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1.
Scand J Rheumatol ; 52(5): 481-492, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-36745114

RESUMEN

OBJECTIVE: To evaluate whether disease activity-guided tapering of biologics compared to continuation as usual care enables a substantial dose reduction while disease activity remains equivalent. METHOD: In this pragmatic, randomized, open-label, equivalence trial, adults with rheumatoid arthritis, psoriatic arthritis, or axial spondyloarthritis in low disease activity on stable-dose biologics for ≥ 12 months were randomized 2:1 into either the tapering group, i.e. disease activity-guided prolongation of the biologic dosing interval until flare or withdrawal, or the control group, i.e. maintaince of baseline biologics with a possible small interval increase at the patients request. The co-primary outcome in the intention-to-treat population was met if superiority in ≥ 50% biologic reduction at 18 months was demonstrated and disease activity was equivalent (equivalence margins ± 0.5). RESULTS: Ninety-five patients were randomized to tapering and 47 to control, of whom 37% (35/95) versus 2% (1/47) achieved ≥ 50% biologic reduction at 18 months. The risk difference was statistically significant [35%, 95% confidence interval (CI) 24%-45%], while disease activity remained equivalent [mean difference 0.05, 95% CI -0.12-0.29]. A statistically significant flare risk was observed [tapering 41% (39/95) vs control 21% (10/47), risk difference 20%, 95% CI 4%-35%]; but, only 1% (1/95) and 6% (3/47) had persistent flare and needed to switch to another biological drug. CONCLUSIONS: Disease activity-guided tapering of biologics in patients with inflammatory arthritis enabled one-third to achieve ≥ 50% biologic reduction, while disease activity between groups remained equivalent. Flares were more frequent in the tapering group but were managed with rescue therapy.


Asunto(s)
Antirreumáticos , Artritis Reumatoide , Productos Biológicos , Adulto , Humanos , Antirreumáticos/uso terapéutico , Adalimumab/uso terapéutico , Etanercept/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Factores Biológicos , Productos Biológicos/uso terapéutico
2.
Scand J Rheumatol ; 51(1): 25-33, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34151710

RESUMEN

Objectives: In Denmark, patients with inflammatory arthritis (IA) have completed patient-reported outcome measures (PROMs) via touchscreens in the outpatient clinic since 2006. However, current technology makes it possible for patients to use their own smartphone via an application (app) developed for the Danish Rheumatology Database (DANBIO). This study aims to evaluate the agreement of PROMs between the DANBIO app and outpatient touchscreen in patients with IA.Method: Patients with IA (rheumatoid arthritis, psoriatic arthritis, and axial spondyloarthritis) were enrolled in a randomized, crossover, agreement study. Participants answered PROMs through the two device types in a randomized order. Differences in PROM scores with 95% confidence intervals (CIs) were evaluated for similarity according to prespecified equivalence margins.Results: The touchscreen invitation was accepted by 138 patients. Sixty patients (20 with each diagnosis) were included. The difference in Health Assessment Questionnaire Disability Index between the two device types was -0.007 (95% CI -0.043 to 0.030); thus, equivalence was demonstrated. In addition, all other PROMs obtained with the two device types were equivalent, except for the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), which was within the limits of minimally clinically important difference (MCID). In total, 78.3% preferred the DANBIO app.Conclusion: In patients with IA, equivalence was demonstrated between two device types for all PROMs except BASDAI; however, BASDAI was within the limits of the MCID. Implementation of the DANBIO app is expected to optimize outpatient visits, thereby improving healthcare for the individual patient and society.


Asunto(s)
Artritis Psoriásica , Artritis Reumatoide , Aplicaciones Móviles , Espondilitis Anquilosante , Artritis Psoriásica/diagnóstico , Artritis Psoriásica/terapia , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/terapia , Humanos , Medición de Resultados Informados por el Paciente , Índice de Severidad de la Enfermedad , Teléfono Inteligente , Espondilitis Anquilosante/diagnóstico
3.
RMD Open ; 6(1)2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32371431

