Model of a Mechanical Clock Escapement

The mechanical tower clock originated in Europe during the 14th century to sound hourly bells and later display hands on a dial. An important innovation was the escapement mechanism, which converts stored energy into oscillatory motion for fixed time intervals through the pendulum swing. Previous work has modeled the escapement mechanism in terms of inelastic and elastic collisions. We derive and experimentally verify a theoretical model in terms of impulsive differential equations for the Graham escapement mechanism in a Seth Thomas tower clock. The model offers insight into the clock’s mechanical behavior and the functionality of the deadbeat escapement mechanism

Racial differences in systemic sclerosis disease presentation: a European Scleroderma Trials and Research group study

Objectives. Racial factors play a significant role in SSc. We evaluated differences in SSc presentations between white patients (WP), Asian patients (AP) and black patients (BP) and analysed the effects of geographical locations.Methods. SSc characteristics of patients from the EUSTAR cohort were cross-sectionally compared across racial groups using survival and multiple logistic regression analyses.Results. The study included 9162 WP, 341 AP and 181 BP. AP developed the first non-RP feature faster than WP but slower than BP. AP were less frequently anti-centromere (ACA; odds ratio (OR) = 0.4, P < 0.001) and more frequently anti-topoisomerase-I autoantibodies (ATA) positive (OR = 1.2, P = 0.068), while BP were less likely to be ACA and ATA positive than were WP [OR(ACA) = 0.3, P < 0.001; OR(ATA) = 0.5, P = 0.020]. AP had less often (OR = 0.7, P = 0.06) and BP more often (OR = 2.7, P < 0.001) diffuse skin involvement than had WP.AP and BP were more likely to have pulmonary hypertension [OR(AP) = 2.6, P < 0.001; OR(BP) = 2.7, P = 0.03 vs WP] and a reduced forced vital capacity [OR(AP) = 2.5, P < 0.001; OR(BP) = 2.4, P < 0.004] than were WP. AP more often had an impaired diffusing capacity of the lung than had BP and WP [OR(AP vs BP) = 1.9, P = 0.038; OR(AP vs WP) = 2.4, P < 0.001]. After RP onset, AP and BP had a higher hazard to die than had WP [hazard ratio (HR) (AP) = 1.6, P = 0.011; HR(BP) = 2.1, P < 0.001].Conclusion. Compared with WP, and mostly independent of geographical location, AP have a faster and earlier disease onset with high prevalences of ATA, pulmonary hypertension and forced vital capacity impairment and higher mortality. BP had the fastest disease onset, a high prevalence of diffuse skin involvement and nominally the highest mortality

Sex influence on outcomes of patients with systemic sclerosis-associated interstitial lung disease: an EUSTAR database analysis

Objective: Interstitial lung disease (ILD) is the leading cause of morbidity/mortality in systemic sclerosis (SSc). We aimed to study investigate the impact of sex on SSc-ILD. Methods: EUSTAR SSc patients with radiological-confirmed ILD and available %predicted forced vital capacity(%pFVC) were included. Demographics and disease features were recorded. Change in %pFVC over 12±6 months (cohort 1) was classified into stable (≤4%), mild (5-9%) and large progression (≥10%). In those with 2-year longitudinal %pFVC (cohort 2), %pFVC change at each 12±6 months interval was calculated. Logistic regression analyses (OR and 95%CI) and Cox proportional hazards models adjusted for age and %pFVC were applied. Results: 1136 male and 5253 female SSc-ILD patients were identified. Males were significantly younger, had a shorter disease duration, higher prevalence of CRP elevation, were had frequently a diffuse cutaneous involvement. In cohort 1(1655 females and 390 males), a higher percentage of males had stable ILD (74.4% versus 69.4%, p = 0.056). In multivariable analysis, disease duration and %pFVC(OR 0.99,0.98-0.99; 0.97,0.95-0.99) in males and age, %pFVC and anti-centromere(OR 1.02,1.00-1.04; 0.97,0.96-0.98; 0.39,0.245-0.63) in females were associated with large progression. The 1-year mortality rate was higher in males (5.1% versus 2.5%, p = 0.013). In cohort 2(849 females and 209 males), a higher percentage of females showed periods of large progression (11.7% versus 7.7%, p = 0.023), the percentage of patients with 0, 1 or 2 periods of worsening was not different. The overall death rate was 30.9% for males and 20.4% in females (p < 0.001). At survival analysis, male sex was a predictor of mortality (OR 1.95, 1.66-2.28). Conclusions: Male SSc-ILD patients have a poorer prognosis and sex-specific predictors exist in SSc-ILD

Progressive interstitial lung disease in patients with systemic sclerosis-associated interstitial lung disease in the EUSTAR database

