Claw-free t-perfect graphs can be recognised in polynomial time

A graph is called t-perfect if its stable set polytope is defined by non-negativity, edge and odd-cycle inequalities. We show that it can be decided in polynomial time whether a given claw-free graph is t-perfect

Modification of a sonographic enthesitis score to differentiate between psoriatic arthritis and young healthy volunteers

Objectives: We aimed to describe sonographic structural and inflammatory changes in entheses of patients with recently diagnosed psoriatic arthritis (PsA), patients with established PsA, and young healthy volunteers, and to investigate whether the MAdrid Sonographic Enthesitis Index (MASEI) enables us to distinguish these groups in an extreme comparison. Method: New and established PsA patients and healthy volunteers (aged 20–30 years) were recruited. The triceps, quadriceps, patellar, Achilles and elbow extensor tendon insertion, and plantar fascia entheses were investigated sonographically for structural changes, erosions, calcifications, increased thickness, bursitis, and power Doppler (PD) signal according to the MASEI. Results: The study included 25 new and 25 established PsA patients, and 25 healthy volunteers. Increased thickness and PD signal in knee entheses were common for patients and healthy volunteers, while changes at other locations predominantly occurred in patients only. PD was recoded (1, one spot; 1.5, two or three spots; 2, confluent signal; 3, severe confluent signal) and thickness of knee entheses excluded. This resulted in different modified MASEI scores between PsA patients and young healthy controls: median (interquartile range) modified MASEI of 13 (10–22.5) in new PsA, 13.5 (9.5–18) in established PsA, and 3 (1–8.5) in healthy volunteers (p = 0.002). Conclusions: Structural ultrasound changes and PD in entheses are common in both new and established PsA and healthy controls. MASEI score did not differentiate PsA patients from young healthy volu

Randomised comparison of initial triple DMARD therapy with methotrexate monotherapy in combination with low-dose glucocorticoid bridging therapy; 1-year data of the tREACH trial

Objectives To compare 1-year clinical efficacy of (1) initial triple disease-modifying antirheumatic drug therapy (iTDT) with initial methotrexate (MTX) monotherapy (iMM) and (2) different glucocorticoid (GC) bridging therapies: oral versus a single intramuscular injection in early rheumatoid arthritis. Methods In a single-blinded randomised clinical trial patients were randomised into three arms: (A) iTDT (methotrexate+sulfasalazine+hydroxychloroquine) with GCs intramuscularly; (B) iTDT with an oral GC tapering scheme and (C) MTX with oral GCs similar to B. Primary outcomes were (1) area under the curve (AUC) of Health Assessment Questionnaire (HAQ) and Disease Activity Score (DAS) and (2) the proportion of patients with radiographic progression. Results 281 patients were randomly assigned to arms A (n=91), B (n=93) or C (n=97). The AUC DAS and HAQ were respectively -2.39 (95% CI -4.77 to -0.00) and -1.67 (95% CI -3.35 to 0.02) lower in patients receiving iTDT than in those receiving iMM. After 3 months, treatment failure occurred less often in the iTDT group, resulting in 40% fewer treatment intensifications. The difference in treatment intensifications between the arms required to maintain the predefined treatment goal remained over time. No differences were seen between the two GC bridging therapies. Respectively 21%, 24% and 23% of patients in arms A, B and C had radiographic progression after 1 year. Patients receiving iTDT had more adjustments of their medication owing to adverse events than those receiving iMM. Conclusions Treatment goals are attained more quickly and maintained with fewer treatment intensifications with iTDT than with iMM. However, no difference in radiographic progression is seen. Both GC bridging therapies are equally effective and, therefore, both can be used

Absence of ultrasound inflammation in patients presenting with arthralgia rules out the development of arthritis

Background: To decrease the burden of disease of rheumatoid arthritis (RA), patients at risk for RA need to be identified as early as possible, preferably when no clinically apparent synovitis can be detected. Up to now, it has been fairly difficult to identify those patients with arthralgia who develop inflammatory arthritis (IA), but recent studies using ultrasound (US) suggest that earlier detection is possible. We aimed to identify patients with arthralgia developing IA within 1year using US to detect subclinical synovitis at first consultation. Methods: In a multi-centre cohort study, we followed patients with arthralgia with at least two painful joints of the hands, feet or shoulders without clinical synovitis over 1year. Symptom duration was<1year, and symptoms were not explained by other conditions. At baseline and at 6 and 12months, data were collected for physical examinations, laboratory values and diagnoses. At baseline, we examined 26 joints ultrasonographically (bilateral metacarpophalangeal joints 2-5, proximal interphalangeal joints 2-5, wrist and metatarsophalangeal joints 2-5). Scoring was done semi-quantitatively on greyscale (GS; 0-3) and power Doppler (PD; 0-3) images. US synovitis was defined as GS≥2 and/or PD≥1. IA was defined as clinical soft tissue swelling. Sensitivity and specificity were used to assess the diagnostic value of US for the development of IA. Univariate logistic regression was used to analyse the association between independent variables and the incidence of IA. For multivariate logistic regression, the strongest variables (p<0.157) were selected. Missing values for independent variables were

