Effects of Air Pollution on Chemosensory Dysfunction in COVID-19 Patients.

BACKGROUND: In some patients, coronavirus disease 2019 (COVID-19) is accompanied by loss of smell and taste, and this has been reportedly associated with exposure to air pollutants. This study investigated the relationship between the occurrence of chemosensory dysfunction in COVID-19 patients and air pollutant concentrations in Korea. METHODS: Information on the clinical symptom of chemosensory dysfunction, the date of diagnosis, residential area, age, and sex of 60,194 confirmed COVID-19 cases reported to the Korea Disease Control and Prevention Agency from January 20 to December 31, 2020 was collected. In addition, the daily average concentration of air pollutants for a week in the patients' residential area was collected from the Ministry of Environment based on the date of diagnosis of COVID-19. A binomial logistic regression model, using age and gender, standardized smoking rate, number of outpatient visits, 24-hour mean temperature and relative humidity at the regional level as covariates, was used to determine the effect of air pollution on chemosensory dysfunction. RESULTS: Symptoms of chemosensory dysfunction were most frequent among patients in their 20s and 30s, and occurred more frequently in large cities. The logistic analysis showed that the concentration of particulate matter 10 (PM10) and 2.5 (PM2.5) up to 2 days before the diagnosis of COVID-19 and the concentration of sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) at least 7 days before the diagnosis of COVID-19 affected the development of chemosensory dysfunction. In the logistic regression model adjusted for age, sex, standardized smoking rate, number of outpatient visits, and daily average temperature and relative humidity, it was found that an increase in the interquartile range of PM10, PM2.5, SO2, NO2, and CO on the day of diagnosis increased the incidence of chemosensory dysfunction 1.10, 1.10, 1.17, 1.31, and 1.19-fold, respectively. In contrast, the O3 concentration had a negative association with chemosensory dysfunction. CONCLUSION: High concentrations of air pollutants such as PM10, PM2.5, SO2, NO2, and CO on the day of diagnosis increased the risk of developing chemosensory dysfunction from COVID-19 infection. This result underscores the need to actively prevent exposure to air pollution and prevent COVID-19 infection. In addition, policies that regulate activities and products that create high amounts of harmful environmental wastes may help in promoting better health for all during COVID-19 pandemic.

Effect of immobilized cell-binding peptides on chitosan membranes for osteoblastic differentiation of mesenchymal stem cells.

Two cell-binding domains from FGF-2 (fibroblast growth factor-2) were shown to increase cell attachment and osteoblastic differentiation. Two synthetic peptides derived from FGF-2, namely residues 36-41 (F36; PDGRVD) and 77-83 (F77; KEDGRLL), were prepared and their N-termini further modified for ease of surface immobilization. Chitosan membranes were used in the present study as mechanical supportive biomaterials for peptide immobilization. Peptides could be stably immobilized on to the surface of chitosan membranes. The adhesion of mesenchymal stem cells to the peptide (F36 and F77)-immobilized chitosan membrane was increased in a dose-dependent manner and completely inhibited by soluble RGD (Arg-Gly-Asp) and anti-integrin antibody, indicating the existence of an interaction between F36/F77 and integrin. Peptide-immobilized chitosan supported human bone-marrow-derived mesenchymal-stem-cell differentiation into osteoblastic cells, as demonstrated by alkaline phosphate expression and mineralization. Taken together, the identified peptide-immobilized chitosan membranes were able to support cell adhesion and osteoblastic differentiation; thus these peptides might be useful as bioactive agents for osteoblastic differentiation and surface-modification tools in bone regenerative therapy.

Differences in circulating dendritic cell subtypes in pregnant women, cord blood and healthy adult women.

Different subtypes of dendritic cells (DC) influence the differentiation of naíve T lymphocytes into T helper type 1 (Th1) and Th2 effector cells. We evaluated the percentages of DC subtypes in peripheral blood from pregnant women (maternal blood) and their cord blood compared to the peripheral blood of healthy non pregnant women (control). Circulating DC were identified by flow cytometry as lineage (CD3, CD14, CD16, CD19, CD20, and CD56)-negative and HLA-DR-positive cells. Subtypes of DC were further characterized as myeloid DC (CD11c(+)/CD123(+/-)), lymphoid DC (CD11c(-)/CD123(+++)) and less differentiated DC (CD11c(-)/CD123(+/-)). The frequency of DC out of all nucleated cells was significantly lower in maternal blood than in control (P<0.001). The ratio of myeloid DC/lymphoid DC was significantly higher in maternal blood than in control (P<0.01). HLA-DR expressions of myeloid DC as mean fluorescence intensity (MFI) were significantly less in maternal blood and in cord blood than in control (P<0.001, respectively). The DC differentiation factors, TNF-alpha and GM-CSF, released from mononuclear cells after lipopolysaccharide stimulation were significantly lower in maternal blood than in control (P<0.01). The distribution of DC subtypes was different in maternal and cord blood from those of non-pregnant women. Their role during pregnancy remains to be determined.