Objectives To identify overall disease course, progression patterns and risk factors predictive for progressive interstitial lung disease (ILD) in patients with systemic sclerosis-associated ILD (SSc-ILD), using data from the European Scleroderma Trials And Research (EUSTAR) database over long-term follow-up. Methods Eligible patients with SSc-ILD were registered in the EUSTAR database and had measurements of forced vital capacity (FVC) at baseline and after 12±3 months. Long-term progressive ILD and progression patterns were assessed in patients with multiple FVC measurements. Potential predictors of ILD progression were analysed using multivariable mixed-effect models. Results 826 patients with SSc-ILD were included. Over 12±3 months, 219 (27%) showed progressive ILD: either moderate (FVC decline 5% to 10%) or significant (FVC decline >10%). A total of 535 (65%) patients had multiple FVC measurements available over mean 5-year follow-up. In each 12-month period, 23% to 27% of SSc-ILD patients showed progressive ILD, but only a minority of patients showed progression in consecutive periods. Most patients with progressive ILD (58%) had a pattern of slow lung function decline, with more periods of stability/improvement than decline, whereas only 8% showed rapid, continuously declining FVC; 178 (33%) experienced no episode of FVC decline. The strongest predictive factors for FVC decline over 5 years were male sex, higher modified Rodnan skin score and reflux/dysphagia symptoms. Conclusion SSc-ILD shows a heterogeneous and variable disease course, and thus monitoring all patients closely is important. Novel treatment concepts, with treatment initiation before FVC decline occurs, should aim for prevention of progression to avoid irreversible organ damage

Effectiveness and safety of tocilizumab in patients with systemic sclerosis: a propensity score matched controlled observational study of the EUSTAR cohort

Objectives Tocilizumab showed trends for improving skin fibrosis and prevented progression of lung fibrosis in systemic sclerosis (SSc) in randomised controlled clinical trials. We aimed to assess safety and effectiveness of tocilizumab in a real-life setting using the European Scleroderma Trial and Research (EUSTAR) database. Methods Patients with SSc fulfilling the American College of Rheumatology (ACR)/EULAR 2013 classification criteria, with baseline and follow-up visits at 12±3 months, receiving tocilizumab or standard of care as the control group, were selected. Propensity score matching was applied. Primary endpoints were the modified Rodnan skin score (mRSS) and FVC at 12±3 months compared between the groups. Secondary endpoints were the percentage of progressive/regressive patients for skin and lung at 12±3 months. Results Ninety-three patients with SSc treated with tocilizumab and 3180 patients with SSc with standard of care fulfilled the inclusion criteria. Comparison between groups did not show significant differences, but favoured tocilizumab across all predefined primary and secondary endpoints: mRSS was lower in the tocilizumab group (difference -1.0, 95% CI -3.7 to 1.8, p=0.48). Similarly, FVC % predicted was higher in the tocilizumab group (difference 1.5 (-6.1 to 9.1), p=0.70). The percentage of progressive/regressive patients favoured tocilizumab over controls. These results were robust regarding the sensitivity analyses. Safety analysis confirmed previously reported adverse event profiles. Conclusion Although this large, observational, controlled, real-life EUSTAR study did not show significant effectiveness of tocilizumab on skin and lung fibrosis, the consistency of direction of all predefined endpoints generates hypothesis for potential effectiveness in a broader SSc population

Update of EULAR recommendations for the treatment of systemic sclerosis

The aim was to update the 2009 European League against Rheumatism (EULAR) recommendations for the treatment of systemic sclerosis (SSc), with attention to new therapeutic questions. Update of the previous treatment recommendations was performed according to EULAR standard operating procedures. The task force consisted of 32 SSc clinical experts from Europe and the USA, 2 patients nominated by the pan-European patient association for SSc (Federation of European Scleroderma Associations (FESCA)), a clinical epidemiologist and 2 research fellows. All centres from the EULAR Scleroderma Trials and Research group were invited to submit and select clinical questions concerning SSc treatment using a Delphi approach. Accordingly, 46 clinical questions addressing 26 different interventions were selected for systematic literature review. The new recommendations were based on the available evidence and developed in a consensus meeting with clinical experts and patients. The procedure resulted in 16 recommendations being developed (instead of 14 in 2009) that address treatment of several SSc-related organ complications: Raynaud's phenomenon (RP), digital ulcers (DUs), pulmonary arterial hypertension (PAH), skin and lung disease, scleroderma renal crisis and gastrointestinal involvement. Compared with the 2009 recommendations, the 2016 recommendations include phosphodiesterase type 5 (PDE-5) inhibitors for the treatment of SSc-related RP and DUs, riociguat, new aspects for endothelin receptor antagonists, prostacyclin analogues and PDE-5 inhibitors for SSc-related PAH. New recommendations regarding the use of fluoxetine for SSc-related RP and haematopoietic stem cell transplantation for selected patients with rapidly progressive SSc were also added. In addition, several comments regarding other treatments addressed in clinical questions and suggestions for the SSc research agenda were formulated. These updated data-derived and consensus-derived recommendations will help rheumatologists to manage patients with SSc in an evidence-based way. These recommendations also give directions for future clinical research in SSc

Significant weight loss in systemic sclerosis: a study from the EULAR Scleroderma Trials and Research (EUSTAR) database

