Influence of Fine Particulate Dust Particulate Matter 10 on Respiratory Virus Infection in the Republic of Korea

BACKGROUND: This study investigated the effect of fine dust concentrations in the air on the incidence of viral respiratory infections in the Republic of Korea.METHODS: A time series analysis using R statistics was performed to determine the relationship between weekly concentrations of fine dust in the air and the incidences of acute respiratory tract infections caused by the respiratory syncytial virus (RSV), adenovirus (HAdV), rhinovirus (HRV), human metapneumovirus (HMPV), human coronavirus (HCoV), human bocavirus (HBoV), human parainfluenza virus (HPIV), and influenza virus (IFV), from the beginning of 2016 to the end of 2017. Correlations between various meteorological factors and the amount of fine dust were analyzed using the Spearman's rank correlation coefficient. To analyze the relationship between viral infections and fine dust, a quasi-poisson analysis was performed.RESULTS: The incidence of the HAdV was proportional to fine dust and air temperature. The IFV was proportional to fine dust and relative humidity and was inversely proportional to temperature. The HMPV was proportional to fine dust, wind speed, and inversely proportional to relative humidity. The HCoV was proportional to micro dust, relative humidity, and inversely proportional to temperature. Both the HBoV and HPIV were directly proportional to fine dust, temperature, wind speed, and inversely proportional to relative humidity. The RSV was inversely proportional to fine dust, temperature, wind speed. A lag effect was observed for the influenza virus, in that its incidence increased 2–3 weeks later on the cumulative lag model.CONCLUSION: As the weekly average concentration of fine dust increases, the incidence of HAdV, HMPV, HCoV, HBoV, HPIV, and influenza increase.

The Immunomodulatory Activity of Mori folium, the Leaf of Morus alba L., in RAW 264.7 Macrophages In Vitro

BACKGROUND: Immunoregulatory elements have emerged as useful immunotherapeutic agents against cancer. In traditional medicine, Mori folium, the leaf of Morus alba L. (Moraceae), has been used for various medicinal purposes; however, the immunomodulatory effects have not been fully identified. We evaluated the immunoenhancing potential of water extract of Mori folium (WEMF) in murine RAW264.7 macrophages. METHODS: RAW264.7 cells were treated with WEMF for 24 hours and cell viability was detected by an MTT method. Nitric oxide (NO) levels in the culture supernatants were assayed using Griess reagent. The productions of prostaglandin E2 (PGE2) and immune-related cytokines was measured using ELISA detection kits. The mRNA and protein expression levels of Inducible NO synthase, COX-2, and cytokines were assayed by reverse transcription-PCR and Western blotting, respectively. The effect of WEMF on phagocytic activity was measured using a Phagocytosis Assay Kit. RESULTS: WEMF significantly stimulated the production of NO and PGE2 as immune response parameters at noncytotoxic concentrations, which was associated with the increased expression of inducible NO synthase and COX-2. The release and expression of cytokines, such as TNF-α, interleukin (IL)-1β, IL-6, and IL-10, were also significantly increased in response to treatment with WEMF. Moreover, WEMF promoted the macrophagic differentiation of RAW264.7 cells and the resulting phagocytosis activity. CONCLUSIONS: WEMF has the potential to modulate the immune function by regulating immunological parameters. Further studies are needed to identify the active compounds and to support the use of WEMF as an immune stimulant.