivos
9.
Artigo em Inglês | MEDLINE | ID: mdl-27726224

RESUMO

The purpose of this study was to develop and evaluate a navigation program for patients with thyroid cancer. The navigation program was developed following an analysis of the unmet needs of patients who underwent surgery for thyroid cancer. Ninety-nine patients in the control group received usual care, and 95 in the navigation group were managed with a navigation program during the perioperative period. The effectiveness of the navigation program was assessed by administering a questionnaire to both groups. Overall satisfaction scores were significantly higher in the navigation than in the control group (p = .025), as were satisfaction scores on the continuity of information (p < .001), the continuity of management (p = .002), the continuity of relationships with healthcare providers (p<.001), and patient empowerment (p < .001). The newly developed navigation program for patients with thyroid cancer was effective in raising satisfaction levels and in actively managing the disease during the perioperative period.


Assuntos
Navegação de Pacientes/métodos , Assistência Perioperatória/métodos , Neoplasias da Glândula Tireoide/cirurgia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Continuidade da Assistência ao Paciente , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação das Necessidades , Satisfação do Paciente , Avaliação de Programas e Projetos de Saúde , Adulto Jovem
10.
Phys Rev E ; 94(1-1): 011201, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27575069

RESUMO

It is shown that direct-drive implosions on the OMEGA laser have achieved core conditions that would lead to significant alpha heating at incident energies available on the National Ignition Facility (NIF) scale. The extrapolation of the experimental results from OMEGA to NIF energy assumes only that the implosion hydrodynamic efficiency is unchanged at higher energies. This approach is independent of the uncertainties in the physical mechanism that degrade implosions on OMEGA, and relies solely on a volumetric scaling of the experimentally observed core conditions. It is estimated that the current best-performing OMEGA implosion [Regan et al., Phys. Rev. Lett. 117, 025001 (2016)10.1103/PhysRevLett.117.025001] extrapolated to a 1.9 MJ laser driver with the same illumination configuration and laser-target coupling would produce 125 kJ of fusion energy with similar levels of alpha heating observed in current highest performing indirect-drive NIF implosions.

11.
Ann Oncol ; 27(7): 1286-91, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27056998

RESUMO

BACKGROUND: RET rearrangements are targetable, oncogenic lung cancer drivers. While previous series have shown durable clinical benefit with pemetrexed-based therapies in ALK- and ROS1-rearranged lung cancers, the benefits of pemetrexed-based treatments in patients with RET-rearranged lung cancers relative to other genomic subsets have not previously been explored. PATIENTS AND METHODS: A retrospective review of patients with pathologically confirmed stage IIIB/IV lung adenocarcinomas and evidence of a RET, ROS1, or ALK rearrangement, or a KRAS mutation was conducted. Patients were eligible if they received treatment with pemetrexed alone or in combination. The primary outcome of progression-free survival (PFS), and secondary outcomes of overall response rate (ORR, RECIST v1.1), time to progression (TTP), and time to treatment discontinuation were compared between RET-rearranged and groups of ROS1-rearranged, ALK-rearranged, and KRAS-mutant lung cancers. RESULTS: We evaluated 104 patients. Patients with RET-rearranged lung cancers (n = 18) had a median PFS of 19 months [95% confidence interval (CI) 12-not reached (NR)] that was comparable with patients with ROS1- (23 months, 95% CI 14-NR, n = 10) and ALK-rearranged (19 months, 95% CI 15-36, n = 36) lung cancers, and significantly improved compared with patients with KRAS-mutant lung cancers (6 months, 95% CI 5-9, P < 0.001, n = 40). ORR (45%), median TTP (20 months, 95% CI 17-NR), and median time to treatment discontinuation (21 months, 95% CI 6-NR) in patients with RET-rearranged lung cancers were not significantly different compared with patients with ALK- and ROS1-rearranged lung cancers, and improved compared with patients with KRAS-mutant lung cancers. CONCLUSION: Durable benefits with pemetrexed-based therapies in RET-rearranged lung cancers are comparable with ALK- and ROS1-rearranged lung cancers. When selecting therapies for patients with RET-rearranged lung cancers, pemetrexed-containing regimens should be considered.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas c-ret/genética , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Idoso , Quinase do Linfoma Anaplásico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Intervalo Livre de Doença , Feminino , Rearranjo Gênico , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Estadiamento de Neoplasias , Pemetrexede/administração & dosagem , Pemetrexede/efeitos adversos , Proteínas Proto-Oncogênicas p21(ras)/genética
12.
Phys Rev Lett ; 114(25): 255003, 2015 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-26197131

