Background: Recently, nicotine administration has been shown to be a potent inhibitor of a variety of innate immune responses, including endotoxin-induced sepsis. Objective: It was the aim of this study to evaluate the effect of nicotine on attenuating lung injury and improving the survival in mice with lipopolysaccharide (LPS)-induced acute lung injury (ALI). Methods: ALI was induced in mice by intratracheal instillation of LPS (3 mg/ml). The mice received intratracheal instillation of nicotine (50, 250 and 500 µg/kg) before or after LPS administration. Pulmonary histological changes were evaluated by hematoxylin-eosin stain, and lung wet/dry weight ratios were observed. Concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and high mobility group box (HMGB)-1, as well as myeloperoxidase (MPO) activity were measured by enzyme-linked immunosorbent assay. The mortality rate was recorded and analyzed by the Kaplan-Meier method. Results: Nicotine pretreatment significantly attenuated the severity of lung injury and inhibited the production of TNF-α, IL-1β and HMGB-1 in mice with ALI. After LPS administration, the lung wet/dry weight ratios, as an index of lung edema, and MPO activity were also markedly reduced by nicotine pretreatment. Early treatment with a high dose of nicotine (500 µg/kg) after LPS administration decreased the mortality in mice with ALI, even when treatment was started 24 h after LPS administration. Conclusion: Nicotine attenuated the lung injury and reduced mortality in mice with LPS-induced ALI.

Objectives. To evaluate the role of short-term low-dose glucocorticoids in mild COVID-19 patients. Methods. We conducted a retrospective, cross-sectional, single-center study in Kunming, China. A total of 33 mild COVID-19 cases were divided into two treatment groups (with and without glucocorticoids, methylprednisolone, were used in this setting), and the absolute value of peripheral blood lymphocyte count; CD3+, CD4+, and CD8+ T cell counts; and the time to achieve negative transformation of a nucleic acid pharyngeal swab were recorded. Peripheral blood lymphocyte and T cell counts were compared between the treatment group and 25 healthy individuals. At the point of time when there was a 50% accumulation conversion rate (positive to negative nucleic acid on pharyngeal swab), and the nucleic acid turned negative in half of the patients in two groups, the peripheral blood lymphocyte and T cell counts were compared between treatment groups. Results. The mean cumulative time for the 50% negative conversion rate of the nucleic acid in the pharyngeal swab was 17.7±5.1 days and 13.9±5.4 days in the glucocorticoid group and the nonglucocorticoid group, respectively. The absolute peripheral blood lymphocyte count and the T cell subset count in the glucocorticoid group were lower than those in the nonglucocorticoid group. When the nucleic acid turned negative in half of the patients, the absolute value of peripheral blood lymphocyte count and CD4+ T cells of the glucocorticoid group and the nonglucocorticoid group was not significantly different; the CD3+ and CD8+ T cells in the glucocorticoid group were lower than those in the nonglucocorticoid group. The absolute peripheral blood lymphocyte count, CD3+ T cells, and CD4+ T cells in the glucocorticoid group were lower than those of the healthy group during the whole disease period, and CD8+ T cells returned to normal at 19-21 days of the disease period. There was no significant difference between the nonglucocorticoid group and the healthy group for absolute peripheral blood lymphocyte and CD8+ T cells; moreover, CD3+ T cells and CD4+ T cells were lower in the nonglucocorticoid group than those in the healthy group from the day of admission to the 18th day and returned to normal at the period of 19-21 days. The absolute peripheral lymphocyte count (P=0.048, effect size d=0.727) and T cell subset count (CD3: P=0.042, effect size d=0.655; CD4: P<0.01, effect size d=0.599; and CD8: P=0.034, effect size d=0.550) in the nonglucocorticoid group were higher than those in the glucocorticoid group, and the difference between the groups was statistically significant. Conclusions. This study found that the use of short-term, low-dose glucocorticoids does not negatively influence the clinical outcome, without affecting the final clearance of viral nucleic acid in mild COVID-19 patients.

