Autoimmunity against the β2 adrenergic receptor and muscarinic-2 receptor in complex regional pain syndrome

Complex regional pain syndrome (CRPS) is a painful condition affecting one or more extremities of the body, marked by a wide variety of symptoms and signs that are often difficult to manage because the pathophysiology is incompletely understood. Thus, diverse treatments might be ineffective. A recent report revealed the presence of autoantibodies against differentiated autonomic neurons in CRPS patients. However, it remained unclear how the antibodies act in the development of CRPS. We therefore aimed to characterize these antibodies and identify target antigens. Functional properties of affinity-purified immunoglobulin G of control subjects or CRPS patients were assessed using a cardiomyocyte bioassay. Putative corresponding receptors were identified using antagonistic drugs, and synthesized peptide sequences corresponding to segments of these receptors were used to identify the target epitopes. Chinese hamster ovary cells were transfected with putative receptors to ensure observed binding. Further, changes in the intracellular Ca²⁺ concentration induced by agonistic immunoglobulin G were measured using the Ca²⁺-sensitive fluorescent dye fura-2 assay. Herein, we demonstrate the presence of autoantibodies in a subset of CRPS patients with agonistic-like properties on the β₂ adrenergic receptor and/or the muscarinic-2 receptor. We identified these autoantibodies as immunoglobulin G directed against peptide sequences from the second extracellular loop of these receptors. The identification of functionally active autoantibodies in serum samples from CRPS patients supports an autoimmune pathogenesis of CRPS. Thus, our findings contribute to the further understanding of this disease, could help in the diagnosis in future, and encourage new treatment strategies focusing on the immune system.     

Interprofessionality as the field of interprofessional practice and interprofessional education: an emerging concept

This paper proposes a new concept and a frame of reference that should permit the development of a better understanding of a phenomenon that is the development of a cohesive and integrated health care practice among professionals in response to clients' needs. The concept is named "interprofessionality" and aims to draw a clear distinction with another concept, that of interdisciplinarity. The utilization of the concept of interdisciplinarity, which originally concerns the development of integrated knowledge in response to fragmented disciplinary knowledge, has caused some confusion. We need a concept that will specifically concern the development of a cohesive practice among different professionals from the same organization or from different organizations and the factors influencing it. There is no concept that focuses clearly on this field. Interprofessionality concerns the processes and determinants that influence interprofessional education initiatives as well as determinants and processes inherent to interprofessional collaboration. Interprofessionality also involves analysis of the linkages between these two spheres of activity. An attempt to bridge the gap between interprofessional education and interprofessional practice is long overdue; the two fields of inquiry need a common basis for analysis. To this end, we propose a frame of reference, an interprofessional education for collaborative patient-centred practice framework. The framework establishes linkages between the determinants and processes of collaboration at several levels, including links among learners, teachers and professionals (micro level), links at the organizational level between teaching and health organizations (meso level) and links among systems such as political, socio-economic and cultural systems (macro level). Research must play a key role in the development of interprofessionality in order to document these linkages and the results of initiatives as they are proposed and implemented. We also believe that interprofessionality will not be pursued without the requisite political will.     

In-Hospital Morbidity and Postoperative Revisions After Direct Anterior vs Posterior Total Hip Arthroplasty

Background

The direct anterior approach (DAA) offers the potential for less soft tissue insult, improved early recovery, and reduced dislocation rates. However, complications are associated with the DAA, particularly during the learning curve. We compare the DAA learning curve experience with the posterior approach regarding in-hospital complications and revision rate.

Lower Extremity Arterial Calcification on Preoperative Knee Radiographs as a Predictor of Postoperative Cardiovascular Events After Primary Total Knee Arthroplasty

Background

A cross-sectional study of total knee arthroplasty (TKA) patients was conducted to determine the association of lower-extremity arterial calcification (LEAC) with acute perioperative cardiovascular events (CVEs).

Antibody‐mediated rejection in pediatric small bowel transplantation: Capillaritis is a major determinant of C4d positivity in intestinal transplant biopsies

The diagnostic criteria for antibody‐mediated rejection (ABMR) after small bowel transplantation (SBT) are not clearly defined, although the presence of donor‐specific antibodies (DSAs) has been reported to be deleterious for graft survival. We aimed to determine the incidence and prognostic value of DSAs and C4d in pediatric SBT and to identify the histopathologic features associated with C4d positivity. We studied all intestinal biopsies (IBx) obtained in the first year posttransplantation (N = 345) in a prospective cohort of 23 children. DSAs and their capacity to fix C1q were identified by using Luminex technology. Eighteen patients (78%) had DSAs, and 9 had the capacity to fix C1q. Seventy‐eight IBx (22.6%) were C4d positive. The independent determinants of C4d positivity were capillaritis grades 2 and 3 (odds ratio [OR] 4.02, P = .047 and OR 5.17, P = .003, respectively), mucosal erosion/ulceration (OR 2.8, P = .019), lamina propria inflammation grades 1 and 2/3 (OR 1.95, P = .043 and OR 3.1, P = .016, respectively), and chorion edema (OR 2.16, P = .028). Complement‐fixing DSAs and repeated C4d‐positive IBx were associated with poor outcome (P = .021 and P = .001, respectively). Our results support that capillaritis should be considered as a feature of ABMR in SBT and identify C1q‐fixing DSAs and repeated C4d positivity as potential markers of poor outcome.     

An apparent Acanthamoeba genotype is the product of a chimeric 18S rDNA artifact

Parasitology Research - Free-living amoebae of the genus Acanthamoeba are potentially pathogenic protozoa widespread in the environment. The detection/diagnosis as well as environmental survey...