RESUMEN

OBJECTIVE: To compare improvement in pain and physical function for patients treated with baricitinib, adalimumab, tocilizumab and tofacitinib monotherapy from randomised, methotrexate (MTX)-controlled trials in conventional synthetic disease-modifying antirheumatic drugs (csDMARDs)/biologic (bDMARD)-naïve RA patients using matching-adjusted indirect comparisons (MAICs). METHODS: Data were from Phase III trials on patients receiving monotherapy baricitinib, tocilizumab, adalimumab, tofacitinib or MTX. Pain was assessed using a visual analogue scale (0-100 mm) and physical function using the Health Assessment Questionnaire-Disability Index (HAQ-DI). An MAIC based on treatment-arm matching, an MAIC with study-level matching and Bucher's method without matching compared change in outcomes between therapies. Matching variables included age, gender, baseline disease activity and baseline value of outcome measure. RESULTS: With all methods, greater improvements were observed in pain and HAQ-DI at 6 months for baricitinib compared with adalimumab and tocilizumab (p<0.05). Differences in treatment effects (TEs) favouring baricitinib for pain VAS for treatment-arm matching, study-level matching and Bucher's method, respectively, were -12, -12 and -12 for baricitinib versus adalimumab and -7, -7 and -9 for baricitinib versus tocilizumab; the difference in TEs for HAQ-DI was -0.28, -0.28 and -0.30 for adalimumab and -0.23, -0.23 and -0.26 for tocilizumab. For baricitinib versus tofacitinib, no statistically significant differences for pain improvement were observed except with one of the three methods (Bucher method) and none for HAQ-DI. CONCLUSIONS: Results suggest greater pain reduction and improved physical function for baricitinib monotherapy compared with tocilizumab and adalimumab monotherapy. No statistically significant differences in pain reduction and improved physical function were observed between baricitinib and tofacitinib with the MAIC analyses.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Productos Biológicos/uso terapéutico , Metotrexato/uso terapéutico , Dolor/tratamiento farmacológico , Adalimumab , Anticuerpos Monoclonales Humanizados , Artritis Reumatoide/complicaciones , Azetidinas , Ensayos Clínicos Fase III como Asunto , Evaluación de la Discapacidad , Humanos , Metaanálisis en Red , Dimensión del Dolor , Piperidinas , Purinas , Pirazoles , Pirimidinas , Ensayos Clínicos Controlados Aleatorios como Asunto , Sulfonamidas , Resultado del Tratamiento
4.
US CLIVAR Rep ; n/a2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31633127

RESUMEN

The Arctic has warmed more than twice as fast as the global average since the mid 20th century, a phenomenon known as Arctic amplification (AA). These profound changes to the Arctic system have coincided with a period of ostensibly more frequent events of extreme weather across the Northern Hemisphere (NH) mid-latitudes, including extreme heat and rainfall events and recent severe winters. Though winter temperatures have generally warmed since 1960 over mid-to-high latitudes, the acceleration in the rate of warming at high-latitudes, relative to the rest of the NH, started approximately in 1990. Trends since 1990 show cooling over the NH continents, especially in Northern Eurasia. The possible link between Arctic change and mid-latitude climate and weather has spurred a rush of new observational and modeling studies. A number of workshops held during 2013-2014 have helped frame the problem and have called for continuing and enhancing efforts for improving our understanding of Arctic-mid-latitude linkages and its attribution to the occurrence of extreme climate and weather events. Although these workshops have outlined some of the major challenges and provided broad recommendations, further efforts are needed to synthesize the diversified research results to identify where community consensus and gaps exist. Building upon findings and recommendations of the previous workshops, the US CLIVAR Working Group on Arctic Change and Possible Influence on Mid-latitude Climate and Weather convened an international workshop at Georgetown University in Washington, DC, on February 1-3, 2017. Experts in the fields of atmosphere, ocean, and cryosphere sciences assembled to assess the rapidly evolving state of understanding, identify consensus on knowledge and gaps in research, and develop specific actions to accelerate progress within the research community. With more than 100 participants, the workshop was the largest and most comprehensive gathering of climate scientists to address the topic to date. In this white paper, we synthesize and discuss outcomes from this workshop and activities involving many of the working group members. WORKSHOP FINDINGS: Rapid Arctic change - Emergence of new forcing (external and internal) of atmospheric circulation: Rapid Arctic change is evident in the observations and is simulated and projected by global climate models. AA has been attributed to sea ice and snow decline (regionally and seasonally varying). However this cannot explain why AA is greatest in winter and weakest in summer. It was argued at the workshop that other factors can also greatly contribute to AA including: increased downwelling longwave radiation from greenhouse gases (including greater water vapor concentrations from local and remote sources); increasing ocean heat content, due to local and remote processes; regional and hemispheric atmospheric circulation changes; increased poleward heat transport in the atmosphere and ocean; and cloud radiative forcing. In particular, there is emerging observational evidence that an enhanced poleward transport of sensible and latent heat plays a very important role in the AA of the recent decades, and that this enhancement is mostly fueled by changes in the atmospheric circulation. We concluded that our understanding of AA is incomplete, especially the relative contributions from the different radiative, thermodynamic, and dynamic processes.Arctic mid-latitude linkages - Focusing on seasonal and regional linkages and addressing sources of inconsistency and uncertainty among studies: The topic of Arctic mid-latitude linkages is controversial and was vigorously debated at the workshop. However, we concluded that rapid Arctic change is contributing to changes in mid-latitude climate and weather, as well as the occurrence of extreme events. But how significant the contribution is and what mechanisms are responsible are less well understood. Based on the synthesis efforts of observational and modeling studies, we identified a list of proposed physical processes or mechanisms that may play important roles in linking Arctic change to mid-latitude climate and weather. The list, ordered from high to low confidence, includes: increasing geopotential thickness over the polar cap; weakening of the thermal wind; modulating stratosphere-troposphere coupling; exciting anomalous planetary waves or stationary Rossby wave trains in winter and modulating transient synoptic waves in summer; altering storm tracks and behavior of blockings; and increasing frequency of occurrence of summer wave resonance. The pathway considered most robust is the propagation of planetary/Rossby waves excited by the diminished Barents-Kara sea ice, contributing to a northwestward expansion and intensification of the Siberian high leading to cold Eurasian winters. OPPORTUNITIES AND RECOMMENDATIONS: An important goal of the workshop was achieved: to hasten progress towards consensus understanding and identification of knowledge gaps. Based on the workshop findings, we identify specific opportunities to utilize observations and models, particularly a combination of them, to enable and accelerate progress in determining the mechanisms of rapid Arctic change and its mid-latitude linkages.Observations: Due to the remoteness and harsh environmental conditions of the Arctic, in situ observational time series are highly limited spatially and temporally in the region.Six recommendations to expand approaches using observational datasets and analyses of Arctic change and mid-latitude linkages include: Synthesize new Arctic observations;Create physically-based sea ice-ocean surface forcing datasets;Systematically employ proven and new metrics;Analyze paleoclimate data and new longer observational datasets;Utilize new observational analysis methods that extend beyond correlative relationships; andConsider both established and new theories of atmospheric and oceanic dynamics to interpret and guide observational and modeling studies.Model experiments: We acknowledge that models provide the primary tool for gaining a mechanistic understanding of variability and change in the Arctic and at mid-latitudes. Coordinated modeling studies should include approaches using a hierarchy of models from conceptual, simple component, or coupled models to complex atmospheric climate models or fully coupled Earth system models. We further recommend to force dynamical models with consistent boundary forcings.Three recommendations to advance modeling and synthesis understanding of Arctic change and mid-latitude linkages include: Establish a Modeling Task Force to plan protocols, forcing, and output parameters for coordinated modeling experiments (Polar Amplification Model Intercomparison Project; PAMIP);Furnish experiment datasets to the community through open access (via Earth System Grid); andPromote analysis within the community of the coordinated modeling experiments to understand mechanisms for AA and to further understand pathways for Arctic mid-latitude linkages.