RESUMO

Estimating the level of alpha heating and determining the onset of the burning plasma regime is essential to finding the path towards thermonuclear ignition. In a burning plasma, the alpha heating exceeds the external input energy to the plasma. Using a simple model of the implosion, it is shown that a general relation can be derived, connecting the burning plasma regime to the yield enhancement due to alpha heating and to experimentally measurable parameters such as the Lawson ignition parameter. A general alpha-heating curve is found, independent of the target and suitable to assess the performance of all laser fusion experiments whether direct or indirect drive. The onset of the burning plasma regime inside the hot spot of current implosions on the National Ignition Facility requires a fusion yield of about 50 kJ.

13.
J Dent Res ; 91(5): 506-12, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22447851

RESUMO

Previous studies have shown that histone deacetylase (HDAC) inhibitors stimulate osteoblast differentiation in vitro and bone formation in vivo. However, the effects of HDAC inhibitors on odontoblasts have not been elucidated. Therefore, in this study, we examined the effect of suberoylanilide hydroxamic acid (SAHA), an HDAC inhibitor, on odontoblast differentiation using an MDPC23 odontoblast-like cell line. SAHA significantly enhanced matrix mineralization and the expression levels of odontoblast marker genes. SAHA increased the expression levels of nuclear factor I/C (Nfic) and dentin sialophosphoprotein (Dspp). Nfic bound directly to the Dspp promoter and stimulated Dspp transcription. SAHA increased both basal and Nfic-induced Dspp promoter activity. SAHA-induced Dspp promoter activity disappeared when mutations were introduced within the Nfic binding element of the Dspp promoter. Nfic knockdown by siRNA blocked SAHA stimulation of Dspp expression. These results indicate that SAHA enhances odontoblast differentiation and that SAHA increases Dspp expression, at least in part, by increasing the expression level of Nfic.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Proteínas da Matriz Extracelular/biossíntese , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Odontoblastos/efeitos dos fármacos , Fosfoproteínas/biossíntese , Sialoglicoproteínas/biossíntese , Animais , Linhagem Celular , Proteínas da Matriz Extracelular/genética , Técnicas de Silenciamento de Genes , Histona Desacetilases/metabolismo , Camundongos , Fatores de Transcrição NFI/genética , Fatores de Transcrição NFI/metabolismo , Fosfoproteínas/genética , Regiões Promotoras Genéticas , RNA Interferente Pequeno/fisiologia , Sialoglicoproteínas/genética , Regulação para Cima , Vorinostat
14.
Int J Obstet Anesth ; 18(3): 272-5, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19447602

RESUMO

Carcinoid tumours are neuroendocrine in origin and release vasoactive substances. Carcinoid tumours may be associated with carcinoid syndrome in 2-5% of patients and result in haemodynamic instability, bronchospasm, volume and electrolyte imbalance, and hyperglycaemia. We present the anaesthetic management of a 29-year-old parturient with metastatic carcinoid tumour. Although our patient did not ultimately develop carcinoid syndrome during the peripartum period, it was important that we used a multidisciplinary team approach, with close monitoring of her antenatal progress, and planned epidural analgesia for labour and delivery.


Assuntos
Analgesia Epidural/métodos , Anestesia Obstétrica/métodos , Tumor Carcinoide/cirurgia , Neoplasias Hepáticas/cirurgia , Neoplasias Pancreáticas/patologia , Complicações Neoplásicas na Gravidez/cirurgia , Adulto , Tumor Carcinoide/secundário , Feminino , Humanos , Neoplasias Hepáticas/secundário , Equipe de Assistência ao Paciente , Gravidez , Resultado do Tratamento
15.
Opt Express ; 16(11): 8250-62, 2008 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-18545537

RESUMO

In vivo retinal images of transgenic mice, expressing GFP under the control of the GFAP (glial fibrillary acidic protein) promoter, have very poor signal-to-noise ratio (SNR) and cellular resolution such that the analysis of GFAP-GFP expressing retinal cells from these images can be a very challenging task. We report an image averaging method based on a pixel rank matching criterion which significantly enhances both these image attributes. We also show that it compares favorably against direct image averaging and a commercial averaging routine available from the Heidelberg Retinal Angiograph 2 software.


