Melatonin reduces IL-33 and TSLP expression in human nasal epithelial cells by scavenging ROS directly.

BACKGROUND: Chronic rhinosinusitis (CRS) is a chronic mucosal inflammation of the nasal cavity and sinuses. It is classified into CRS without nasal polyps and CRS with nasal polyps (CRSwNP). CRSwNP has high recurrence, especially CRSwNP with massive eosinophil infiltration which is mediated by type 2 inflammatory response. Melatonin is a hormone secreted by the pineal gland, it has powerful antioxidant and anti-inflammatory effects in addition to regulating biological rhythms. There are no studies on melatonin for the treatment of CRS, so we aimed to explore whether melatonin could be used for the treatment of CRS. MATERIALS AND METHODS: In this study, we used melatonin to treat a cell model of CRS. Subsequently, MTT assay was performed to examine the cell viability of human nasal epithelial cells (HNEpCs), a reactive oxygen species (ROS) kit to detect ROS production, a malondialdehyde (MDA) kit to detect the MDA content in the cell culture supernatant, and an apoptosis kit and Western blot analysis to detect apoptosis. The expressions of Nrf2, HO-1, IL-33, TSLP, and IL-25 were detected by Western blot analysis. RESULTS: Melatonin improved the viability of HNEpCs, reduced lipopolysaccharide-induced ROS, reduced the MDA content, and inhibited their apoptosis. More importantly, melatonin reduced the expression of IL-33 and TSLP, an important phenomenon for the treatment of CRSwNP. CONCLUSION: Melatonin protects HNEpCs from damage in inflammation and reduces IL-33 and TSLP expression of HNEpCs.

HO-1: a new marker for predicting postoperative recurrence of CRSwNP.

BACKGROUND: Chronic rhinosinusitis with polyps (CRSwNP) is a subtype of chronic rhinosinusitis and is highly prone to recurrence; therefore, it is urgent to find appropriate markers to predict recurrence of CRSwNP after surgery. PURPOSE: We aim to investigate the expression of HO-1 in CRSwNP and assess its value of predicting postoperative recurrence of CRSwNP. METHODS: We recruited 77 participants and collected clinical data of all. We use Immunohistochemical staining to determine the expression of HO-1 in tissues. We use Spearman correlation test to analyze the correlation between HO-1 positive cell count and clinical score, and ROC curve to assess the value of HO-1 positive cell count in predicting recurrence of CRSwNP. RESULTS: HO-1 positive cells were macrophages and significantly increased in CRSwNP; HO-1 positive cell count was negatively correlated with preoperative SNOT-22 score; HO-1 can predict postoperative recurrence of CRSwNP, AUC = 0.80, p = 0.004. CONCLUSION: HO-1 is a biochemical marker of CRSwNP and can predict postoperative recurrence of CRSwNP.

Hepatitis B virus infection and replication in a new cell culture system established by fusing HepG2 cells with primary human hepatocytes.

BACKGROUND: Hepatitis B virus (HBV) infection is strictly species and tissue specific, therefore none of the cell models established previously can reproduce the natural infection process of HBV in vitro. The aim of this study was to establish a new cell line that is susceptible to HBV and can support the replication of HBV. METHODS: A hybrid cell line was established by fusing primary human hepatocytes with HepG2 cells. The hybrid cells were incubated with HBV-positive serum for 12 hours. HBV DNA was detected by quantitative fluorescence polymerase chain reaction (QF-PCR). HBsAg (surface antigen) and HBeAg (extracellular form of core antigen) were observed by electrochemiluminescence (ECL). HBcAg (core antigen) was detected by the indirect immunofluorescence technique. HBV covalently closed circular DNA (cccDNA) was analyzed by Southern blot hybridization and quantified using real-time PCR. RESULTS: A new cell line was established and named HepCHLine-7. The extracellular HBV DNA was observed from Day 2 and the levels ranged from 9.80 (± 0.32) × 10(2) copies/mL to 3.12 (± 0.03) × 10(4) copies/mL. Intracellular HBV DNA was detected at Day 2 after infection and the levels ranged from 7.92 (± 1.08) × 10(3) copies/mL to 5.63 (± 0.11) × 10(5) copies/mL. HBsAg in the culture medium was detected from Day 4 to Day 20. HBeAg secretion was positive from Day 5 to Day 20. HBcAg constantly showed positive signals in approximately 20% (± 0.82%) of hybrid cells. Intracellular HBV cccDNA could be detected as early as 2 days postinfection and the highest level was 15.76 (± 0.26) copies/cell. CONCLUSION: HepCHLine-7 cells were susceptible to HBV and supported the replication of HBV. They are therefore suitable for studying the complete life cycle of HBV.