5.
Ann Rheum Dis ; 76(6): 998-1008, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27993829

RESUMEN

OBJECTIVES: To evaluate the efficacy and safety of different doses and regimens of filgotinib, an oral Janus kinase 1 inhibitor, as add-on treatment to methotrexate (MTX) in patients with active rheumatoid arthritis (RA) and inadequate response to MTX. METHODS: In this 24-week phase IIb study, patients with moderate-to-severe active RA receiving a stable dose of MTX were randomised (1:1:1:1:1:1:1) to receive placebo or 50, 100 or 200 mg filgotinib, administered once daily or twice daily. Primary end point was the percentage of patients achieving a week 12 American College of Rheumatology (ACR)20 response. RESULTS: Overall, 594 patients were randomised and treated. At week 12, significantly more patients receiving filgotinib 100 mg once daily or 200 mg daily (both regimens) achieved an ACR20 response versus placebo. For other key end points at week 12 (ACR50, ACR-N, Disease Activity Score based on 28 joints and C reactive protein value, Clinical Disease Activity Index, Simplified Disease Activity Index and Health Assessment Questionnaire-Disability Index), differences in favour of 100  or 200 mg filgotinib daily were seen versus placebo; responses were maintained or improved through to week 24. Rapid onset of action and dose-dependent responses were observed for most efficacy end points and were associated with an increased haemoglobin concentration. No significant differences between once-daily and twice-daily regimens were seen. Treatment-emergent adverse event rates were similar in placebo and filgotinib groups. Serious infections occurred in one and five patients in the placebo and filgotinib groups, respectively. No tuberculosis or opportunistic infections were reported. CONCLUSIONS: Filgotinib as add-on to MTX improved the signs and symptoms of active RA over 24 weeks and was associated with a rapid onset of action. Filgotinib was generally well tolerated. TRIAL REGISTRATION NUMBER: NCT01888874.


Asunto(s)
Artritis Reumatoide/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/administración & dosificación , Piridinas/administración & dosificación , Triazoles/administración & dosificación , Administración Oral , Antirreumáticos/uso terapéutico , Artritis Reumatoide/sangre , Proteína C-Reactiva/metabolismo , Evaluación de la Discapacidad , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Quimioterapia Combinada/efectos adversos , Femenino , Hemoglobinas/metabolismo , Humanos , Infecciones/inducido químicamente , Janus Quinasa 1/antagonistas & inhibidores , Masculino , Metotrexato/uso terapéutico , Persona de Mediana Edad , Inhibidores de Proteínas Quinasas/efectos adversos , Piridinas/efectos adversos , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Triazoles/efectos adversos
6.
Clin Exp Immunol ; 181(3): 401-6, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25766640

RESUMEN

We investigated changes in circulating T helper type 17 (Th17) cells following anti-tumour necrosis factor (TNF) in rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) patients. Peripheral blood mononuclear cells (PBMC) were isolated from 25 RA, 15 AS and eight PsA patients at baseline 4 and 12 weeks after treatment, and Th17 cell frequencies were analysed using interleukin (IL)-17 enzyme-linked immunospot (ELISPOT) and flow cytometry. A significant increase in IL-17-producing cells was observed by ELISPOT in RA and AS patients at 12 weeks. Flow cytometry confirmed significant increases in CD4(+) IL-17(+) cells at 12 weeks in RA and AS and 4 weeks in PsA patients. Anti-TNF treatment increases circulating Th17 cells in three different diseases.


Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Psoriásica/tratamiento farmacológico , Artritis Reumatoide/tratamiento farmacológico , Espondilitis Anquilosante/tratamiento farmacológico , Células Th17/efectos de los fármacos , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adalimumab , Adulto , Anciano , Anticuerpos Monoclonales Humanizados/uso terapéutico , Artritis Psoriásica/sangre , Artritis Reumatoide/sangre , Ensayo de Inmunoadsorción Enzimática , Etanercept , Femenino , Citometría de Flujo , Humanos , Inmunoglobulina G/uso terapéutico , Interleucina-17/sangre , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Receptores del Factor de Necrosis Tumoral/uso terapéutico , Espondilitis Anquilosante/sangre , Células Th17/metabolismo , Factores de Tiempo , Resultado del Tratamiento
7.
Ann Rheum Dis ; 74(3): 611-7, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24336336

RESUMEN

OBJECTIVE: To determine the tolerability, safety and yield of synovial tissue in an early arthritis cohort using a minimally invasive, ultrasound (US)-guided, synovial biopsy technique in small, medium and large joints. METHODS: 93 sequential biopsy procedures were assessed from a total of 57 patients (baseline and 36 repeat biopsies at 6 months) recruited as part of the 'Pathobiology of Early Arthritis Cohort' study. Patients completed a tolerability questionnaire prior to and following the synovial biopsy procedure. The synovial biopsy was performed under US guidance with US images of the joint recorded prior to each procedure. Synovial tissue was harvested for immunohistochemistry and RNA extraction. RESULTS: Five different joint sites were biopsied (knee, elbow, wrist, metacarpal phalangeal and proximal interphalangeal). No significant complications were reported following the procedure. No difference in pain, swelling and stiffness of the biopsied joint from before and after the procedure was demonstrated. A median of 14 biopsy samples was retrieved from each procedure with 93% of biopsy procedures yielding good quality tissue. RNA yield was good in all joints and in repeat biopsies. Multivariant analysis demonstrated a significantly greater yield of RNA and graded tissue in relation to a high prebiopsy, grey-scale synovitis score (0-3, semiquantitative). CONCLUSIONS: A minimally invasive approach to synovial tissue harvesting, using US guidance, is both safe and well-tolerated by patients. Tissue quality/RNA yield is preserved in subsequent biopsies following therapeutic intervention. A high US grey-scale synovitis score is a predictor of good quality/quantity of tissue and RNA.


Asunto(s)
Artritis Reumatoide/patología , Articulación del Codo/patología , Articulaciones de la Mano/patología , Biopsia Guiada por Imagen , Articulación de la Rodilla/patología , ARN/análisis , Membrana Sinovial/patología , Sinovitis/patología , Adulto , Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/metabolismo , Estudios de Cohortes , Articulación del Codo/diagnóstico por imagen , Femenino , Articulaciones de la Mano/diagnóstico por imagen , Humanos , Articulación de la Rodilla/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Membrana Sinovial/diagnóstico por imagen , Membrana Sinovial/metabolismo , Sinovitis/diagnóstico por imagen , Sinovitis/metabolismo , Ultrasonografía
8.
Rev Sci Instrum ; 84(8): 083901, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24007073

RESUMEN

Quasi-optical (QO) methods of dielectric spectroscopy are well established in the millimeter and submillimeter frequency bands. These methods exploit standing wave structure in the sample produced by a transmitted Gaussian beam to achieve accurate, low-noise measurement of the complex permittivity of the sample [e.g., J. A. Scales and M. Batzle, Appl. Phys. Lett. 88, 062906 (2006); R. N. Clarke and C. B. Rosenberg, J. Phys. E 15, 9 (1982); T. M. Hirovnen, P. Vainikainen, A. Lozowski, and A. V. Raisanen, IEEE Trans. Instrum. Meas. 45, 780 (1996)]. In effect the sample itself becomes a low-Q cavity. On the other hand, for optically thin samples (films of thickness much less than a wavelength) or extremely low loss samples (loss tangents below 10(-5)) the QO approach tends to break down due to loss of signal. In such a case it is useful to put the sample in a high-Q cavity and measure the perturbation of the cavity modes. Provided that the average mode frequency divided by the shift in mode frequency is less than the Q (quality factor) of the mode, then the perturbation should be resolvable. Cavity perturbation techniques are not new, but there are technological difficulties in working in the millimeter/submillimeter wave region. In this paper we will show applications of cavity perturbation to the dielectric characterization of semi-conductor thin films of the type used in the manufacture of photovoltaics in the 100 and 350 GHz range. We measured the complex optical constants of hot-wire chemical deposition grown 1-µm thick amorphous silicon (a-Si:H) film on borosilicate glass substrate. The real part of the refractive index and dielectric constant of the glass-substrate varies from frequency-independent to linearly frequency-dependent. We also see power-law behavior of the frequency-dependent optical conductivity from 316 GHz (9.48 cm(-1)) down to 104 GHz (3.12 cm(-1)).

