Collectively, these results demonstrate a novel aspect of UC pathogenesis in which unique IgG plasma cells infiltrate the inflamed mucosa via CXCR4, and critically influence UC pathogenesis by exacerbating mucosal inflammation through the activation of 'pathogenic' intestinal CD14 macrophages via IgG-IC-FcγR signalling.

Presently, COVID-19 is an unprecedented worldwide biohazard, and a nosocomial outbreak can occur in any hospital at any time. Therefore, we reviewed the literature regarding hospital preparedness, the initial management of COVID-19, and the surveillance of healthcare workers (HCWs) to find information that would be generally useful for physicians when confronted with COVID-19. In terms of hospital preparedness, each hospital should develop an incident management system and establish a designated multidisciplinary medical team. To initiate case management, COVID-19 should be suspected based on patient symptoms and/or high-risk history and then should be confirmed by viral testing, such as reverse transcription polymerase chain reaction (RT-PCR) analysis. Although some patients will become critically ill, the guidelines for respiratory failure and septic shock for non-COVID-19 cases can be followed for supportive treatment. Antiviral medications should be carefully selected because the available information is confused by the large volume of preprint literature and unreliable data. HCWs who have come into contact with patients with COVID-19 can generate new in-hospital clusters of COVID-19 cases. Quarantine following contact tracking with risk stratification is effective in preventing transmission, and the essentials of medical surveillance include monitoring different types of symptoms, delegation of supervision, and continuation of surveillance regardless of the RT-PCR results. Preparation for COVID-19 is recommended before the first COVID-19 case is encountered.

Background Some academic organizations recommended that physicians intubate patients with COVID-19 with a relatively lower threshold of oxygen usage particularly in the early phase of pandemic. We aimed to elucidate whether early intubation is associated with decreased in-hospital mortality among patients with novel coronavirus disease 2019 (COVID-19) who required intubation. Methods A multicenter, retrospective, observational study was conducted at 66 hospitals in Japan where patients with moderate-to-severe COVID-19 were treated between January and September 2020. Patients who were diagnosed as COVID-19 with a positive reverse-transcription polymerase chain reaction test and intubated during admission were included. Early intubation was defined as intubation conducted in the setting of ≤ 6 L/min of oxygen usage. In-hospital mortality was compared between patients with early and non-early intubation. Inverse probability weighting analyses with propensity scores were performed to adjust patient demographics, comorbidities, hemodynamic status on admission and time at intubation, medications before intubation, severity of COVID-19, and institution characteristics. Subgroup analyses were conducted on the basis of age, severity of hypoxemia at intubation, and days from admission to intubation. Results Among 412 patients eligible for the study, 110 underwent early intubation. In-hospital mortality was lower in patients with early intubation than those with non-early intubation (18 [16.4%] vs. 88 [29.1%]; odds ratio, 0.48 [95% confidence interval 0.27–0.84]; p = 0.009, and adjusted odds ratio, 0.28 [95% confidence interval 0.19–0.42]; p < 0.001). The beneficial effects of early intubation were observed regardless of age and severity of hypoxemia at time of intubation; however, early intubation was associated with lower in-hospital mortality only among patients who were intubated later than 2 days after admission. Conclusions Early intubation in the setting of ≤ 6 L/min of oxygen usage was associated with decreased in-hospital mortality among patients with COVID-19 who required intubation. Trial Registration None.

Background Rapid deterioration of oxygenation occurs in novel coronavirus disease 2019 (COVID-19), and prediction of mechanical ventilation (MV) is needed for allocation of patients to intensive care unit. Since intubation is usually decided based on varying clinical conditions, such as required oxygen changes, we aimed to elucidate thresholds of increase in oxygen demand to predict MV use within 12 h. Methods A single-center retrospective cohort study using data between January 2020 and January 2021was conducted. Data were retrieved from the hospital data warehouse. Adult patients diagnosed with COVID-19 with a positive polymerase chain reaction (PCR) who needed oxygen during admission were included. Hourly increments in oxygen demand were calculated using two consecutive oxygen values. Covariates were selected from measurements at the closest time points of oxygen data. Prediction of MV use within 12 h by required oxygen changes was evaluated with the area under the receiver operating curves (AUCs). A threshold for increased MV use risk was obtained from restricted cubic spline curves. Results Among 66 eligible patients, 1835 oxygen data were analyzed. The AUC was 0.756 for predicting MV by oxygen demand changes, 0.888 by both amounts and changes in oxygen, and 0.933 by the model adjusted with respiratory rate, PCR quantification cycle (Ct), and days from PCR. The threshold of increments of required oxygen was identified as 0.44 L/min/h and the probability of MV use linearly increased afterward. In subgroup analyses, the threshold was lower (0.25 L/min/h) when tachypnea or frequent respiratory distress existed, whereas it was higher (1.00 L/min/h) when viral load is low (Ct ≥20 or days from PCR >7 days). Conclusions Hourly changes in oxygen demand predicted MV use within 12 h, with a threshold of 0.44 L/min/h. This threshold was lower with an unstable respiratory condition and higher with a low viral load.

Blast injuries caused by an improvised explosive device (IED) are becoming more common in civilian settings. However, physicians may not be familiar with the treatment and management of blast-injured victims. To the best of our knowledge, this is the first case report of a blast injury caused by an IED in Japan.A 64-year-old man was admitted to our hospital's emergency department after sustaining a blast injury. His vital signs were stable, but he had multiple small wounds with embedded foreign bodies that were consistent with injuries sustained by IED victims. The patient was treated for his injuries and was moved to another hospital on day 37. Knowledge about blast injuries caused by IEDs and management strategies for mass casualties are both necessary.