The role of the bone in complex regional pain syndrome 1-A systematic review

OBJECTIVE: The aim of this systematic review was to appraise and analyse the knowledge on bone-related biochemical and histological biomarkers in complex regional pain syndrome 1 (CRPS 1). DATABASE: A total of 7 studies were included in the analysis (biochemical analyses n  = 3, animal study n  = 1, histological examination n  = 3). RESULTS: Two studies were classified as having a low risk of bias and five studies with a moderate risk of bias. Biochemical analysis indicated an increased bone turnover with increased bone resorption (elevated urinary levels of deoxypyridinoline) and bone formation (increased serum levels of calcitonin, osteoprotegerin and alkaline phosphatase). The animal study reported an increased signalling of proinflammatory tumour necrosis factor 4 weeks postfracture, which did, however, not contribute to local bone loss. Histological examination from biopsies revealed thinning and resorption of cortical bone, rarefication and reduction in trabecular bone and vascular modification in the bone marrow in acute CRPS 1, and replacement of the bone marrow by dystrophic vessels in chronic CRPS 1. CONCLUSION: The limited data reviewed revealed certain potential bone-related biomarkers in CRPS. Biomarkers hold the potential to identify patients who may benefit from treatments that influence bone turnover. Thus, this review identifies important areas for future research in CRPS1 patients

Symmetries of perturbed conformal field theories

The symmetries of perturbed conformal field theories are analysed. We explain which generators of the chiral algebras of a bulk theory survive a perturbation by an exactly marginal bulk field. We also study the behaviour of D-branes under current-current bulk deformations. We find that the branes always continue to preserve as much symmetry as they possibly can, i.e. as much as is preserved in the bulk. We illustrate these findings with several examples, including permutation branes in WZW models and B-type D-branes in Gepner models.Comment: 30 pages, 3 figures. V2: Small error in eq. (2.14) correcte

Manifestly Supersymmetric RG Flows

Renormalisation group (RG) equations in two-dimensional N=1 supersymmetric field theories with boundary are studied. It is explained how a manifestly N=1 supersymmetric scheme can be chosen, and within this scheme the RG equations are determined to next-to-leading order. We also use these results to revisit the question of how brane obstructions and lines of marginal stability appear from a world-sheet perspective.Comment: 22 pages; references added, minor change

Association of systemic inflammation with shock severity, 30-day mortality, and therapy response in patients with cardiogenic shock

Background: Mortality in cardiogenic shock (CS) remains high even when mechanical circulatory support (MCS) restores adequate circulation. To detect a potential contribution of systemic inflammation to shock severity, this study determined associations between C-reactive protein (CRP) concentrations and outcomes in patients with CS. Methods: Unselected, consecutive patients with CS and CRP measurements treated at a single large cardiovascular center between 2009 and 2019 were analyzed. Adjusted regression models were fitted to evaluate the association of CRP with shock severity, 30-day in-hospital mortality and treatment response to MCS. Results: The analysis included 1116 patients [median age: 70 (IQR 58–79) years, 795 (71.3%) male, lactate 4.6 (IQR 2.2–9.5) mmol/l, CRP 17 (IQR 5–71) mg/l]. The cause of CS was acute myocardial infarction in 530 (48%) patients, 648 (58%) patients presented with cardiac arrest. Plasma CRP concentrations were equally distributed across shock severities (SCAI stage B–E). Higher CRP concentrations were associated with 30-day in-hospital mortality (8% relative risk increase per 50 mg/l increase in CRP, range 3–13%; p < 0.001), even after adjustment for CS severity and other potential confounders. Higher CRP concentrations were only associated with higher mortality in patients not treated with MCS [hazard ratio (HR) for CRP > median 1.50; 95%-CI 1.21–1.86; p < 0.001], but not in those treated with MCS (HR for CRP > median 0.92; 95%-CI 0.67–1.26; p = 0.59; p-interaction = 0.01). Conclusion: Elevated CRP concentrations are associated with increased 30-day in-hospital mortality in unselected patients with cardiogenic shock. The use of mechanical circulatory support attenuates this association