9.
Osteoarthritis Cartilage ; 20(1): 29-35, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22040861

RESUMEN

OBJECTIVE: To determine the stability and reproducibility of the sodium magnetic resonance imaging (MRI) signal measured in the articular cartilage of the knee in both healthy volunteers and osteoarthritis (OA) patients. DESIGN: This was a prospective Research Ethics Committee approved study that acquired sodium and proton MRI data from 15 subjects with OA (three males, age 64 ± 10) and five healthy controls age and sex matched over the group. Each subject underwent standing planar radiographs of their knees for radiological scoring as well as symptomatological assessment questionnaires. In two MRI sessions on the same day, high resolution double-echo steady state (DESS) and 3D short echo time sodium MRI images of the most diseased knee were acquired and co-registered in each session. A blinded reader (LT) manually delineated the articular cartilage into four discrete regions, and two combined regions, on the DESS images. These regions were applied to the sodium images, and a median sodium signal from each reported. Within-subject and between-subject coefficients of variation were estimated and intraclass correlation coefficients for the healthy control group, OA subject group, and all pooled subjects group were calculated. RESULTS: Within-subject variability of sodium MRI at 3T was 3.2% overall, and 2.0% in healthy age-matched volunteers compared to a reproducibility of 3.6% on OA subjects. CONCLUSIONS: The reproducibility of sodium MRI was similar in both healthy controls and OA subjects. Researchers piloting techniques in healthy controls thus may expect a similar reproducibility in a controlled trial involving subjects with American College of Rheumatology (ACR)-defined OA of the knee.


Asunto(s)
Cartílago Articular/patología , Imagen por Resonancia Magnética/métodos , Osteoartritis de la Rodilla/diagnóstico , Sodio/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Antropometría/métodos , Biomarcadores/metabolismo , Cartílago Articular/metabolismo , Progresión de la Enfermedad , Métodos Epidemiológicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
10.
J Phys Condens Matter ; 23(5): 055502, 2011 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-21406910

RESUMEN

We present a theoretical study of the nuclear quadrupole interaction, ν(Q), of (75)As in crystalline and amorphous materials containing sulfur and selenium, and compare them with experiment. We studied a combination of hydrogen-terminated molecular clusters and periodic cells at various levels of quantum chemical theory. The results show clearly that the standard density functional theory (DFT) approximations, LDA and GGA, underestimate the nuclear quadrupole (NQR) interaction systematically, while Hartree-Fock theory overestimates it to an even greater degree. However, various levels of configuration interaction and the B3LYP hybrid exchange-correlation functional, which includes some exact exchange, give very good quantitative agreement for As bonded only to the chalcogen species. As-As bonds require highly converged basis sets. We have performed a systematic study of the effect of local distortions around an arsenic atom on ν(Q) and η. Using a simple, semiclassical model, we have combined our total energy results with our NQR calculations to predict ν(Q) lineshapes for bond angle and bond length distortions. Our predictions for lineshape, including first and second moments, are in excellent agreement with the results of Su et al for a-As(2)S(3), a-As(2)Se(3) and a-AsSe. We offer new insight into the distortions that led to this inhomogeneous broadening. Our results show clearly that, for trivalent arsenic atoms with zero or one arsenic nearest neighbor, symmetric bond stretching is the predominant contributor to the ν(Q) linewidth. However, in the presence of two arsenic nearest neighbors, distortions of the As-As-As apex angle dominates and, in fact, leads to a much larger second moment, in agreement with experiment.

12.
Arthritis Rheum ; 54(9): 2817-29, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16947782

RESUMEN

OBJECTIVE: To establish the safety and efficacy of repeat infusions of tocilizumab (previously known as MRA), a humanized anti-interleukin-6 (IL-6) receptor antibody, alone and in combination with methotrexate (MTX), for the treatment of rheumatoid arthritis (RA). METHODS: The study group comprised 359 patients with active RA in whom the response to MTX was inadequate. During a stabilization period, these patients received their current dose of MTX for at least 4 weeks. Following stabilization, they were randomized to 1 of 7 treatment arms, as follows: tocilizumab at doses of 2 mg/kg, 4 mg/kg, or 8 mg/kg either as monotherapy or in combination with MTX, or MTX plus placebo. RESULTS: A 20% response (improvement) according to the American College of Rheumatology criteria (ACR20 response) was achieved by 61% and 63% of patients receiving 4 mg/kg and 8 mg/kg of tocilizumab as monotherapy, respectively, and by 63% and 74% of patients receiving those doses of tocilizumab plus MTX, respectively, compared with 41% of patients receiving placebo plus MTX. Statistically significant ACR50 and ACR70 responses were observed in patients receiving combination therapy with either 4 mg/kg or 8 mg/kg of tocilizumab plus MTX (P < 0.05). A dose-related reduction in the Disease Activity Score in 28 joints was observed from week 4 onward, in all patients except those receiving monotherapy with 2 mg/kg of tocilizumab. In the majority of patients who received 8 mg/kg of tocilizumab, the C-reactive protein level/erythrocyte sedimentation rate normalized, while placebo plus MTX had little effect on these laboratory parameters. Tocilizumab was mostly well tolerated, with a safety profile similar to that of other biologic and immunosuppressive therapies. Alanine transaminase and aspartate transaminase levels followed a sawtooth pattern (rising and falling between infusions). There were moderate but reversible increases in the nonfasting total cholesterol and triglyceride levels and reversible reductions in the high-density lipoprotein cholesterol and neutrophil levels. There were 2 cases of sepsis, both of which occurred in patients who were receiving combination therapy with 8 mg/kg of tocilizumab plus MTX. CONCLUSION: These results indicate that targeted blockade of IL-6 signaling is a highly efficacious and promising means of decreasing disease activity in RA.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Metotrexato/uso terapéutico , Receptores de Interleucina-6/antagonistas & inhibidores , Anticuerpos Monoclonales Humanizados , Artritis Reumatoide/fisiopatología , Relación Dosis-Respuesta a Droga , Europa (Continente) , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/epidemiología , Selección de Paciente , Seguridad , Insuficiencia del Tratamiento , Resultado del Tratamiento
13.
Phys Rev Lett ; 96(25): 255501, 2006 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-16907317

