The time course for the activation of glycogen phosphorylase (Phos) and pyruvate dehydrogenase (PDH) and their allosteric regulators was determined in human skeletal muscle during repeated bouts of maximal exercise. Six subjects completed three 30-s bouts of maximal isokinetic cycling separated by 4-min recovery periods. Muscle biopsies were taken at rest and at 6, 15, and 30 s of exercise during bouts 1 and 3. Phos was rapidly activated within the first 6 s of bout 1 from 12% at rest to 47% at 6 s. The activation of PDH increased from 14% at rest to 48% at 6 s and 95% at 15 s of bout 1. Phos reverted back to basal values at the end of the first bout, whereas PDH remained fully activated. In contrast, in the third bout, PDH was 42% at rest and was activated more rapidly and was nearly completely activated by 6 s, whereas Phos remained at basal levels (range 14-20%). Lactate accumulation was marked in the first bout and increased progressively from 2.7 to 76.1 mmol/kg dry wt with no further increase in bout 3. Glycogen utilization was also marked in the first bout and was negligible in bout 3. The rapid activation of Phos and slower activation of PDH in bout 1 was probably due to Ca(2+) release from the sarcoplasmic reticulum. Lactate accumulation appeared to be due to an imbalance of the relative activities of Phos and PDH. The increase in H(+) concentration may have served to reduce pyruvate production by inhibiting Phos transformation and may have simultaneously activated PDH in the third bout such that there was a better matching between pyruvate production and oxidation and minimal lactate accumulation. As each bout progressed and with successive bouts, there was a decreasing ability to stimulate substrate phosphorylation through phosphocreatine hydrolysis and glycolysis and a shift toward greater reliance on oxidative phosphorylation.

During the onset of exercise in hypoxia, the increased lactate accumulation is associated with a delayed activation of pyruvate dehydrogenase (PDH; Parolin ML, Spreit LL, Hultman E, Hollidge-Horvat MG, Jones NL, and Heigenhauser GJF. Am J Physiol Endocrinol Metab 278: E522-E534, 2000). The present study investigated whether activation of PDH with dichloroacetate (DCA) before exercise would reduce lactate accumulation during exercise in acute hypoxia by increasing oxidative phosphorylation. Six subjects cycled on two occasions for 15 min at 55% of their normoxic maximal oxygen uptake after a saline (control) or DCA infusion while breathing 11% O(2). Muscle biopsies of the vastus lateralis were taken at rest and after 1 and 15 min of exercise. DCA increased PDH activity at rest and at 1 min of exercise, resulting in increased acetyl-CoA concentration and acetylcarnitine concentration at rest and at 1 min. In the first minute of exercise, there was a trend toward a lower phosphocreatine (PCr) breakdown with DCA compared with control. Glycogenolysis was lower with DCA, resulting in reduced lactate concentration ([lactate]), despite similar phosphorylase a mole fractions and posttransformational regulators. During the subsequent 14 min of exercise, PDH activity was similar, whereas PCr breakdown and muscle [lactate] were reduced with DCA. Glycogenolysis was lower with DCA, despite similar mole fractions of phosphorylase a, and was due to reduced posttransformational regulators. The results from the present study support the hypothesis that lactate production is due in part to metabolic inertia and cannot solely be explained by an oxygen limitation, even under conditions of acute hypoxia.

To describe the characteristics of patients receiving belimumab, overall patterns of systemic lupus erythematosus (SLE) care, clinical outcomes, and changes in glucocorticoid dose following 6 months of therapy with belimumab, and healthcare resource utilization in belimumab users in Canadian clinical practice settings. Retrospective multicenter medical chart review study of adult patients with SLE who were prescribed belimumab as part of usual care and who received ≥8 infusions or 6 months of treatment. Primary endpoints included physician-determined overall clinical improvement from baseline, glucocorticoid use, and physician-determined SLE disease severity at Month 6. In total, 52 patients were included in the study. At belimumab initiation, 5.8/76.9/17.3% of patients had mild/moderate/severe SLE, respectively. Oral glucocorticoids were discontinued in 11.4% of patients and 59.1% received a lower dose at Month 6. At Month 6, 80.8/57.7/17.3% of patients had a physician-determined clinical improvement of ≥20/≥50/≥80%, respectively. Sixteen patients had a SLE Disease Activity Index-2K score at both baseline and Month 6, with a mean improvement of 2.6 ± 5.3 from 8.1 ± 3.2 at baseline. No formal disease assessment tool was utilized for 42.3% of study patients at baseline. This study provides the first real-world insights into belimumab use in Canada. It demonstrates significant reduction or discontinuation of glucocorticoid dose in 70.5% of patients and clinically significant improvement following 6 months’ belimumab therapy. The high number of patients with no formal disease activity assessments highlights a key care gap in SLE treatment in the real-world setting.

