This study analyzed the risk factors for patients with COVID-19 developing severe illnesses and explored the value of applying the logistic model combined with ROC curve analysis to predict the risk of severe illnesses at COVID-19 patients’ admissions. The clinical data of 1046 COVID-19 patients admitted to a designated hospital in a certain city from July to September 2020 were retrospectively analyzed, the clinical characteristics of the patients were collected, and a multivariate unconditional logistic regression analysis was used to determine the risk factors for severe illnesses in COVID-19 patients during hospitalization. Based on the analysis results, a prediction model for severe conditions and the ROC curve were constructed, and the predictive value of the model was assessed. Logistic regression analysis showed that age (OR = 3.257, 95% CI 10.466–18.584), complications with chronic obstructive pulmonary disease (OR = 7.337, 95% CI 0.227–87.021), cough (OR = 5517, 95% CI 0.258–65.024), and venous thrombosis (OR = 7322, 95% CI 0.278–95.020) were risk factors for COVID-19 patients developing severe conditions during hospitalization. When complications were not taken into consideration, COVID-19 patients’ ages, number of diseases, and underlying diseases were risk factors influencing the development of severe illnesses. The ROC curve analysis results showed that the AUC that predicted the severity of COVID-19 patients at admission was 0.943, the optimal threshold was −3.24, and the specificity was 0.824, while the sensitivity was 0.827. The changes in the condition of severe COVID-19 patients are related to many factors such as age, clinical symptoms, and underlying diseases. This study has a certain value in predicting COVID-19 patients that develop from mild to severe conditions, and this prediction model is a useful tool in the quick prediction of the changes in patients’ conditions and providing early intervention for those with risk factors.

<b><i>Background:</i></b> The pathogenesis and pulmonary histopathological characteristics of hypersensitivity pneumonitis (HP) are not yet fully understood. Therefore, we established animal models of HP of different stages, aiming to provide support for research on this disease. <b><i>Methods:</i></b> We established rat models of pigeon breeder’s lung of different pathological types by creating freeze-dried allergen powder from fresh pigeon feathers, dander, and other droppings. Freeze-dried allergen powder suspensions of pigeon droppings were used to establish 2 rat models of HP, one by aerosol inhalation and one by airway instillation, and the rats were sacrificed after different lengths of time to observe the pathological changes in their lung tissues. <b><i>Results:</i></b> By the 40th week after allergen inhalation, granulomas were the main changes in the model, without fibrotic changes. When using airway instillation to establish the model, at the 20th week, group 1 (low dose + twice/week) and group 2 (medium dose + twice/week) showed granuloma changes, but no fibrosis; group 3 (high dose + once/week) and group 4 (high dose + twice/week) both showed obvious pulmonary fibrotic changes, but the death rate of rats in group 4 was greater. <b><i>Conclusions:</i></b> Both aerosol inhalation and airway instillation of freeze-dried pigeon allergen powder can successfully establish an HP model. The airway instillation method can cause pulmonary fibrotic changes in a short time, and the pulmonary pathological changes of animal models manifest with an obvious time-dose effect.

This study investigated the molecular mechanisms underlying the involvement of the Notch signaling pathway and autophagy in the development of pulmonary fibrosis in pigeon breeder’s lung (PBL). Rats were divided into control (Ctrl), PBL model (M), M + D (Notch signaling inhibition), M + W (autophagy inhibition), and M + R (autophagy induction) groups. Lyophilized protein powder from pigeon shedding materials was used as an allergen to construct a fibrotic PBL rat model. The mechanism by which Notch signaling regulated autophagy in the pulmonary fibrosis of PBL was investigated by inhibiting the Notch pathway and interfering with autophagy. Pulmonary interstitial fibrosis was significantly greater in the M group and the M + W group than in the M + D and M + R groups. The expression of α-smooth muscle actin was significantly higher in the M, M + D, and M + W groups than in the Ctrl group (P < 0.05). The expression of the cell autophagy markers Beclin1 and LC3 was lower in the M, M + D, and M + W groups than in the Ctrl group (P < 0.05), whereas Beclin1 and LC3 expressions were higher in the M + D and M + R groups than in the M group. The levels of reactive oxygen species in serum and lung tissues were higher in the M, M + D, M + W, and M + R groups than in the Ctrl group (P < 0.05). The Notch signaling pathway is involved in the pathological process of pulmonary fibrosis in the rat model of PBL by regulating autophagy.