RESUMEN

A new extended x-ray-absorption fine structure spectroscopy study of local bonding identifies for the first time significant concentrations of Ge-Ge bonds in amorphous Ge2Sb2Te5. The study provides a new understanding of the local molecular structure of this phase-change material. Application of bond constraint theory indicates that the amorphous phase is an ideal network structure in which the average number of constraints per atom equals the network dimensionality. Analysis within this framework imparts new and significant insights concerning the nature of the reversible optically driven amorphous-crystalline phase transition of Ge2Sb2Te5.

14.
J Dermatol Sci ; 43(2): 85-94, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16797926

RESUMEN

Induction of apoptosis and changes to cytokine secretion patterns have been implicated in the mechanism of action of extracorporeal photopheresis (ECP). Lymphocyte apoptosis is initially detected in significant numbers prior to re-infusion and by 48 h post-ECP the majority of treated lymphocytes are apoptotic. The early apoptosis involves changes to mitochondrial function, reversal of the Bcl-2/Bax ratio and externalisation of phosphatidylserine. Apoptotic lymphocytes, observed from 20 h post-ECP, are associated with enhanced levels of CD95 and Fas-ligand. For cutaneous T cell lymphoma (CTCL), processing of the apoptotic lymphocytes, by suitable antigen presenting cells (APCs), is suggested to induce a clonal cytotoxic response which targets the malignant T cell population. Increased levels of TNFalpha and IFNgamma, observed post-ECP in monocytes and lymphocytes, respectively, are thought to further contribute to the proposed anti-tumour reaction seen in CTCL. However, down-regulation of pro-inflammatory cytokines and enhanced anti-inflammatory responses have been reported following ECP treatment. These immune responses may contribute to the tempering of the inflammatory conditions, such as graft versus host disease, which respond to ECP. Furthermore, untreated monocytes exposed to ECP-treated lymphocytes have also demonstrated a shift in monocyte cytokine-secretory pattern, toward one associated with immune tolerance. Recently, a mechanism of ECP-induced immune tolerance has been linked to the stimulation of the anti-inflammatory cytokines IL10 and TGFbeta by T regulatory cells, following the infusion of ECP-treated CD11c(+) APCs. Ultimately, the multifaceted responses, induced by ECP, may explain the diversity of clinical conditions that benefit.


Asunto(s)
Apoptosis/fisiología , Citocinas/fisiología , Fotoféresis , Humanos , Tolerancia Inmunológica , Inmunidad , Linfocitos/citología , Linfocitos/fisiología
15.
Neuropsychologia ; 44(13): 2700-16, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16455113

RESUMEN

Transcranial magnetic stimulation (TMS) is one of the most recent techniques to have been used in investigations of the parietal cortex but already a number of studies have employed it as a tool in investigations of attentional and sensorimotor processes in the human parietal cortices. The high temporal resolution of TMS has proved to be a particular strength of the technique and the experiments have led to hypotheses about when circumscribed regions of parietal cortex are critical for specific attentional and sensorimotor processes. A consistent theme that runs through many reports is that of a critical contribution of parietal areas when attention or movements are re-directed and representations for attention or action must be updated.


