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The ontogenetic composition of tissue-resident macrophages following injury, environmental exposure, or experimental depletion can be altered upon re-establishment of homeostasis. However, the impact of altered resident macrophage ontogenetic milieu on subsequent immune responses is poorly understood. Hence, we assessed the effect of macrophage ontogeny alteration following return to homeostasis on subsequent allergic airway responses to house dust mites (HDM). Using lineage tracing, we confirmed alveolar and interstitial macrophage ontogeny and their replacement by bone marrow-derived macrophages following LPS exposure. This alteration in macrophage ontogenetic milieu reduced allergic airway responses to HDM challenge. In addition, we defined a distinct population of resident-derived interstitial macrophages expressing allergic airway disease genes, located adjacent to terminal bronchi, and reduced by prior LPS exposure. These findings support that the ontogenetic milieu of pulmonary macrophages is a central factor in allergic airway responses and has implications for how prior environmental exposures impact subsequent immune responses and the development of allergy.

To identify the time at which point of care ultrasound static image recognition and image acquisition skills decay in novice learners.The University of Iowa Hospitals and Clinics.Twenty-four subjects (23 first-year medical students and one first-year physician assistant student).The subjects completed an initial didactic and hands-on session with immediate testing of learned image acquisition and static image identification skills.Retesting occurred at 1, 4, and 8 weeks after the initial training session with no retraining in between. Image acquisition skills were obtained on the same healthy male volunteers, and the students were given no immediate feedback on their performance. The image identification skills were assessed with a 10 question test at each follow-up session.For pleural ultrasound by 4 weeks, there was a significant decline of the ability to identify A-lines (p = 0.0065). For pleural image acquisition, there was no significant decline in the ability to demonstrate lung sliding. Conversely, cardiac image recognition did not significantly decline throughout the study, while the ability to demonstrate cardiac images at 4 weeks (parasternal short axis view) did (p = 0.0008).Motor and cognitive skills decay at different times for pleural and cardiac images. Future ultrasound curricula should retrain skills at a maximum of 8 weeks from initial training. They should focus more on didactic sessions related to image identification for pleural images, and more hands-on image acquisition training for cardiac images, which represents a novel finding.

Hemolytic uremic syndrome (HUS) is a well-described process that is known to cause severe renal dysfunction, thrombocytopenia, and anemia. HUS is typically associated with toxins (shiga-like and shigella toxin) found in strains of E. coli and Shigella spp [1], [2], [3]. We present a case of a 27 year-old man with jaundice, thrombocytopenia, and renal dysfunction who was found to have HUS in the setting of Shigella sonnei infection. Outside of developing countries, cases of HUS related to S. sonnei are largely unreported.