[Characteristics of soil organic carbon and enzyme activities in soil aggregates under different vegetation zones on the Loess Plateau].

In order to explore the distribution characteristics of organic carbon of different forms and the active enzymes in soil aggregates with different particle sizes, soil samples were chosen from forest zone, forest-grass zone and grass zone in the Yanhe watershed of Loess Plateau to study the content of organic carbon, easily oxidized carbon, and humus carbon, and the activities of cellulase, ß-D-glucosidase, sucrose, urease and peroxidase, as well as the relations between the soil aggregates carbon and its components with the active soil enzymes were also analyzed. It was showed that the content of organic carbon and its components were in order of forest zone > grass zone > forest-grass zone, and the contents of three forms of organic carbon were the highest in the diameter group of 0.25-2 mm. The content of organic carbon and its components, as well as the activities of soil enzymes were higher in the soil layer of 0-10 cm than those in the 10-20 cm soil layer of different vegetation zones. The activities of cellulase, ß-D-glucosidase, sucrose and urease were in order of forest zone > grass zone > forest-grass zone. The peroxidase activity was in order of forest zone > forest-grass zone > grass zone. The activities of various soil enzymes increased with the decreasing soil particle diameter in the three vegetation zones. The activities of cellulose, peroxidase, sucrose and urease had significant positive correlations with the contents of various forms of organic carbon in the soil aggregates.

The combination of decoy receptor 3 and soluble triggering receptor expressed on myeloid cells-1 for the diagnosis of nosocomial bacterial meningitis.

BACKGROUND: Early diagnosis and appropriate antibiotic treatment can significantly reduce mortality of nosocomial bacterial meningitis. However, it is a challenge for clinicians to make an accurate and rapid diagnosis of bacterial meningitis. This study aimed at determining whether combined biomarkers can provide a useful tool for the diagnosis of bacterial meningitis. METHODS: A retrospective study was carried out. Cerebrospinal fluid (CSF) levels of decoy receptor 3 (DcR3) and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: The patients with bacterial meningitis had significantly elevated levels of the above mentioned biomarkers. The two biomarkers were all risk factors with bacterial meningitis. The biomarkers were constructed into a "bioscore". The discriminative performance of the bioscore was better than that of each biomarker, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.842 (95% confidence intervals (CI) 0.770-0.914; p< 0.001). CONCLUSIONS: Combined measurement of CSF DcR3 and sTREM-1 concentrations improved the prediction of nosocomial bacterial meningitis. The combined strategy is of interest and the validation of that improvement needs further studies.

Predictive value of decoy receptor 3 in postoperative nosocomial bacterial meningitis.

Nosocomial bacterial meningitis requires timely treatment, but what is difficult is the prompt and accurate diagnosis of this disease. The aim of this study was to assess the potential role of decoy receptor 3 (DcR3) levels in the differentiation of bacterial meningitis from non-bacterial meningitis. A total of 123 patients were recruited in this study, among them 80 patients being with bacterial meningitis and 43 patients with non-bacterial meningitis. Bacterial meningitis was confirmed by bacterial culture of cerebrospinal fluid (CSF) culture and enzyme-linked immunosorbent assay (ELISA) was used to detect the level of DcR3 in CSF. CSF levels of DcR3 were statistically significant between patients with bacterial meningitis and those with non-bacterial meningitis (p<0.001). A total of 48.75% of patients with bacterial meningitis received antibiotic>24 h before CSF sampling, which was much higher than that of non-bacterial meningitis. CSF leucocyte count yielded the highest diagnostic value, with an area under the receiver operating characteristic curve (ROC) of 0.928, followed by DcR3. At a critical value of 0.201 ng/mL for DcR3, the sensitivity and specificity were 78.75% and 81.40% respectively. DcR3 in CSF may be a valuable predictor for differentiating patients with bacterial meningitis from those with non-bacterial meningitis. Further studies are needed for the validation of this study.