Elevated Myl9 reflects the Myl9-containing microthrombi in SARS-CoV-2-induced lung exudative vasculitis and predicts COVID-19 severity.

The mortality of coronavirus disease 2019 (COVID-19) is strongly correlated with pulmonary vascular pathology accompanied by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-triggered immune dysregulation and aberrant activation of platelets. We combined histological analyses using field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy analyses of the lungs from autopsy samples and single-cell RNA sequencing of peripheral blood mononuclear cells to investigate the pathogenesis of vasculitis and immunothrombosis in COVID-19. We found that SARS-CoV-2 accumulated in the pulmonary vessels, causing exudative vasculitis accompanied by the emergence of thrombospondin-1-expressing noncanonical monocytes and the formation of myosin light chain 9 (Myl9)-containing microthrombi in the lung of COVID-19 patients with fatal disease. The amount of plasma Myl9 in COVID-19 was correlated with the clinical severity, and measuring plasma Myl9 together with other markers allowed us to predict the severity of the disease more accurately. This study provides detailed insight into the pathogenesis of vasculitis and immunothrombosis, which may lead to optimal medical treatment for COVID-19.

A case of thoracic air leak syndrome with pleural parenchymal fibroelastosis after treatment for hematologic malignancy while awaiting lung transplantation: Imaging and pathological findings of rapid loss in lung volume.

We report the case of a 29-year-old man who underwent umbilical cord blood transplantation for chronic myelogenous leukemia 14 years previously. He was diagnosed with secondary pleuroparenchymal fibroelastosis (sPPFE) following treatment for hematologic malignancies (sPPFE after HM-Tx) 2.5 years ago. On computed tomography, pleural thickening in the upper lobe, lung volume loss, and recurrent bilateral pneumothorax were detected. Although he waited for cadaveric lung transplantation (LTx) for 1.5 years, his respiratory failure worsened, and he died. Pathological autopsy and clinical course indicated sPPFE. After diagnosing sPPFE after HM-Tx, the timing for deciding LTx is critical, especially when pneumothorax recurs.

Sevoflurane-induced pica in female rats.

We examined the effects of volatile anesthetics on pica, which can be used to assess nausea and vomiting in rats. We found that inhalation anesthesia with sevoflurane significantly induced pica in female but not male rats. Among the female rats, young rats (8 weeks old) were more susceptible to its induction than adult rats (20 weeks old) with ovariectomy or sham-surgery. Anti-emetic drugs that are used to prevent postoperative nausea and vomiting (PONV) inhibited the pica. These results suggest that sevoflurane-induced pica in young female rats has the potential to be an animal model of PONV in humans.