These are considered the first guidelines using the GRADE method for the monitoring of SLE. Existing evidence is largely of low to moderate quality, resulting in more conditional than strong recommendations. Additional rigorous studies and special attention to pediatric SLE populations and patient preferences are needed.

Ultrasound of the hands and/or feet significantly influenced the rheumatologists' diagnostic confidence in specific clinical findings and management plans.

Objective. This study was undertaken to assess the effects of a web-based program, MyLupusGuide, developed to facilitate self-management in systemic lupus erythematosus (SLE).Methods. In this randomized controlled online study, participants received either immediate access to the MyLupusGuide site or delayed access starting on month 3. The primary outcome was the patient activation measure (PAM) score. Secondary outcomes included measurements of health status, self-efficacy, coping, perceived patientphysician relationship, and medication adherence. Outcomes were measured at the baseline visit and at the 3-month and 6-month follow-up visits. We used linear mixed modeling to compare PAM scores between the 2 groups at months 3 and 6.Results. There were 541 participants included in this study. The mean ± SE age was 50 ± 14 years; 93% were female and 74% were White. The mean ± SE disease duration was 17 ± 12 years, and 56% visited MyLupusGuide at least once. The baseline mean ± SE PAM score was 61.2 ± 13, with 36% scoring low for perceived self-management skills. After 3 months of exposure to MyLupusGuide, there were no differences in terms of PAM scores between groups. In exploratory analyses, we found significant improvement in PAM scores in those who had low PAM scores at baseline and in male individuals. We observed significant improvements in self-efficacy before and after access to MyLupusGuide and delayed improvements at month 6 compared to month 3 in terms of mental health and emotional coping.Conclusion. MyLupusGuide increases self-efficacy but not patient activation. A total of 56% of participants visited the MyLupusGuide site during the study period. Individuals with lupus need support to become activated toward self-management behaviors.ClinicalTrials.gov identifier: NCT02950714.

MR imaging of the spine and sacroiliac joints significantly influences the diagnostic confidence of rheumatologists regarding clinical features and overall diagnoses of axial spondyloarthritis, and consequently significantly affects treatment plans.

Objective The transition from pediatric to adult rheumatology care represents a particularly vulnerable time for patients with juvenile idiopathic arthritis (JIA) and childhood‐onset systemic lupus erythematosus (cSLE). Improving self‐management skills is important in optimizing health care transition. The study’s objectives were to 1) examine variability in transition readiness of adolescents and young adults within and between different ages, sexes, and disease types; 2) determine the association between age and transition readiness; and 3) identify specific challenges to transition readiness for adolescents. Methods Over 1 year, patients 14 to 20 years of age with JIA or cSLE were recruited from pediatric transition and young adult clinics at a single academic institution. Participants completed the 14‐item Transition‐Q at a single time point. Total scores range from 0 to 100; higher scores indicate greater health care self‐management skills as a proxy for transition readiness. Descriptive statistics summarized patient characteristics and Transition‐Q scores for the population. Regression analyses determined the association between age, sex, and disease type and Transition‐Q score. Results Among 70 participants, 61 had JIA and 9 cSLE (mean disease duration 4.6 years). The mean (SD) total Transition‐Q score was 59.8 (14.9). Age was significantly associated with Transition‐Q score (standardized β = 0.372l P = 0.002). The most commonly reported challenges were seeing the physician alone (without parents), making one’s own appointments, picking up prescriptions, and independent transportation for appointments. Conclusion Transition readiness appears to increase with patient age. There is significant variability in Transition‐Q scores between patients of the same age, suggesting that an individualized approach to improving self‐management skills is necessary.