Specific MRI abnormalities reveal severe perrault syndrome due to CLPP defects

In establishing a genetic diagnosis in heterogeneous neurological disease, clinical characterization and whole exome sequencing (WES) go hand-in-hand. Clinical data are essential, not only to guide WES variant selection and define the clinical severity of a genetic defect but also to identify other patients with defects in the same gene. In an infant patient with sensorineural hearing loss, psychomotor retardation, and epilepsy, WES resulted in identification of a novel homozygous CLPP frameshift mutation (c.21delA). Based on the gene defect and clinical symptoms, the diagnosis Perrault syndrome type 3 (PRLTS3) was established. The patient's brain-MRI revealed specific abnormalities of the subcortical and deep cerebral white matter and the middle blade of the corpus callosum, which was used to identify similar patients in the Amsterdam brain-MRI database, containing over 3000 unclassified leukoencephalopathy cases. In three unrelated patients with similar MRI abnormalities the CLPP gene was sequenced, and in two of them novel missense mutations were identified together with a large deletion that covered part of the CLPP gene on the other allele. The severe neurological and MRI abnormalities in these young patients were due to the drastic impact of the CLPP mutations, correlating with the variation in clinical manifestations among previously reported patients. Our data show that similarity in brain-MRI patterns can be used to identify novel PRLTS3 patients, especially during early disease stages, when only part of the disease manifestations are present. This seems especially applicable to the severely affected cases in which CLPP function is drastically affected and MRI abnormalities are pronounced

Mixed-integer vertex covers on bipartite graphs

Let $A$ be the edge-node incidence matrix of a bipartite graph \n$G = (U, V ; E)$, $I$ be a subset of the nodes of $G$, and $b$ be a vector such \nthat $2b$ is integral. We consider the following mixed-integer set: \n X(G, b, I) = {x : Ax ≥ b, x ≥ 0, x_i integer for all i ∈ I}. \nWe characterize conv$(X(G, b, I))$ in its original space. That is, we describe a matrix $(C, d)$ such that conv(X(G, b, I)) = {x : Cx ≥ d}. This \nis accomplished by computing the projection onto the space of the $x$-variables of an extended formulation, given in [1], for $conv(X(G, b, I))$. \nWe then give a polynomial-time algorithm for the separation problem for conv$(X(G, b, I))$, thus showing that the problem of optimizing a linear \nfunction over the set $X(G, b, I)$ is solvable in polynomial time. \

Models and algorithms for energy-efficient scheduling with immediate start of jobs

We study a scheduling model with speed scaling for machines and the immediate start requirement for jobs. Speed scaling improves the system performance, but incurs the energy cost. The immediate start condition implies that each job should be started exactly at its release time. Such a condition is typical for modern Cloud computing systems with abundant resources. We consider two cost functions, one that represents the quality of service and the other that corresponds to the cost of running. We demonstrate that the basic scheduling model to minimize the aggregated cost function with n jobs is solvable in O(nlogn) time in the single-machine case and in O(n²m) time in the case of m parallel machines. We also address additional features, e.g., the cost of job rejection or the cost of initiating a machine. In the case of a single machine, we present algorithms for minimizing one of the cost functions subject to an upper bound on the value of the other, as well as for finding a Pareto-optimal solution

Accelerated hand bone mineral density loss is associated with progressive joint damage in hands and feet in recent-onset rheumatoid arthritis

Introduction: To investigate whether accelerated hand bone mineral density (BMD) loss is associated with progressive joint damage in hands and feet in the first year of rheumatoid arthritis (RA) and whether it is an independent predictor of subsequent progressive total joint damage after 4 years. Methods: In 256 recent-onset RA patients, baseline and 1-year hand BMD was measured in metacarpals 2-4 by digital X-ray radiogrammetry. Joint damage in hands and feet were scored in random order according to the Sharp-van der Heijde method at baseline and yearly up to 4 years. Results: 68% of the patients had accelerated hand BMD loss (>-0.003 g/cm(2)) in the first year of RA. Hand BMD loss was associated with progressive joint damage after 1 year both in hands and feet with odds ratios (OR) (95% confidence intervals [CI]) of 5.3 (1.3-20.9) and 3.1 (1.0-9.7). In univariate analysis, hand BMD loss in the first year was a predictor of subsequent progressive total joint damage after 4 years with an OR (95% CI) of 3.1 (1.3-7.6). Multivariate analysis showed that only progressive joint damage in the first year and anti-citrullinated protein antibody positivity were independent predictors of long-term progressive joint damage. Conclusions: In the first year of RA, accelerated hand BMD loss is associated with progressive joint damage in both hands and feet. Hand BMD loss in the first year of recent-onset RA predicts subsequent progressive total joint damage, however not independent of progressive joint damage in the first year.Pathophysiology and treatment of rheumatic disease

Baseline JAK phosphorylation profile of peripheral blood leukocytes, studied by whole blood phosphospecific flow cytometry, is associated with 1-year treatment response in early rheumatoid arthritis

Background: We found recently that baseline signal transducer and activator of transcription 3 phosphorylation in peripheral blood CD4(+) T cells of patients with early rheumatoid arthritis (RA) is associated with treatment response to synthetic disease-modifying antirheumatic drugs (DMARDs). This prompted us to study the baseline phosphorylation profiles of Janus kinases (JAKs) in blood leukocytes with respect to treatment response in early RA. Methods: Thirty-five DMARD-naive patients with early RA provided blood samples for whole blood flow cytometric determination of phosphorylation of JAKs in CD4(+) and CD8(+) T cells, CD19(+) B cells, and CD14(+) monocytes. Treatment response was determined after 1 year of treatment with synthetic DMARDs, with remission defined as absence of tender and swollen joints and normal erythrocyte sedimentation rate. Exact logistic regression was used to investigate the association of baseline variables with treatment response. Ninety-five percent CIs of means were estimated by bias-corrected bootstrapping. Results: High JAK3 phosphorylation in CD4(+) and CD8(+) T cells, CD19(+) B cells, and CD14(+) monocytes and low JAK2 phosphorylation in CD14(+) monocytes were significantly associated with remission following treatment with synthetic DMARDs. Conclusions: Baseline JAK phosphorylation profile in peripheral blood leukocytes may provide a means to predict treatment response achieved by synthetic DMARDs among patients with early RA.Peer reviewe