Peritoneal cavity cells play pivotal roles in inflammation, repair, and maintaining homeostasis in response to pathogenic infections and tissue injury. Two major tissue-resident macrophages (TRMs) are large peritoneal macrophages (LPMs) and small peritoneal macrophages (SPMs). These are the major macrophage subsets in the peritoneal cavity and originate from embryogenic (LPMs) or bone-marrow-derived myeloid precursors (SPMs). CITE-seq (Cellular Indexing of Transcriptomes and Epitopes by Sequencing) provides simultaneous information for single cells in both cell-surface protein and gene expression levels. Here, we used CITE-seq to profile peritoneal cells by an oligonucleotide-labeled antibody panel designed to react with 189 unique mouse cell surface antigens. We identify 14 markers exclusively expressed on TRMs but not other immune cell types. These markers can classify phenotype differences between LPMs and SPMs during IL-4 stimulation. We further profile fate-mapped TRMs by scRNA-seq and identified more heterogenous phenotypes of TRMs that originated from embryogenic rather than bone-marrow-derived myeloid precursors. Notably, serum amyloid A-3 (Saa3) and platelet factor 4 (Pf4), can distinguish TRM clusters from alternative activation to IL-4 stimulation and Heligmosomoides polygyrus infection. Hence, we identify distinct markers that can be used to distinguish the different origins and heterogenous TRM phenotypes under steady state and type 2 immune responses.

Background: This study explored the application of healthcare failure mode and effect analysis (HFMEA) to identify and evaluate risk-associated factors in the intensive care unit (ICU) through a clinical-based expert knowledge (decision) for the physiological monitor operational maintenance process. Methods and intervention: A mixed qualitative and quantitative proactive approach to explore the HFMEA process by analyzing 20 units of physiological monitors in the ICU. An HFMEA expert team of six people was formed to perform a risk-based analysis and evaluate the potential hazard index, mitigating the hazard scores and risks. Results: From the main processes and possible failure reasons, one high-risk hazard index greater than or equal to 8 of the standard score was found. This standard score indicates the signed manufacturer’s contract for maintenance was the hazard index failure mode on the parts not regularly replaced according to the contract. This systematic hazard index failure mode shows the highest hazard scores in the possible failure reason category, established as a standard maintenance procedure. In addition, the HFMEA expert analysis of the 20 units of physiological monitors within 6 months of the original and remanufactured part maintenance results in operational availability from 90.9% for self-repair to 99.2% for contract manufacturer repair. Conclusions: This study concludes a systematic reference in malpractices caused by maintenance negligence. The HFMEA expert team agrees that hazard failure scores greater than or equal to 8 are vital assessments and evaluations for decision-making, especially in maintaining healthcare intensive unit care physiological monitors.