Renal Function but Not Asymmetric Dimethylarginine Is Independently Associated with Retinopathy in Type 2 Diabetes

Background. Asymmetric dimethylarginine (ADMA) is associated with macrovascular disease and possibly with microangiopathy in type 2 diabetes (T2DM). We tested the hypothesis that ADMA is related to diabetic retinopathy (DR) independently of macrovascular disease. Methods. This cross-sectional study included 127 T2DM patients selected to achieve equal distributions of patients with and without macrovascular disease in the groups with and without DR. Results. Patients with DR had increased ADMA, longer diabetes duration, and reduced glomerular filtration rate (GFR). ADMA correlated with GFR (ρ = -0.35; P < .001), diabetes duration (ρ = 0.19; P = .048), and age (ρ = 0.19; P = .033). Logistic regression analysis revealed an association of ADMA with DR. After adjustment for macrovascular disease, this association remained significant (OR 1.48; 95% CI: 1.02–2.15; P = .039). Inclusion of GFR and T2DM duration into the model abolished this significant relationship. GFR remained the only independent predictor for DR. A 10 mL/min/1.73 m2 GFR decrease was associated with DR in a multivariate model (OR 1.30; 95% CI: 1.08–1.56; P = .006). Conclusions. These findings indicate an association between ADMA and DR in T2DM independent of macrovascular disease. This relationship is modified by GFR, the only parameter significantly related to DR in multivariate analysis

Prospective, randomized, double-blind trial to investigate the efficacy and safety of corneal cross-linking to halt the progression of keratoconus

Background: Corneal cross-linking is widely used to treat keratoconus. However, to date, only limited data from randomized trials support its efficacy. Methods: The efficacy and safety of corneal cross-linking for halting progression of keratoconus were investigated in a prospective, randomized, blinded, placebo controlled, multicentre trial. Twenty-nine keratoconus patients were randomized in three trial centres. The mean age at inclusion was 28 years. Longitudinal changes in corneal refraction were assessed by linear regression. The best corrected visual acuity, surface defects and corneal inflammation were also assessed. These data were analysed with a multifactorial linear regression model. Results: A total of 15 eyes were randomized to the treatment and 14 to the control group. Follow-up averaged 1098 days. Corneal refractive power decreased on average (+/-standard deviation) by 0.35 +/- 0.58 dioptres/year in the treatment group. The controls showed an increase of 0.11 +/- 0.61 dioptres/year. This difference was statistically significant (p = 0.02). Conclusions: Our data suggest that corneal cross-linking is an effective treatment for some patients to halt the progression of keratoconus. However, some of the treated patients still progressed, whereas some untreated controls improved. Therefore, further investigations are necessary to decide which patients require treatment and which do not

Bulk flows in Virasoro minimal models with boundaries

The behaviour of boundary conditions under relevant bulk perturbations is studied for the Virasoro minimal models. In particular, we consider the bulk deformation by the least relevant bulk field which interpolates between the mth and (m-1)st unitary minimal model. In the presence of a boundary this bulk flow induces an RG flow on the boundary, which ensures that the resulting boundary condition is conformal in the (m-1)st model. By combining perturbative RG techniques with insights from defects and results about non-perturbative boundary flows, we determine the endpoint of the flow, i.e. the boundary condition to which an arbitrary boundary condition of the mth theory flows to.Comment: 34 pages, 6 figures. v4: Typo in fig. 2 correcte

Obstructions and lines of marginal stability from the world-sheet

The behaviour of supersymmetric D-branes under deformations of the closed string background is studied using world-sheet methods. We explain how lines of marginal stability and obstructions arise from this point of view. We also show why N=2 B-type branes may be obstructed against (cc) perturbations, but why such obstructions do not occur for N=4 superconformal branes at c=6, i.e. for half-supersymmetric D-branes on K3. Our analysis is based on a field theory approach in superspace, as well as on techniques from perturbed conformal field theory.Comment: 32 page