Gastrointestinal (GI) involvement is almost universal in patients with systemic sclerosis (SSc) and is associated with significant disease-related morbidity and mortality.1 The entire GI tract can be involved and other disease features (eg, low mood, terminal organ failure and functional hand impairment) can result in significant nutritional impairment. Severe GI involvement has been reported to occur in ~10% of patients with SSc and often occurs early in the course of the disease.2 However, identification of patients at high risk of clinically significant weight loss is extremely challenging, including from the high prevalence of GI symptoms in patients with SSc. Therefore, there is a need to understand high-risk patients including potentially modifiable risk factors, with a view to early intervention strategies. Against this background, the aim of this study was to examine potential clinical risk factors of significant weight loss in patients with SSc. We performed an analysis of patients with SSc enrolled in the multinational, longitudinal European League Against Rheumatism (EULAR) Scleroderma Trials and Research (EUSTAR) database. In our study, we defined significant weight loss as 4.5 kg and/or least 5% of their body weight at 5 months onwards.3 Patients with a recorded second visit after 3 months and before 12 months were included in the analysis. We adopted a pragmatic approach (relevant to clinical practice) in

Systemic sclerosis-associated interstitial lung disease in the EUSTAR database: analysis by region

Objectives: The prevalence and characteristics of systemic sclerosis-associated interstitial lung disease (SSc-ILD) vary between geographical regions worldwide. The objectives of this study were to explore the differences in terms of prevalence, phenotype, treatment, and prognosis in patients with SSc-ILD from predetermined geographical regions in the EUSTAR database. Methods: Patients were clustered into seven geographical regions. Clinical characteristics and survival of patients with SSc-ILD were compared among these pre-determined regions. Results: For baseline analyses, 9260 SSc patients were included, with 6732 for survival analyses. The prevalence of SSc-ILD in the overall population was 50.2%, ranging from 44.0% in "Western Europe & Nordic countries" to 67.5% in "Eastern European, Russia & Baltic countries". In all regions, anti-topoisomerase antibodies were associated with SSc-ILD. Management also significantly differed; mycophenolate mofetil was prescribed at baseline in 31.6% of patients with SSc-ILD in "America (North & South)" and 31.7% in "Middle East" but only 4.3% in "Asia & Oceania" (P < 0.0001). Patients from "America (North & South)" and "Middle East" had the highest survival rate at the end of follow-up (85.8% and 85.2%, respectively). Conclusion: Our study highlights key differences among regions in terms of clinical presentation and prognosis of SSc-ILD. This work also demonstrates that the management of SSc-ILD is highly variable among the different regions considered, suggesting that efforts are still needed for the standardisation of medical practice in the treatment of this disease. Keywords: Interstitial lung disease; autoantibodies; lung fibrosis; scleroderma; systemic sclerosis

Health Assessment Questionnaire-Disability Index (HAQ-DI) use in modelling disease progression in diffuse cutaneous systemic sclerosis: an analysis from the EUSTAR database

BACKGROUND: Patients with diffuse cutaneous systemic sclerosis (dcSSc) have a poor prognosis. The importance of monitoring subjective measures of functioning and disability, such as the Health Assessment Questionnaire-Disability Index (HAQ-DI), is important as dcSSc is rated by patients as worse than diabetes or hemodialysis for quality of life impairment. This European Scleroderma Trials and Research (EUSTAR) database analysis was undertaken to examine the importance of impaired functionality in dcSSc prognosis. The primary objectives were to identify predictors of death and HAQ-DI score progression over 1 year. HAQ-DI score, major advanced organ involvement, and death rate were also used to develop a comprehensive model to predict lifetime dcSSc progression. METHODS: This was an observational, longitudinal study in patients with dcSSc registered in EUSTAR. Death and HAQ-DI scores were, respectively, analyzed by Cox regression and linear regression analyses in relation to baseline covariates. A microsimulation Markov model was developed to estimate/predict natural progression of dcSSc over a patient's lifetime. RESULTS: The analysis included dcSSc patients with (N = 690) and without (N = 4132) HAQ-DI score assessments from the EUSTAR database. Baseline HAQ-DI score, corticosteroid treatment, and major advanced organ involvement were predictive of death on multivariable analysis; a 1-point increase in baseline HAQ-DI score multiplied the risk of death by 2.7 (p <  0.001) and multiple advanced major organ involvement multiplied the risk of death by 2.8 (p <  0.05). Multivariable analysis showed that baseline modified Rodnan Skin Score (mRSS) and baseline HAQ-DI score were associated with HAQ-DI score progression at 1 year (p <  0.05), but there was no association between baseline organ involvement and HAQ-DI score progression at 1 year. HAQ-DI score, major advanced organ involvement, and death were successfully used to model long-term disease progression in dcSSc. CONCLUSIONS: HAQ-DI score and major advanced organ involvement were comparable predictors of mortality risk in dcSSc. Baseline mRSS and baseline HAQ-DI score were predictive of HAQ-DI score progression at 1 year, indicating a correlation between these endpoints in monitoring disease progression. It is hoped that this EUSTAR analysis may change physician perception about the importance of the HAQ-DI score in dcSSc