Assuntos
Proteínas de Fluorescência Verde , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Proteínas do Tecido Nervoso/metabolismo , Retina/citologia , Retina/metabolismo , Retinoscopia/métodos , Animais , Perfilação da Expressão Gênica , Proteína Glial Fibrilar Ácida , Proteínas de Fluorescência Verde/genética , Camundongos , Camundongos Transgênicos , Sensibilidade e Especificidade
16.
Bone ; 30(1): 71-7, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11792567

RESUMO

Phosphatidylinositol 3-kinase (PI 3-kinase) and mitogen-activated protein kinases (MAPKs) have been implicated in diverse cellular functions, including proliferation, migration, and survival. In this study, we examined the involvement of these kinases in osteoclast differentiation by employing specific inhibitors of the kinases. The osteoclast differentiation was assessed in three different culture systems: a coculture of mouse bone marrow cells with mouse calvarial osteoblasts, a mouse bone marrow cell culture in the presence of receptor activator of NF-kappaB ligand (RANKL) and macrophage-colony stimulating factor (M-CSF), and a culture of bone-resident osteoclast precursor cells driven by RANKL and M-CSF. LY294002, a specific inhibitor of PI 3-kinase, potently inhibited osteoclast differentiation in all culture systems when assessed by both tartrate-resistant acid phosphatase (TRAP) staining and dentine resorption assays. Inhibition of p38 MAPK by SB202190 resulted in a strong suppression in the exogenous RANKL dependent mouse bone marrow and bone resident precursor cell cultures. Another MAPK pathway inhibitor (PD98059), which blocks the activation of extracellular signal-regulated kinase (ERK) by inhibiting the upstream kinase MAPK-ERK kinase (MEK) 1, exerted an inhibitory effect on osteoclast differentiation only at the highest concentration tested (30 micromol/L) in many cases. Whether the signaling pathways involving these kinases are activated by RANKL was also examined. The RANKL-stimulated phosphorylation of Akt, a downstream target of PI 3-kinase, and that of ERK were observed. RANKL also stimulated the activity of p38. These results suggest that PI 3 kinase, p38, and ERK play roles in osteoclast differentiation, at least in part, by participating in RANKL signaling.


Assuntos
Proteínas Quinases Ativadas por Mitógeno/metabolismo , Osteoclastos/citologia , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Proteínas de Transporte/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Cromonas/farmacologia , Técnicas de Cocultura , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Humanos , Imidazóis/farmacologia , MAP Quinase Quinase 1 , Fator Estimulador de Colônias de Macrófagos/farmacologia , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Morfolinas/farmacologia , Osteoblastos/citologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Piridinas/farmacologia , Ligante RANK , Receptor Ativador de Fator Nuclear kappa-B , Transdução de Sinais , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno
17.
Vasc Surg ; 35(2): 107-14, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11668378

