ObjectiveTo investigate the mechanisms by which Liuwei Buqi prescription （LWBQ） regulates alveolar macrophage efferocytosis and improves inflammatory responses in rats with chronic obstructive pulmonary disease （COPD） characterized by lung-kidney Qi deficiency based on the nuclear factor erythroid 2-related factor 2 （Nrf2）/macrophage receptor with collagenous structure （MARCO） pathway. MethodsSuccessfully modeled rats were randomly divided into a model group， low-dose LWBQ group （LWBQ-L， 2.25 g·kg^-1·d^-1）， medium-dose LWBQ group （LWBQ-M， 4.5 g·kg^-1·d^-1）， high-dose LWBQ group （LWBQ-H， 9 g·kg^-1·d^-1）， and aminophylline group （AMIN， 50 mg·kg^-1·d^-1）， with 8 rats in each group. Another 8 healthy rats were included as the blank group. Except for the blank group， rats in the remaining groups were subjected to smoke exposure combined with forced swimming， intratracheal lipopolysaccharide （LPS） instillation， and subcutaneous hydrocortisone injection to establish a COPD model with lung-kidney Qi deficiency. After successful modeling， rats were administered different doses of LWBQ or AMIN by gavage. Body weight， fur condition， and oral secretions were observed. Pulmonary function was measured using an animal lung function analyzer. Enzyme-linked immunosorbent assay （ELISA） was used to detect the expression levels of interferon-γ （IFN-γ）， interleukin-6 （IL-6）， interleukin-1 （IL-1）， and tumor necrosis factor-α （TNF-α） in bronchoalveolar lavage fluid （BALF） and serum （SER）. Hematoxylin-eosin （HE） staining was used to examine pathological changes in lung tissue. Giemsa staining was performed to detect eosinophils， basophils， and neutrophils in BALF. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL） was used to detect apoptosis in lung tissue. Western blot and real-time polymerase chain reaction （Real-time PCR） were employed to determine the protein and mRNA expression levels of efferocytosis-related proteins growth arrest-specific gene 6 （GAS6）， milk fat globule-epidermal growth factor 8 （MFG-E8）， and pathway-related proteins Nrf2 and MARCO in lung tissue. ResultsCompared with the blank group， the model group showed reduced food intake， nasal and oral secretions with sputum， and decreased body weight （P<0.01）， decreased peak expiratory flow （PEF） （P<0.01）， increased forced vital capacity （FVC） （P<0.01）， and decreased forced expiratory volume in 0.3 s/forced vital capacity ［FEV0.3/FVC （%）］ （P<0.01）. The expression levels of IFN-γ， IL-6， IL-1， and TNF-α in BALF and SER were increased （P<0.01）. Lung tissue exhibited structural destruction， hyperplasia， inflammatory exudation， increased apoptotic cells， and increased mean optical density （P<0.01）. The protein and mRNA expression levels of GAS6， MFG-E8， and MARCO， as well as Nrf2 mRNA expression， were increased （P<0.01）. Compared with the model group， the LWBQ groups showed increased food intake， reduced nasal and oral secretions with sputum， and increased body weight （P<0.05， P<0.01）. PEF was increased （P<0.01）. FVC was increased in rats treated with low- and medium-dose LWBQ （P<0.01）， and FEV0.3/FVC （%） was increased in rats treated with medium- and high-dose LWBQ （P<0.05， P<0.01）. The expression levels of IFN-γ， IL-6， IL-1， and TNF-α in BALF and SER were decreased （P<0.01）. Lung tissue structure was relatively intact， with improvement in hyperplasia and inflammatory exudation. The number of apoptotic cells in lung tissue was reduced， and mean optical density was decreased （P<0.05， P<0.01）. The protein and mRNA expression levels of efferocytosis-related proteins GAS6 and MFG-E8 and pathway-related proteins Nrf2 and MARCO were increased （P<0.01）. ConclusionLWBQ can alleviate pulmonary and systemic inflammation， improve lung function， and reduce lung tissue damage in rats with COPD characterized by lung-kidney Qi deficiency. The mechanism may be related to enhancement of alveolar macrophage efferocytosis through regulation of the Nrf2/MARCO pathway.

Objective:To investigate the effect of R2* value on the evaluation of different degrees of hepatic warm ischemia-reperfusion injury (WIRI) and liver regeneration after partial hepatectomy in rabbits.Methods:Thirty healthy adult male New Zealand White rabbits were randomly divided into five groups. Hepatic caudal lobectomy was performed in both the control and the warm ischemia time-dependent variation group. After reperfusion, routine MRI and BOLD MRI scans were performed for each group at 6 h, 3 d, 7 d, 14 d and 30 d, respectively, and then R2* value and liver regeneration rate (LRR) were measured and calculated. After 30 days of scanning, the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), myeloperoxidase (MPO), tumor necrosis factor - α (TNF - α), interleukin-6 (IL-6) and proliferating cell nuclear antigen (PCNA) were detected in frozen rabbit liver tissues, and the pathological sections were collected. Repeated measures analysis of variance was used to evaluate the changes of R2* value, LRR and its influencing factors at different follow-up time and warm ischemia time in each group. Pearson’s or Spearman’s correlation analysis was used to evaluate the correlation of R2* value with LRR and various biochemical indexes.Results:The interaction between different follow-up time and warm ischemia time ( F = 24.600, P < 0.001) and the single effect of the both on the R2* value had statistically significant difference ( P < 0.05). The interaction of different follow-up time and different warm ischemia time had no effect on LRR, and the difference was not statistically significant ( F = 0.925, P = 0.528), but the difference in the main effect of the both on LRR was statistically significant ( P < 0.05). At the same follow-up time, except for the 40-min ischemia group, the R2* values ??were significantly positively correlated with LRR (3, 7, 14, 30 days after operation, r = 0.510, 0.681, 0.612, 0.541 respectively, P < 0.05). At the same warm ischemia time, the R2* value were significantly negatively correlated with LRR (3, 7, 14, 30 and 40 days after operation, r = - 0.800, -0.852, -0.893, -0.648, -0.853, respectively, P < 0.05). There was no correlation between R2 * value and biochemical indexes at 30 days after operation ( P > 0.05). Conclusion:The R2* value may be used for noninvasive and quantitative evaluation of microstructural changes of WIRI and affect liver regeneration after partial hepatectomy in rabbits. A certain degree of WIRI (≤30 min) after partial hepatectomy can promote liver regeneration in rabbits. Furthermore, as the warm ischemia time prolongs, the promoting effect becomes more pronounced, and if the warm ischemic time exceeds 30 minutes, the promoting effect is significantly reduced.