Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic necrotizing vasculitis marked by eosinophilia and extravascular granulomas, predominantly affecting the respiratory tract. This report details a unique EGPA case in a 6-year-old girl with extensive cardiac involvement, featuring an atypical intracardiac mass suggestive of endomyocardial fibrosis and a concomitant thrombus. The clinical course unfolded in three phases: an initial prodrome with asthma; subsequent peripheral hypereosinophilia; and ultimately systemic vasculitis.
View Article and Find Full Text PDFPediatr Rheumatol Online J
June 2024
Background: Many children with rheumatic and musculoskeletal diseases are unrecognized. Identifying these children requires health care provider awareness, knowledge, and skills to recognize disease features and how (and when) to refer to specialist care. The aim of this paper is to highlight the need for better access to health care, review the essential role that education and virtual care play to address unmet need in low resource areas and especially to expand workforce capacity.
View Article and Find Full Text PDFAntibodies can block immune receptor engagement or trigger the receptor machinery to initiate signaling. We hypothesized that antibody agonists trigger signaling by sterically excluding large receptor-type protein tyrosine phosphatases (RPTPs) such as CD45 from sites of receptor engagement. An agonist targeting the costimulatory receptor CD28 produced signals that depended on antibody immobilization and were sensitive to the sizes of the receptor, the RPTPs, and the antibody itself.
View Article and Find Full Text PDFJ Pediatr Pharmacol Ther
October 2023
Objective: Methotrexate is an immunosuppressant commonly used in dermatology. The prevalence of intolerance using the Methotrexate Intolerance Severity Score (MISS) in pediatric juvenile idiopathic arthritis (JIA) ranges from 25% to 75%, but studies in morphea patients are lacking. We sought to determine the prevalence and predictors of methotrexate intolerance in children with morphea compared with children with inflammatory skin diseases and JIA/uveitis.
View Article and Find Full Text PDFA 10-year-old boy with sickle cell disease (SCD) type SC presented with fever and abdominal pain after travel to Ghana and was diagnosed with Plasmodium falciparum infection. Despite adequate antimalarial treatment, he developed evidence of hyperinflammation with marked elevated ferritin, C-reactive protein, and triglycerides and subsequent bone marrow necrosis, characterized by elevated nucleated red blood cells and significant bone pain. This case report highlights the possible association between malaria and bone marrow necrosis in patients with SCD.
View Article and Find Full Text PDFMicroscopy developments since the turn of the decade have seen an abundance of imaging modalities emerge that are revolutionizing the way we image the immune system. We are now able to image faster and utilize techniques that can image individual receptors, in real time, on live T cells. Total internal reflection fluorescence (TIRF) microscopy is one such technique, although it has one problem.
View Article and Find Full Text PDFT cells use finger-like protrusions called 'microvilli' to interrogate their targets, but why they do so is unknown. To form contacts, T cells must overcome the highly charged, barrier-like layer of large molecules forming a target cell's glycocalyx. Here, T cells are observed to use microvilli to breach a model glycocalyx barrier, forming numerous small (<0.
View Article and Find Full Text PDFAngew Chem Weinheim Bergstr Ger
October 2022
Points for accumulation in nanoscale topography (PAINT) allows practically unlimited measurements in localisation microscopy but is limited by background fluorescence at high probe concentrations, especially in volumetric imaging. We present reservoir-PAINT (resPAINT), which combines PAINT and active control of probe photophysics. In resPAINT, an activatable probe "reservoir" accumulates on target, enabling a 50-fold increase in localisation rate versus conventional PAINT, without compromising contrast.
View Article and Find Full Text PDFPoints for accumulation in nanoscale topography (PAINT) allows practically unlimited measurements in localisation microscopy but is limited by background fluorescence at high probe concentrations, especially in volumetric imaging. We present reservoir-PAINT (resPAINT), which combines PAINT and active control of probe photophysics. In resPAINT, an activatable probe "reservoir" accumulates on target, enabling a 50-fold increase in localisation rate versus conventional PAINT, without compromising contrast.
View Article and Find Full Text PDFObjective: 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.
