Acute respiratory distress syndrome (ARDS) is difficult to treat and is associated with a high mortality rate. The most severe form of coronavirus disease 2019 (COVID-19) also leads to life-threatening ARDS. Neutrophil counts are positively correlated with disease severity in ARDS. Neutrophil activation not only plays a significant role in immune defense against infections, but also causes tissue damage and leads to inflammatory diseases. Activated neutrophils rapidly migrate to inflamed lung tissue, releasing toxic granular contents and generating neutrophil extracellular traps. In the last few decades, it has become apparent that neutrophils occupy a central role in ARDS pathology. In this review, we summarize the neutrophil inflammatory responses and their relationships to ARDS. According to the current literature, understanding the function of neutrophils may be helpful in the treatment of ARDS.

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Post-transplant malignancy is a major cause of late mortality for liver transplant recipients (LTRs). This nationwide population-based cohort study investigated the cancer type, incidence, and risk factors associated with post-transplant malignancies in 2938 Taiwanese LTRs who underwent transplantation between 1998 and 2012. Data from the National Health Insurance Research Database were extracted on the basis of the International Classification of Disease, Ninth Revision, Clinical Modification codes. Among these patients, 284 post-transplant malignancies were diagnosed. These included 99 de novo malignancies among 98 patients, yielding a standardized incidence ratio of 2.17 (95% CI, 1.76 to 2.64) compared to the general population. The most common malignancies were infection related liver cancer (19.39%), oropharyngeal cancer (19.39%), non-Hodgkin's lymphoma (9.18%), and esophageal cancer (5.10%), as well as non-infection-related prostate cancer (6.12%). Patients with recurrent malignancies had the highest mortality. Furthermore, 186 recurrent malignancies relapsed, and the commonly affected organs were the liver (83.33%), lung (4.84%), bone and bone marrow (4.30%), and intrahepatic bile ducts (2.69%). Old age, the male sex, liver cirrhosis, hepatitis B, peptic ulcer, diabetes mellitus, and pre-existing cancer were all risk factors associated with post-transplant malignancies. Recipients with biliary atresia or urea cycle metabolism disorders were protected from post-transplant malignancies. Our data revealed a significantly increased risk of malignancies in Taiwanese LTRs and suggest implementation of a careful malignancy-surveillance program and immunosuppression-minimizing strategy for high-risk patients.

Phytochemical investigation of the leaves and twigs of and resulted in the isolation of four new triterpenoids (1: -4: ), three triterpenoids (5: -7: ) isolated from a natural source for the first time, and six known compounds (8: -13: ). In addition, four known triterpenoids (14: -17: ) were isolated from . Compound 1: is a 3,4--lupane-type triterpenoid, and compounds 2: -4: are lupane-type triterpenoids in different oxidation states. The structures of all isolated compounds were identified by spectroscopic methods, especially NMR and mass spectrometry data. The absolute configuration of 2: and 3: was confirmed by X-ray single crystallographic analysis. The anti-inflammatory activities of 1: -17: and anti-HIV activities of 2: -17: were evaluated. Among them, 3--betulinic acid (8: ) showed a strong anti-HIV activity comparable to abacavir, a drug used for treating HIV/AIDS. 3,4--4(23),20(29)-lupadiene-3,28-dioic acid (5: ) exhibited potent inhibition of superoxide-anion generation with 86.9 ± 2.8% inhibition at 1 µM.

Background/Aims: Formyl peptide receptors (FPRs) recognize different endogenous and exogenous molecular stimuli and mediate neutrophil activation. Dysregulation of excessive neutrophil activation and the resulting immune responses can induce acute lung injury (ALI) in the host. Accordingly, one promising approach to the treatment of neutrophil-dominated inflammatory diseases involves therapeutic FPR1 inhibition. Methods: We extracted a potent FPR1 antagonist from Garcinia multiflora Champ. (GMC). The inhibitory effects of GMC on superoxide anion release and elastase degranulation from activated human neutrophils were determined with spectrophotometric analysis. Reactive oxygen species (ROS) production and the FPR1 binding ability of neutrophils were assayed by flow cytometry. Signaling transduction mediated by GMC in response to chemoattractants was assessed with a calcium influx assay and western blotting. A lipopolysaccharide (LPS)-induced ALI mouse model was used to determine the therapeutic effects of GMC in vivo. Results: GMC significantly reduced superoxide anion release, the reactive oxidants derived therefrom, and elastase degranulation mediated through selective, competitive FPR1 blocking in N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLF)-stimulated human neutrophils. In cell-free systems, GMC was unable to scavenge superoxide anions or suppress elastase activity. GMC produced a right shift in fMLF-activated concentration-response curves and was confirmed to be a competitive FPR1 antagonist. GMC binds to FPR1 not only in neutrophils, but also FPR1 in neutrophil-like THP-1 and hFPR1-transfected HEK293 cells. Furthermore, the mobilization of calcium and phosphorylation of mitogen-activated protein kinases and Akt, which are involved in FPR1-mediated downstream signaling, was competitively blocked by GMC. In an in vivo study, GMC significantly reduced pulmonary edema, neutrophil infiltration, and alveolar damage in LPS-induced ALI mice. Conclusion: Our findings demonstrate that GMC is a natural competitive FPR1 inhibitor, which makes it a possible anti-inflammatory treatment option for patients critically inflicted with FPR1-mediated neutrophilic lung damage.