Asunto(s)
Atención/fisiología , Movimiento/fisiología , Lóbulo Parietal/anatomía & histología , Lóbulo Parietal/fisiología , Estimulación Magnética Transcraneal , Animales , Mapeo Encefálico , Humanos , Tiempo de Reacción/fisiología , Factores de Tiempo , Percepción Visual/fisiología
16.
Arthritis Rheum ; 54(1): 47-53, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16385521

RESUMEN

OBJECTIVE: To compare the impact of immediate and delayed introduction of anti-tumor necrosis factor therapy on inflammation and structural damage in methotrexate (MTX)-treated patients with early rheumatoid arthritis (RA). METHODS: Twenty-four patients with erosive early RA (duration < 3 years) who were receiving MTX were randomized to receive infliximab 5 mg/kg or placebo infusions at weeks 0, 2, and 6, and then every 8 weeks through week 46. Beginning at week 54 and thereafter, all patients received infliximab 5 mg/kg. Metacarpophalangeal joints were scanned using high-frequency ultrasonography and power Doppler imaging. Radiographs were evaluated using the modified Sharp/van der Heijde scoring system. RESULTS: From baseline to week 54, total synovial thickness was significantly improved in the infliximab + MTX group compared with the placebo + MTX group (median reduction 95.8% versus 37.5%; P = 0.005), as was the total color Doppler area (CDA; vascularity assessment) (median reduction 100% and 47.1%, respectively; P = 0.025). From week 0 to week 110, no significant between-group difference was observed in the change from baseline for total synovial thickening or the total CDA. At week 54, greater progression in the Sharp/van der Heijde score was apparent in patients receiving placebo + MTX compared with those receiving infliximab + MTX. Although radiographic progression in the placebo + MTX group was greatly reduced in the second year (after initiation of infliximab therapy), marked differences were observed between the infliximab + MTX group (median change in the Sharp/van der Heijde score 4.0) and the placebo + MTX group (median change 14.5) from baseline to week 110 (P = 0.076). CONCLUSION: The results indicate that the efficacy of 2 years of combination therapy with infliximab + MTX for inhibiting cumulative structural damage was superior to that of 1 year of treatment with MTX alone followed by the addition of infliximab.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Antirreumáticos/administración & dosificación , Artritis Reumatoide/tratamiento farmacológico , Metotrexato/administración & dosificación , Artritis Reumatoide/diagnóstico por imagen , Quimioterapia Combinada , Humanos , Infliximab , Radiografía , Factores de Tiempo , Ultrasonografía
17.
Rheumatology (Oxford) ; 44(6): 721-8, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15644394

RESUMEN

Vascular pathology, in the form of angiogenesis, is important in the perpetuation of rheumatoid arthritis (RA) and, in the form of endothelial dysfunction, contributes to associated cardiovascular co-morbidity. Emerging evidence suggests that TNFalpha blockade may modify vascular pathology in RA. Serum concentrations of vascular endothelial growth factor (VEGF), a potent endothelial cell-specific growth factor that is up-regulated by pro-inflammatory cytokines and by hypoxia, are elevated in RA and correlate with disease activity. Serum levels of VEGF at first presentation in RA predict radiographic progression of the disease over the subsequent year. Power Doppler ultrasonography is a sensitive method for demonstrating the presence of blood flow in small vessels and the vascular signal correlates with histopathological quantification of the vascular density of synovial tissue. Recent data indicate that high-frequency ultrasound and power Doppler are sensitive tools for evaluation of disease activity and assessment of response to therapy. Power Doppler imaging may also have the potential to predict those patients most at risk of accelerated joint destruction. However, much work has yet to be done to standardize the use of these imaging technologies.


Asunto(s)
Artritis Reumatoide/sangre , Biomarcadores/sangre , Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/tratamiento farmacológico , Endotelio/fisiopatología , Humanos , Neovascularización Patológica/sangre , Pronóstico , Membrana Sinovial/irrigación sanguínea , Membrana Sinovial/diagnóstico por imagen , Membrana Sinovial/metabolismo , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Ultrasonografía Doppler/métodos , Factores de Crecimiento Endotelial Vascular/sangre
18.
Arthritis Rheum ; 50(4): 1107-16, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15077292

RESUMEN

OBJECTIVE: To investigate sensitive ultrasonographic imaging methods for detection of synovial thickness and vascularity to discriminate between patients with early rheumatoid arthritis (RA) receiving infliximab + methotrexate (MTX) versus placebo + MTX over 18 weeks, and to compare the relationship between synovial thickening and vascularity at baseline and radiologic damage to joints of the hands and feet at 54 weeks. METHODS: Patients with early RA (duration <3 years) receiving stable dosages of MTX were randomly assigned to receive blinded infusions of 5 mg/kg infliximab (n = 12) or placebo (n = 12) at weeks 0, 2, 6, and then every 8 weeks until week 46. At baseline and week 18, clinical assessments were performed, and metacarpophalangeal joints were assessed by high-frequency ultrasonography and power Doppler ultrasonography measurements. Radiographs of the hands and feet taken at baseline and at 54 weeks were evaluated using the van der Heijde modification of the Sharp method (vdH-Sharp score). RESULTS: Using changes in the total vdH-Sharp score over 54 weeks and changes in synovial thickening and joint vascularity at 18 weeks, we were able to distinguish those patients receiving infusions of infliximab + MTX from those receiving placebo + MTX. Sonographic measurements of synovial thickening and vascularity at baseline in the placebo + MTX group demonstrated clear relationships with the magnitude of radiologic joint damage at week 54. Infliximab + MTX treatment abolished these relationships. CONCLUSION: The delay or reversal of inflammatory and joint-destructive mechanisms in patients with early RA was already apparent following 18 weeks of treatment with infliximab + MTX and was reflected in radiologic changes at 54 weeks.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Antirreumáticos/administración & dosificación , Artritis Reumatoide , Sinovitis , Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/tratamiento farmacológico , Artrografía , Proteína C-Reactiva/metabolismo , Método Doble Ciego , Quimioterapia Combinada , Humanos , Infliximab , Articulaciones/irrigación sanguínea , Articulaciones/diagnóstico por imagen , Metotrexato/administración & dosificación , Sinovitis/diagnóstico por imagen , Sinovitis/tratamiento farmacológico , Resultado del Tratamiento , Ultrasonografía
19.
Transplant Proc ; 35(4): 1328-32, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12826151

