Characteristics and Outcomes of COVID-19 Survivors Requiring Inpatient Rehabilitation: A Comparison of Two Waves.

OBJECTIVE: Many survivors of severe or critical COVID-19 have required rehabilitation during the pandemic. The primary objective was to compare characteristics and outcomes of survivors of severe or critical COVID-19 admitted to the inpatient rehabilitation facility during the first two waves of the pandemic. Our secondary objective was to identify the factors contributing to functional dependence on admission, discharge, and length of stay. DESIGN: This is a retrospective cohort study of 138 patients admitted to an inpatient rehabilitation facility in two waves after hospitalization for severe or critical COVID-19 illness between April 1, 2020, and May 3, 2021. RESULTS: Inpatient rehabilitation facility patients in wave 2 had significantly greater functional independence (GG scores) on admission (52; interquartile range, 44-58 vs 41; interquartile range, 28-52), lower incidence of dysphagia and anemia. The patients in both waves experienced similar functional improvement efficiencies with a median GG score change of 3.6 per day and similar discharge GG scores. Neurological sequela (odds ratio, 0.12; P < 0.001) and anemia (odds ratio, 1.35; P < 0.002) were identified as independent predictors of functional independence on admission. CONCLUSIONS: Patients with functional deficits after COVID-19 should be considered for acute inpatient rehabilitation as both patient cohorts benefited from their inpatient rehabilitation facility stays with similar length of stays (11-12 days) and discharge to home rates (88%-90%).

Single-cell Transcriptomic Analysis of Salivary Gland Endothelial Cells.

Vascular endothelial cells have important functions in fibrosis via direct and indirect methods and in regeneration through secretion of tissue-specific, paracrineacting angiocrine factors. In the salivary gland, endothelial cells are required for proper development, but their roles within adult glands are largely unknown. The goal of this work was to identify ligand-receptor interactions between endothelial cells and other cell types that are important during homeostasis, fibrosis, and regeneration. To model salivary gland fibrosis and regeneration, we utilized a reversible ductal ligation. To induce injury, a clip was applied to the primary ducts for 14 days, and to induce a regenerative response, the clip was subsequently removed for 5 days. To identify endothelial cell-produced factors, we used single-cell RNA-sequencing of stromal-enriched cells from adult submandibular and sublingual salivary glands. Transcriptional profiles of homeostatic salivary gland endothelial cells were compared to endothelial cells of other organs. Salivary gland endothelial cells were found to express unique genes and displayed the highest overlap in gene expression with other fenestrated endothelial cells from the colon, small intestine, and kidney. Comparison of the 14-day ligated, mock ligated, and 5-day deligated stromal-enriched transcripts and lineage tracing were used to identify evidence for a partial endoMT phenotype, which was observed in a small number of endothelial cell subsets with ligation. CellChat was used to predict changes in ligand-receptor interactions in response to ligation and deligation. CellChat predicted that after ligation, endothelial cells are sources of protein tyrosine phosphatase receptor type m, tumor necrosis factor ligand superfamily member 13, and myelin protein zero signaling and targets for tumor necrosis factor signaling. Following deligation, CellChat predicted that endothelial cells are sources of chemokine (C-X-C motif) and EPH signaling to promote regenerative responses. These studies will inform future endothelial cell-based regenerative therapies.