RESUMO
BACKGROUND: Multiple listing (ML) is a practice utilized to increase the potential for transplant but is controversial due to concerns that it disproportionately benefits patients with greater access to healthcare resources. RESEARCH QUESTION: Is there disparity in ML practices based on social deprivation in the United States and does ML lead to quicker time to transplant? STUDY DESIGN AND METHODS: A retrospective cohort study of adult (>18 years old) lung transplant candidates listed for transplant (2005-2018) was conducted. Exclusion criteria included heart only or heart and lung transplant and patients relisted during the observation period. Data were obtained from the UNOS Standard Transplant Analysis and Research File. The first exposure of interest was social deprivation index (SDI) with a primary outcome of ML status, to assess disparities between ML and SL participants. The second exposure of interest was ML status with a primary outcome of time to transplant, to assess whether implementation of ML leads to quicker time to transplant. RESULTS: 35,890 subjects were included in the final analysis, of whom 791 (2.2%) were ML and 35,099 (97.8%) were SL. ML participants had lower median level of social deprivation (5 units, more often female (60.0% vs 42.3%), and had lower median LAS (35.3 vs 37.3). ML patients were more likely to be transplanted compared to SL patients (OR=1.42, 95%CI [1.17-1.73]), but there was a significantly quicker time to transplant only for whom ML was early (within 6 months of initial listing) (sHR=1.17, 95%CI [1.04-1.32]). INTERPRETATION: ML is an uncommon practice with disparities existing between ML and SL patients on the basis of several factors including social deprivation. ML patients are more likely to be transplanted, but only if they ML early in their transplant candidacy. With changing allocation guidelines, it is yet to be seen how ML will change with the implementation of continuous distribution.
RESUMO
The extracellular matrix (ECM) is an integral part of multicellular organisms, connecting different cell layers and tissue types. During morphogenesis and growth, tissues undergo substantial reorganization. While it is intuitive that the ECM remodels in concert, little is known regarding how matrix composition and organization change during development. Here, we quantified ECM protein dynamics in the murine forelimb during appendicular musculoskeletal morphogenesis (embryonic days 11.5-14.5) using tissue fractionation, bioorthogonal non-canonical amino acid tagging, and mass spectrometry. Our analyses indicated that ECM protein (matrisome) composition in the embryonic forelimb changed as a function of development and growth, was distinct from other developing organs (brain), and was altered in a model of disease (osteogenesis imperfecta murine). Additionally, the tissue distribution for select matrisome was assessed via immunohistochemistry in the wild-type embryonic and postnatal musculoskeletal system. This resource will guide future research investigating the role of the matrisome during complex tissue development.