<b><i>Introduction:</i></b> We investigated the molecular mechanism by which B lymphocytes regulate Th1/Th2 imbalance to participate in the pulmonary fibrosis in hypersensitivity pneumonia induced by pigeon shedding in rats. <b><i>Methods:</i></b> CD19+ rats and CD19− rats were used to construct animal models of fibrotic hypersensitivity pneumonia. DAPT was used to inhibit the Notch signaling pathway. The pathological changes were assessed with HE and Masson staining. Protein level was detected with Western blot. Th1/Th2 ratio was analyzed with flow cytometry. Cytokine levels were measured with ELISA. <b><i>Results:</i></b> The pathological changes of pulmonary fibrosis were not obvious in the CD19− rats and after DAPT treatment. Notch signaling pathway proteins, including Notch1, Notch2, Jag1, Jag2, DLL1, and DLL4, in lung tissues of model rats were all significantly upregulated than those in control rats. However, these proteins in CD19− rats were lower in CD19+ rats, suggesting that B cells play a key role in inducing pneumonia. Besides, the Th1/Th2 ratio in the BALF of model rats decreased, which was further reversed by DAPT. However, we found that in CD19− rats, the regulation of the Th1/Th2 ratio by the Notch signaling pathway was lost. <b><i>Conclusion:</i></b> Deleting B lymphocytes or blocking the Notch pathway both reversed the Th1/Th2 imbalance in fibrotic hypersensitivity pneumonia and inhibited pulmonary fibrosis.

Background Pulmonary tele-rehabilitation can improve adherence to pulmonary rehabilitation. However, there are few reports on home based pulmonary tele-rehabilitation. We assessed the effectiveness of home based pulmonary tele-rehabilitation under telemedicine system in patients with chronic obstructive pulmonary disease (COPD). Methods This cohort study enrolled 174 patients with COPD who received home based pulmonary tele-rehabilitation under telemedicine system. The follow-up time was 12 weeks. Patients were grouped according to pulmonary rehabilitation weeks, number of rehabilitation times and total duration time, and when these three data were inconsistent, the two lowest values were grouped: control group (total rehabilitation weeks < 1 week, total number of rehabilitation times < 5, total duration time < 150 min, n = 46), pulmonary rehabilitation group 1 (PR-1) (1 week ≤ rehabilitation weeks < 4 weeks, 5 ≤ total number of rehabilitation times < 20, 150 min ≤ total duration time  < 1200 min, n = 31), pulmonary rehabilitation group 2 (PR-2) (4 weeks ≤ rehabilitation weeks < 8 weeks, 20 ≤ total number of rehabilitation times < 40, 600 min ≤ total duration time < 2400 min, n = 23), pulmonary rehabilitation group 3 (PR-3) (8 weeks ≤ rehabilitation weeks < 12 weeks, 40 ≤ total number of rehabilitation times < 60, 1200 min ≤ total duration time < 3600 min, n = 40) and pulmonary rehabilitation group 4 (PR-4) (rehabilitation weeks = 12 weeks, total number of rehabilitation times = 60, total duration time = 3600 min, n = 34). The clinical data before and after rehabilitation were collected and evaluated, including dyspnea symptoms, 6-min walk distance (6MWD), diaphragmatic mobility, anxiety and depression. Results There was no significance difference between control group and PR-1 group. PR-2 group after rehabilitation had significantly decreased CAT and HAMA scores than control (P < 0.05). Compared with control, PR-3 group and PR-4 group after rehabilitation had significantly higher 6MWD and diaphragmatic motility during deep breathing, but significantly lower CAT score, mMRC score, HAMA score, and HAMD score (P < 0.05). Compared with before pulmonary rehabilitation, in PR-3 and PR-4 groups, the 6MWD and the diaphragmatic motility during deep breathing were significantly higher, while CAT score, mMRC score, HAMA score, and HAMD score (for PR-4 only) were significantly lower after pulmonary rehabilitation (P < 0.05). There was no significant difference between PR-3 group and PR-4 group (P > 0.05). In the 12-week pulmonary rehabilitation program, patients who completed at least 8 weeks, namely those in the PR-3 and PR-4 groups, accounted for 42.5% of the total number. Education, income and response rate to telemedicine system reminders were the main risk factors associated with home based pulmonary tele-rehabilitation. Conclusions Home based pulmonary tele-rehabilitation under telemedicine system for more than 8 weeks can significantly improve the dyspnea symptoms, 6MWD, diaphragmatic mobility during deep breathing, and negative emotions of patients with moderate to severe stable COPD. Trial registration: This study was registered at Chinese Clinical Trial Registry under registration number of ChiCTR2200056241CTR2200056241.