RESUMO

Upregulation of adhesion molecules and neutrophil infiltration of venous valve cusps may be risk factors for chronic venous insufficiency. But studies that focus on the target organ (vein) fail to consider the influence of systemic inflammation on WBC behavior in the microcirculation. This study probes the gut-liver axis as a potential source of gut-derived oxidative stress and free radical production leading to white blood cell activation in chronic venous insufficiency. Venous hemodynamics (ambulatory venous pressure, air plethysmography, duplex) and gut-derived oxidative stress markers were studied in nine patients with chronic venous insufficiency (group I) and nine age- and sex-matched control subjects with no venous disease (group II). Group I had healed venous ulcers (class 5, CEAP) but near-normal ambulatory venous pressure, to eliminate high ambulatory venous pressure as a chronic venous insufficiency risk factor. Markers of gut-derived oxidative stress included: stool analysis; intestinal permeability; hepatic detoxification challenges with caffeine, salicylate, and acetaminophen; and urine lipid peroxides. Ambulatory venous pressure did not significantly differ (group I, 42.5 +/- 5.3 mm Hg; group II, 35.5 +/- 5.5 mm Hg; p = NS). Candida overgrowth in stool distinguished group I from group II (7/9 pts vs 1/9 pts, respectively; p = 0.015). Increased intestinal permeability (lactulose/mannitol ratio) was prevalent in both groups (group I 0.07 +/- 0.02, group II 0.17 +/- 0.08, p = NS; normal range, 0.01-0.03). Both groups showed similar incidence of elevated urine lipid peroxides (5/9 pts vs 6/9 pts, respectively; p = NS), yet group I exhibited underfunction of both sulfation (group I 16.8 +/- 2.9%, group II 43.3 +/- 11%, p<0.03; normal acetaminophen recovery 16-36%) and glucuronidation (group I 30.4 +/- 4.1%, group II 64.1 +/- 14.4%, p<0.04; normal acetaminophen recovery 27%-56%) relative to oxidative stress, perhaps an indicator of diminished antioxidant capacity in patients with chronic venous insufficiency. Gut dysbiosis (as indicated by stool yeast) and hepatic detoxification challenge pathway exhaustion may lead to subclinical, systemic inflammation and peripheral white blood cell adhesion in chronic venous insufficiency. Further exploration of the relationship between oxidative stress and venous disease is needed.


Assuntos
Fígado/metabolismo , Insuficiência Venosa/etiologia , Insuficiência Venosa/metabolismo , Adulto , Cafeína/metabolismo , Candida/metabolismo , Doença Crônica , Feminino , Glucuronidase/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Intestinos/microbiologia , Perna (Membro)/irrigação sanguínea , Peróxidos Lipídicos/urina , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/fisiologia , Permeabilidade , Somatomedinas/metabolismo
18.
Eur J Immunol ; 31(7): 2179-88, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11449372

RESUMO

Host immune response is known to contribute to the progression of periodontitis, and alveolar bone destruction in periodontitis is associated with enhanced osteoclast activity. Therefore, we evaluated the roles of activated lymphocyte subsets in osteoclastogenesis. Osteoclast precursors were co-cultured with activated lymphocytes (B, CD4(+) T, CD8(+) T) in the presence of either macrophage colony-stimulating factor (M-CSF) alone or M-CSF plus soluble receptor activator of NF-kappaB ligand (sRANKL), and subsequent differentiation into active osteoclasts was evaluated by a resorption assay. The activated B and CD4(+) cells, but not CD8(+) T cells, induced osteoclast differentiation in the presence of M-CSF alone. In the presence of M-CSF and sRANKL, B cells induced the formation of small but highly active osteoclasts and increased resorption, while CD8(+) T cells profoundly suppressed osteoclastogenesis. Co-culture using an insert well or supernatant suggested that both B and CD8(+) T cells acted on osteoclasts mostly via soluble proteins. Activated B cells expressed many osteoclastogenic factors including RANKL, TNF-alpha, IL-6, MIP-1alpha, and MCP-3. CD8(+) T cells expressed a substantial amount of osteoprotegerin (OPG) along with RANKL. However, blocking antibody to OPG did not reverse the suppression by CD8(+) T cells, suggesting that other factor(s) are involved. Taken together, activated B cells promoted osteoclastogenesis, while CD8(+) T cells inhibited the osteoclast formation via direct interaction. The results imply the importance of lymphocyte subpopulations in the development of periodontitis.


