Risk factors associated with calcinosis of juvenile dermatomyositis

OBJETIVO: Identificar fatores de risco associados à calcinose em crianças e adolescentes com dermatomiosite juvenil. MÉTODOS: Prontuários de 54 pacientes com dermatomiosite juvenil foram estudados. Foram avaliados dados demográficos; características clínicas: grau de força muscular (I a V do Medical Research Council), presença de comprometimentos pulmonar (distúrbio ventilatório restritivo com presença ou ausência do anticorpo anti-Jo-1), gastrointestinal (refluxo gastroesofágico) e cardíaco (pericardite e/ou miocardite); exames laboratoriais: elevação de enzimas musculares (creatinoquinase, aspartato aminotransferase, alanina aminotransferase e desidrogenase lática) e terapias utilizadas: corticoterapia isolada ou associada à cloroquina e/ou imunossupressor. Os pacientes foram divididos em dois grupos de acordo com a presença ou ausência de calcinose e foram avaliados através de análise univariada e multivariada. RESULTADOS: Calcinose foi evidenciada em 23 (43%) pacientes, sendo em seis (26%) antes do diagnóstico e em 17 (74%) após. A análise univariada revelou que comprometimentos cardíaco (p = 0,01) e pulmonar (p = 0,02) e necessidade da utilização de um ou mais imunossupressores (metotrexato, ciclosporina A e/ou pulsoterapia com ciclofosfamida endovenosa) no tratamento da dermatomiosite juvenil (p = 0,03) foram associados com uma maior incidência de calcinose. A análise multivariada mostrou que comprometimento cardíaco (OR = 15,56; IC95% 1,59-152,2) e uso de um ou mais imunossupressores (OR = 4,01; IC95% 1,08-14,87) foram as únicas variáveis independentes associadas à presença de calcinose. CONCLUSÕES: O aparecimento da calcinose foi freqüente na dermatomiosite juvenil, habitualmente na evolução da doença. A calcinose foi associada aos casos mais graves, que apresentaram envolvimento cardíaco e necessitaram da utilização de imunossupressores no seu tratamento.OBJECTIVE: To identify risk factors associated with calcinosis in children and adolescents with juvenile dermatomyositis. METHODS: A review was carried out of the medical records of 54 patients with juvenile dermatomyositis. Data were collected on demographic characteristics, clinical features: muscle strength (stages I to V of the Medical Research Council scale), pulmonary involvement (restrictive pulmonary disease with presence or absence of anti-Jo1 antibodies), gastrointestinal problems (gastroesophageal reflux) and/or heart disease (pericarditis and/or myocarditis); laboratory tests: elevated muscle enzyme levels in serum (creatine phosphokinase, aspartate aminotransferase, alanine aminotransferase and/or lactate dehydrogenase); and on the treatments given: corticoid therapy in isolation or associated with hydroxychloroquine and/or immunosuppressants. The patients were divided into two groups, depending on presence or absence of calcinosis and data were evaluated by both univariate and multivariate analyses. RESULTS: Calcinosis was identified in 23 (43%) patients, and in six (26%) patients it had emerged prior to diagnosis while in 17 (74%) it was post diagnosis. The univariate analysis revealed that cardiac (p = 0.01) and pulmonary (p = 0.02) involvement and the need for one or more immunosuppressor (methotrexate, cyclosporine A and/or pulse therapy with intravenous cyclophosphamide) to treat juvenile dermatomyositis (p = 0.03) were all associated with an increased incidence of calcinosis. The multivariate analysis then demonstrated that only cardiac involvement (OR = 15.56; 95%CI 1.59-152.2) and the use of one or more immunosuppressor (OR = 4.01; 95%CI 1.08-14.87) were independently associated with the presence of calcinosis. CONCLUSIONS: Calcinosis was a frequent development among these juvenile dermatomyositis cases, generally emerging as the disease progressed. Calcinosis was associated with the more severe cases that also had cardiac involvement and where immunosuppressors had to be included in the treatment

Free-flight experiments in LISA Pathfinder

The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors. To accomplish this, the Pathfinder spacecraft will perform drag-free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass. Because the reference test mass is contained within the same spacecraft, it is necessary to apply forces on it to maintain its position and attitude relative to the spacecraft. These forces are a potential source of acceleration noise in the LISA Pathfinder system that are not present in the full LISA configuration. While LISA Pathfinder has been designed to meet it's primary mission requirements in the presence of this noise, recent estimates suggest that the on-orbit performance may be limited by this `suspension noise'. The drift-mode or free-flight experiments provide an opportunity to mitigate this noise source and further characterize the underlying disturbances that are of interest to the designers of LISA-like instruments. This article provides a high-level overview of these experiments and the methods under development to analyze the resulting data.Comment: 13 pages, 5 figures. Accepted to Journal Of Physics, Conference Series. Presented at 10th International LISA Symposium, May 2014, Gainesville, FL, US

In-flight thermal experiments for LISA pathfinder: simulating temperature noise at the inertial sensors

Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations

The LISA pathfinder mission

ISA Pathfinder (LPF), the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future spaceborne gravitational wave detectors, such as the proposed eLISA mission. LISA Pathfinder, and its scientific payload - the LISA Technology Package - will test, in flight, the critical technologies required for low frequency gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra-precise micro-Newton propulsion system. LISA Pathfinder is due to be launched in mid-2015, with first results on the performance of the system being available 6 months thereafter. The paper introduces the LISA Pathfinder mission, followed by an explanation of the physical principles of measurement concept and associated hardware. We then provide a detailed discussion of the LISA Technology Package, including both the inertial sensor and interferometric readout. As we approach the launch of the LISA Pathfinder, the focus of the development is shifting towards the science operations and data analysis - this is described in the final section of the paper