RESUMEN

UNLABELLED: Immediately following ECP, a significant number of lymphocytes become apoptotic and the number of T cells producing TNFalpha and IFNgamma is reduced. This study sought to determine if the cytokine down-regulation was a direct consequence of apoptosis induction. METHODS: Samples were obtained from 6 graft versus host disease (GvHD) and 5 cutaneous T cell lymphoma (CTCL) patients immediately pre-ECP and from the leucocyte collection bag following 8-MOP/UVA exposure, but prior to re-infusion. Separated peripheral blood mononuclear cells (PBMC) were placed in cell culture and stimulated for 6 hours with phorbol myristate acetate (PMA), Ionomycin and Brefeldin A. Using flow cytometry, T cells were identified by CD3 expression and apoptotic T cells sub-selected by Annexin V staining. Both apoptotic and non-apoptotic T cells were evaluated for their intracellular expression of IL2, IL4, IL10, IFNgamma and TNFalpha. RESULTS: Neither patient group demonstrated a significant change in IL4 or IL10 expression post ECP. However the number of T cells expressing IL2, IFNgamma and TNFalpha was reduced in both the Annexin V-positive and -negative T cell populations (P <.05). The nonapoptotic T cells from GvHD patients demonstrated the greatest reduction in cytokine expression. CONCLUSIONS: Since proinflammatory cytokines play a major role in the pathology of GvHD, their down-regulation post-ECP may produce a direct clinical benefit. The lowest number of IL2-, IFNgamma- and TNFalpha-expressing T cells occurred within the apoptotic population; however, Annexin V-negative T cells also demonstrated a marked reduction post-ECP. However, the lack of an increase in IL4 and IL10 expression indicates that this process was not a consequence of skewing toward a Th2 cytokine profile.


Asunto(s)
Citocinas/sangre , Enfermedad Injerto contra Huésped/terapia , Depleción Linfocítica/métodos , Linfoma Cutáneo de Células T/terapia , Fotoféresis , Linfocitos T/inmunología , Antígenos CD/sangre , Apoptosis , Complejo CD3/sangre , Citometría de Flujo , Humanos , Interleucinas/sangre
20.
J Photochem Photobiol B ; 69(2): 129-38, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12633985

RESUMEN

Following extracorporeal photopheresis (ECP), lymphocytes become apoptotic and upregulate class I MHC antigenic peptides. Conversely, ECP treated monocytes demonstrate activation markers and have an increased avidity for the phagocytosis of apoptotic T cells. Processing of apoptotic T cells by monocytes, following ECP, is thought to induce an immunomodulatory response, which targets untreated, but clonal T cells. Recently we detected apoptotic lymphocytes immediately post ECP. Although enhanced CD95 (Fas) expression has been observed 24 h post ECP, CD95 and Fas-ligand (Fas-L) expression have not been determined at this very early apoptotic stage. Exposure of monocytes to UV has previously suppressed expression of the co-stimulatory molecules required for the presentation of processed antigens to T cells. Our data demonstrate no increase in CD95 or Fas-L expression on T cells tested immediately following ECP. However, the number of T cells expressing Fas-L significantly increased 24 h post ECP (P<0.005). The expression of the co-stimulatory molecules, CD54, CD80 and CD86, remained unaltered on monocytes treated by ECP. Although the mechanism responsible for early induction of lymphocyte apoptosis remains unclear, the later apoptosis involves Fas-L expression. The maintenance of co-stimulatory molecules, on treated monocytes, indicates that they retain the ability to induce an immunomodulatory response.


Asunto(s)
Antígenos CD/metabolismo , Linfoma Cutáneo de Células T/metabolismo , Linfoma Cutáneo de Células T/terapia , Monocitos/metabolismo , Fotoféresis/métodos , Linfocitos T/metabolismo , Antígeno B7-1/metabolismo , Antígeno B7-2 , Células Cultivadas , Humanos , Molécula 1 de Adhesión Intercelular/metabolismo , Linfoma Cutáneo de Células T/sangre , Glicoproteínas de Membrana/metabolismo , Monocitos/efectos de los fármacos , Monocitos/efectos de la radiación , Neoplasias Cutáneas/sangre , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/terapia , Linfocitos T/efectos de los fármacos , Linfocitos T/efectos de la radiación , Células Tumorales Cultivadas , Receptor fas/metabolismo
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