Assuntos
Linfócitos B/imunologia , Linfócitos T CD8-Positivos/imunologia , Osteoclastos/fisiologia , Animais , Anticorpos Monoclonais/imunologia , Linfócitos T CD4-Positivos/imunologia , Proteínas de Transporte/farmacologia , Diferenciação Celular , Células Cultivadas , Quimiocinas/biossíntese , Quimiocinas/genética , Citocinas/biossíntese , Feminino , Glicoproteínas/imunologia , Glicoproteínas/fisiologia , Ativação Linfocitária , Fator Estimulador de Colônias de Macrófagos/farmacologia , Glicoproteínas de Membrana/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Osteoclastos/citologia , Osteoprotegerina , Ligante RANK , RNA Mensageiro/biossíntese , Receptor Ativador de Fator Nuclear kappa-B , Receptores Citoplasmáticos e Nucleares/imunologia , Receptores Citoplasmáticos e Nucleares/fisiologia , Receptores do Fator de Necrose Tumoral , Células-Tronco/imunologia
19.
Mol Cell ; 7(6): 1143-52, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11430818

RESUMO

Substrates enter the proteasome core particle (CP) through a channel that opens upon association with the regulatory particle (RP). Using yeast mutants, we show that channel opening is mediated by the ATPase domain of Rpt2, one of six ATPases in the RP. To test whether degradation products exit through this channel, we analyzed their size distribution. Their median length from an open-channel CP mutant was 40% greater than that from the wild-type. Thus, channel opening may enhance the yield of peptides long enough to function in antigen presentation. These experiments demonstrate that gating of the RP channel controls both substrate entry and product release, and is specifically regulated by an ATPase in the base of the RP.


Assuntos
Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Cisteína Endopeptidases/metabolismo , Ativação do Canal Iônico/fisiologia , Complexos Multienzimáticos/metabolismo , Peptídeo Hidrolases/metabolismo , Adenosina Trifosfatases/química , Sequência de Aminoácidos , Apresentação de Antígeno/fisiologia , Cisteína Endopeptidases/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Ativação do Canal Iônico/efeitos dos fármacos , Dados de Sequência Molecular , Complexos Multienzimáticos/química , Peptídeo Hidrolases/química , Canais de Potássio/farmacologia , Complexo de Endopeptidases do Proteassoma , Estrutura Quaternária de Proteína , Especificidade por Substrato , Leveduras
20.
Biochem Biophys Res Commun ; 284(3): 850-5, 2001 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-11396980

RESUMO

Genomic alterations and abnormal expression of the fragile histidine triad (FHIT) gene in gastric carcinomas were examined to determine whether the FHIT gene is actually a frequent target for alteration during gastric carcinogenesis. To correlate DNA and RNA lesions of the FHIT gene with the effect on FHIT protein expression, we have investigated the FHIT gene for loss of heterozygosity (LOH), aberrant transcripts, point mutations, and protein expression in 35 gastric adenocarcinomas. Allelic loss at D3S1300 was detected in 7 of 33 (21%) informative cases. Aberrant transcripts, with deletions and/or insertions, were observed in 20 of 35 (57.1%) cases and resulted from alternative splicing through exon skipping and/or insertion of the FHIT intron 5 sequence or activation of the cryptic splice site. Point mutations were not found in the FHIT coding region but detected in noncoding exon 2, 3, 4, or 5 of eight aberrant transcripts. Significant reduction of FHIT protein expression was observed in 22 of 35 (62.9%) cases. Aberrant FHIT transcription was shown to be associated with loss of FHIT protein expression. However, aberrant FHIT transcripts themselves were not associated with any clinicopathological parameters, such as age, sex, tumor site, or clinical stage. Moreover, there was no association between the presence of LOH at D3S1300 and the expression of aberrant FHIT transcripts. Nevertheless, high frequency of aberrant FHIT transcripts, significant rate of LOH at D3S1300, and altered expression of the FHIT protein indicate that alterations of the FHIT gene can play an important role in gastric carcinogenesis.


Assuntos
Hidrolases Anidrido Ácido , Adenocarcinoma/genética , Proteínas de Neoplasias , Proteínas/genética , Neoplasias Gástricas/genética , Adenocarcinoma/metabolismo , Adulto , Idoso , Processamento Alternativo , DNA de Neoplasias/genética , Regulação para Baixo , Feminino , Humanos , Perda de Heterozigosidade , Masculino , Pessoa de Meia-Idade , Mutação Puntual , Proteínas/metabolismo , RNA Neoplásico/genética , Deleção de Sequência , Neoplasias Gástricas/metabolismo
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