Vaporization of perfluorocarbon attenuates sea-water-drowning-induced acute lung injury by deactivating the NLRP3 inflammasomes in canines.

Seawater-drowning-induced acute lung injury (SD-ALI) is a life-threatening disorder characterized by increased alveolar-capillary permeability, an excessive inflammatory response, and refractory hypoxemia. Perfluorocarbons (PFCs) are biocompatible compounds that are chemically and biologically inert and lack toxicity as oxygen carriers, which could reduce lung injury in vitro and in vivo. The aim of our study was to explore whether the vaporization of PFCs could reduce the severity of SD-ALI in canines and investigate the underlying mechanisms. Eighteen beagle dogs were randomly divided into three groups: the seawater drowning (SW), perfluorocarbon (PFC), and control groups. The dogs in the SW group were intratracheally administered seawater to establish the animal model. The dogs in the PFC group were treated with vaporized PFCs. Probe-based confocal laser endomicroscopy (pCLE) was performed at 3 h. The blood gas, volume air index (VAI), pathological changes, and wet-to-dry (W/D) lung tissue ratios were assessed. The expression of heme oxygenase-1 (HO-1), nuclear respiratory factor-1 (NRF1), and NOD-like receptor family pyrin domain containing-3 (NLRP3) inflammasomes was determined by means of quantitative real-time polymerase chain reaction (qRT-PCR) and immunological histological chemistry. The SW group showed higher lung injury scores and W/D ratios, and lower VAI compared to the control group, and treatment with PFCs could reverse the change of lung injury score, W/D ratio and VAI. PFCs deactivated NLRP3 inflammasomes and reduced the release of caspase-1, interleukin-1ß (IL-1ß), and interleukin-18 (IL-18) by enhancing the expression of HO-1 and NRF1. Our results suggest that the vaporization of PFCs could attenuate SD-ALI by deactivating NLRP3 inflammasomes via the HO-1/NRF1 pathway.

Clinical Analysis of Non-AIDS Patients with Pulmonary Cryptococcosis and the Change in Their Clinical Features over 30 Years in a Tertiary Hospital in Beijing, China.

Over the past few decades, the clinical features of pulmonary cryptococcosis (PC) have progressed; however, there is a lack of data on the manifestations of PC over time. To investigate the differences in the clinical characteristics of PC across different time periods, we retrospectively reviewed 130 non-acquired immunodeficiency syndrome (AIDS) patients diagnosed with pathologically or microbiologically confirmed PC from 1990-2020. Among the 130 patients with PC, 24 (18.5%) exhibited immunosuppression, and 44 (33.8%) had underlying diseases. In radiology, 118 (90.8%) presented with subpleural lesions, and 68 (53.1%) presented with nodules with diameters ranging from 1-5 cm. Seventy-five (57.7%) patients underwent surgery alone. The clinical features of PC at different time periods showed that hospitalization days decreased (P = 0.009), and the number of patients with symptoms decreased over time. The number of patients exhibiting isolated lesions decreased (P = 0.022), and the number of patients exhibiting subpleural lesions increased (P = 0.020). In addition, the number of patients with lesions presenting 3-10 mm nodules increased (P = 0.028). In conclusion, an increasing number of patients have been diagnosed with PC over the last 30 years. The timing of PC diagnosis has shifted to the early stages of disease progression. Pulmonary lesions caused by cryptococcosis are easily misdiagnosed and may require unnecessary surgical treatment. Further research is needed to identify the lung lesions caused by cryptococcosis.

The species distribution, antimicrobial resistance and risk factors for poor outcome of coagulase-negative staphylococci bacteraemia in China.

Objective: Coagulase-negative staphylococci (CoNS) are one of the major opportunistic pathogens and the incidence of CoNS bacteraemia is increasing. However, most of the CoNS-positive blood cultures are contaminants rather than true CoNS bacteraemia. In order to minimize contamination, we defined true CoNS bacteraemia as the patient that has two or more identical CoNS-positive blood cultures drawn within 48 h in this study and the objective of this study was to analyse the species distribution and antibiotic resistance and to identify risk factors for 30-day mortality of the true CoNS-bacteraemia. Method: By reviewing the electronic medical database, this study retrospectively analysed patients diagnosed as CoNS bacteraemia by blood cultures in a comprehensive tertiary care hospital in China from January 1, 2014, to December 31, 2017. Result: A total of 1241 patients with 1562 episodes of CoNS-positive blood cultures were recorded in the database but only 157 patients were finally diagnosed as true CoNS bacteraemia after contaminants were excluded. All these 157 patients (12.7%, 157/1241) had bacteraemia-related clinical symptoms. Among the 157 patients, the most common species were Staphylococcus hominis (40.8%), Staphylococcus epidermidis (36.3%) and Staphylococcus capitis (11.5%). The antimicrobial susceptibility tests showed that all CoNS had a high rate of resistance to penicillin (94.9%), oxacillin (93.6%) and erythromycin (92.4%). Resistance to gentamicin (22.3%) and rifampicin (10.8%) was low, and none of the bacteria were resistant to vancomycin or linezolid. The 30-day mortality of patients with CoNS bacteraemia was up to 12.7% (20/157), and the multivariate logistics regression analysis showed that chronic renal failure (OR 5.9, 95% CI 1.6-21.5, p = 0.007) and chronic liver failure (OR 4.0, 95% CI 1.2-13.1, p = 0.024) were both the significant independent risk factors for the 30-day mortality of CoNS bacteraemia. Conclusion: Staphylococcus hominis and Staphylococcus epidermidis were the most common species in CoNS bacteraemia. All CoNS had high multi-drug resistance, but gentamicin and rifampicin had a relatively lower resistance and could be considered as alternative antibiotics for anti-CoNS bacteraemia in addition to vancomycin and linezolid. Additionally, patients with chronic renal failure or chronic liver failure have a higher 30-day mortality after the onset of CoNS bacteraemia.