Objective: To analyze the clinical characteristics of patients with novel coronavirus pneumonia in Kunming City, and to study the correlation between nutritional status and immune function. Methods: Clinical data of 36 patients with novel coronavirus pneumonia in isolation area of Kunming Third People's Hospital from January 31 to February 15, 2020 were collected, and the basic situation, clinical characteristics, laboratory examination and CT imaging characteristics were analyzed. Serum albumin (ALB), prealbumin (PAB), hypersensitive c-reactive protein (hs-crp), CD3T cells, CD4T cells, CD8T cells and normal control group were analyzed. A simple linear regression analysis of the relationship between proalbumin and T cell subpopulation counts in the blood of patients. Results:(1) The patients with new coronavirus pneumonia in Kunming were mainly of common type. (2) 50% of the patients' first symptoms were fever and cough; (3) The total number of white blood cells in peripheral blood was normal or decreased in 23 cases (79%), and the lymphocyte count decreased in 5 cases (13.89%), without anemia. Hypersensitive c-reactive protein increased in 19 (52.78%) cases, and procalcitonin increased in 1 case. Albumin decreased in 5 cases (13.89%), proalbumin decreased in 15 cases (41.67%), alanine transaminase increased slightly in 4 cases (11.11%), alanine transaminase increased slightly in 4 cases (11.11%), total bilirubin increased slightly in 11 cases (30.56%), and renal function and blood coagulation were normal. Absolute value of CD3 + T cells is with a decrease in 21 cases (58.3%), CD4 + T in 28 cases (77.8%), CD8 + T in 17 cases (47.2%), and CD4 + / CD8 + inverse in 6 cases (16.7%). (4) The prealbumin, CD3 T cells, CD4 T cells and CD8 T cells in the new coronavirus pneumoniagroup were significantly lower than those in the normal control group, and the hypersensitive c-reactive protein was higher than that in the normal control group. (5) The levels of PAB in the serum of the patients were linearly correlated with hs-crp, CD3 T cells, CD4 T cells and CD8 T cells, and the correlation coefficients were -0.474, 0.558, 0.467 and 0.613, respectively, showing statistical differences. Conclusion: The clinical characteristics of the novel coronavirus pneumonia in Kunming are different from those in Wuhan. The changes of serum proalbumin and T cell subsets are relatively obvious. Changes in serum proalbumin may contribute to the early warning of novel coronavirus pneumonia. The nutritional status of patients with common and mild pneumonia should be considered.

To analyse the differential indicators of COVID-19 in severe and mild cases and to study the factors affecting the immune function of patients and the time required for oropharyngeal swabs to become negative. Age, albumin (ALB) levels, prealbumin (PAB) levels, high-sensitivity C-reactive protein (hs-CRP) levels, platelet counts, lymphocyte counts, neutrophil counts, CD3+, CD4+, CD8+ T cell counts and the time for oropharyngeal swabs to become negative were collected from 37 patients with COVID-19; the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were calculated as indicators of inflammation. An independent-sample t test was used to analyse differences between the severe and mild groups, and factors affecting the CD3+, CD4+ and CD8+ T cell counts and the time for the nucleic acid tests of oropharyngeal to convert to negative were identified by single-factor and multifactor analyses. Lymphocyte, ALB, PAB, CD3+, CD4+ and CD8+ T cell levels in the severe group were lower than those in the mild group, the P values were 0.048, 0.004, 0.033, 0.033, 0.015 and 0.013, respectively. The neutrophil count and PLR were higher in the severe group compared with that in the patients of mild group; the P values were all 0.000. Single-factor analysis showed that age, ALB level, PAB level, hs-CRP level, platelet count, the NLR, the PLR and the time to a negative nucleic acid test were the main factors influencing CD3+ T cells; the P values were 0.001, 0.031, 0.001, 0.010, 0.005, 0.002, 0.000 and 0.048, respectively. Age, ALB level, PAB level, hs-CRP level, platelet count, the NLR, the PLR and time to a negative nucleic acid test were the main factors influencing CD8+ T cells; the P values were 0.000, 0.012, 0.000, 0.005, 0.002, 0.004, 0.005 and 0.003, respectively. Age, PAB level, hs-CRP level, platelet count, the NLR and the PLR were the main factors influencing CD4+ T cells; the P values were 0.001, 0.006, 0.030, 0.041, 0.005 and 0.001, respectively. Age, ALB level, PAB level, hs-CRP level, platelet count, the NLR, CD3+ T cell count and CD8+ T cell count were the main factors influencing the time to a negative nucleic acid test in oropharyngeal swabs, and the P values were 0.032, 0.043, 0.013, 0.016, 0.042, 0.049, 0.048 and 0.003, respectively. Multivariate analysis showed that the PLR and platelet count were the main factors influencing CD3+ T cells. The P values were all 0.000. The PLR and platelet count were the main factors influencing CD4+ T cells. The P values were 0.000 and 0.001, respectively. The PLR and platelet count were also the main factors influencing CD8+ T cells. The P values were 0.004 and 0.001. CD8+ T cells affected the time to a negative nucleic acid test in oropharyngeal swab samples, and the P value was 0.002. There were differences in the PLR, PAB level, ALB level and T cells between the severe and mild groups. The platelet count and PLR were the main factors influencing the immune function of patients with COVID-19, and CD8+ T cells influenced the negative conversion time of the nucleic acid test in oropharyngeal swabs.