View Article and Find Full Text PDFMuch of what we know about the early stages of T cell activation has been obtained from studies of T cells interacting with glass-supported lipid bilayers that favor imaging but are orders of magnitude stiffer than typical cells. We developed a method for attaching lipid bilayers to polydimethylsiloxane polymer supports, producing "soft bilayers" with physiological levels of mechanical resistance (Young's modulus of 4 kPa). Comparisons of T cell behavior on soft and glass-supported bilayers revealed that whereas late stages of T cell activation are thought to be substrate-stiffness dependent, early calcium signaling was unaffected by substrate rigidity, implying that early steps in T cell receptor triggering are not mechanosensitive.
View Article and Find Full Text PDFvLUME is a virtual reality software package designed to render large three-dimensional single-molecule localization microscopy datasets. vLUME features include visualization, segmentation, bespoke analysis of complex local geometries and exporting features. vLUME can perform complex analysis on real three-dimensional biological samples that would otherwise be impossible by using regular flat-screen visualization programs.
View Article and Find Full Text PDFAvian (chick) embryos are an established and accessible model organism making them ideal for studying developmental processes. Chick embryos can be harvested from the egg and cultured allowing real-time observations and imaging. Here, we describe ex vivo culture and preparation of somite tissue followed by time-lapse multi-photon microscopy, image capture and processing.
View Article and Find Full Text PDFCell-cell contacts often underpin signaling between cells. For immunology, the binding of a T cell receptor to an antigen-presenting pMHC initiates downstream signaling and an immune response. Although this contact is mediated by proteins on both cells creating interfaces with gap sizes typically around 14 nm, many, often contradictory observations have been made regarding the influence of the contact on parameters such as the binding kinetics, spatial distribution, and diffusion of signaling proteins within the contact.
View Article and Find Full Text PDFObjective: Rituximab is an effective treatment for children with steroid dependent or frequently relapsing nephrotic syndrome. The optimum dosing schedule for rituximab has not been established. We hypothesized that a single low dose of 375 mg/m would have comparable outcomes to higher doses in reducing the frequency of relapse and time to B cell reconstitution.
View Article and Find Full Text PDFObjectives: To investigate whether high weight in infancy predicts obesity in childhood.
Method: Data from two UK cohorts (Newcastle Growth and Development N = 795, Gateshead Millennium N = 393) and one Finnish (Tampere N = 1262) were combined. Z scores of weight at 3 and 12 months and body mass index (BMI) at 5 and 8 years were categorized as raised/overweight (1 to <2 SD) or high/obese (≥2 SD).
Clin Otolaryngol
October 2018
Objectives: Endoscopic ear surgery is a rapidly developing field with many advantages. But endoscopes can reach temperatures of over 110°C at the tip, raising safety concerns. Reducing the intensity of the light source reduces temperatures produced.
View Article and Find Full Text PDFAdaptive immune responses are initiated by triggering of the T cell receptor. Single-molecule imaging based on total internal reflection fluorescence microscopy at coverslip/basal cell interfaces is commonly used to study this process. These experiments have suggested, unexpectedly, that the diffusional behavior and organization of signaling proteins and receptors may be constrained before activation.
View Article and Find Full Text PDFSingle-molecule localization microscopy, typically based on total internal reflection illumination, has taken our understanding of protein organization and dynamics in cells beyond the diffraction limit. However, biological systems exist in a complicated three-dimensional environment, which has required the development of new techniques, including the double-helix point spread function (DHPSF), to accurately visualize biological processes. The application of the DHPSF approach has so far been limited to the study of relatively small prokaryotic cells.
View Article and Find Full Text PDFInt J Biol Macromol
February 2017
The kinetic adsorption-desorption behaviour of porcine gastric mucin in the presence of physiologically relevant concentrations of the polyphenol epigallocatechin gallate (EGCG) was investigated using high-resolution kinetic optical waveguide lightmode spectroscopy (OWLS) and atomic force microscopy (AFM). Comparison with dynamic light scattering results from EGCG-mucin mixtures indicates that discrete particles are formed whose size increases with increasing EGCG:mucin ratio. These particles are deduced to be the adsorbing entities, which fuse on the surface to form complex surface layers.
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