Characterization of the surface immobilized synthetic heparin binding domain derived from human fibroblast growth factor-2 and its effect on osteoblast differentiation.

Fibroblast growth factor (FGF)-2 regulates a variety of cellular functions, such as proliferation and differentiation, by binding to cell surface FGF receptors (FGFRs) in the presence of heparin proteoglycans. FGF-2 is known as a heparin-binding growth factor, but the localization of the heparin binding site has not been fully investigated until now. We used two potential heparin binding domains of FGF-2, the residues 105-111 (F105, YKRSRYT) and 119-135 (F119, KRTGQYKLGSKTGPGQK). Peptides could be stably immobilized onto the surface of tissue culture plates. Using solid phase binding assays, we demonstrated that both peptides had higher binding affinity toward heparin compared with nonbinding control sequence. The biological significance of these sites was tested by cell attachment and osteoblast differentiation studies. Cell attachment to the peptides F105 and F119 increased in a dose-dependent manner. Heparin and heparinase treatments decreased cell adhesion to both F105 and F119. This demonstrates that both F105 and F119 interact with cell-surface heparan sulfate proteoglycans, suggesting that FGF-2 has two heparin binding sites. In addition, osteoblast differentiation, confirmed by ALPase activity and mineralization, was increased by surface immobilized peptide F105 and F119. Taken together, these heparin binding peptides could be applied as biological agents enhancing osteoblast differentiation as well as surface modification tools in the tissue regeneration area, especially for bone regeneration.

[Family experiences of living with chronic schizophrenic patients - application of Parse's human becoming research methodology].

PURPOSE: This study was aimed at understanding the nature of the suffering of families with patients in mental health nursing homes and hoped to contribute to the rehabilitation process of those with a chronic mental disorder. METHOD: Research methodology was based upon Parse's human becoming research methodology. RESULTS: a) Despite the despair the family feels by the violence caused by their now-institutionalized relative, they also realize anew the importance of their role as protectors b) Although they fear social stigmatization they also try to be supportive, out of guilt feelings; c) They regret their severe rearing style and wish to be more sympathetic, d) They find courage and hope through family therapy, which leads to a better understanding of the illness, e) With hopes of rehabilitation, the family members feel happy and go through an emotional release, by sharing the pain with each other. CONCLUSION: Families of nursing home residents share a focus on the process of human-health-universe. This is a positive, 'human-becoming' process with which, based on past feelings of despair, fear, resignation, and pain, one can render meaning into his or her experiences in the present in the pursuit of love, conquest, hope, liberty and success.

Fucoidan Extracted from Hijiki Protects Brain Microvessel Endothelial Cells Against Diesel Exhaust Particle Exposure-Induced Disruption.

This study was performed to evaluate the protective effects of fucoidan against the decreased function of primary cultured bovine brain microvessel endothelial cells (BBMECs) after exposure to diesel exhaust particles (DEPs). BBMECs were extracted from bovine brains and cultured until confluent. To evaluate the function of BBMECs, we performed a permeability test using cell-by-cell equipment and by Western blot analysis for zonular occludens-1 (ZO-1), which is a tight junction protein of BMECs, and evaluated oxidative stress in BBMECs using the DCFH-DA assay and the CUPRAC-BCS assay. The increased oxidative stress in BBMECs following DEP exposure was suppressed by fucoidan. In addition, permeability of BBMECs induced by DEP exposure was decreased by fucoidan treatment. Our results showed that fucoidan protects against BBMEC disruption induced by DEP exposure. This study provides evidence that fucoidan might protect the central nervous system (CNS) against DEP exposure.

Effects of ultrafine diesel exhaust particles on oxidative stress generation and dopamine metabolism in PC-12 cells.

A major constituent of urban air pollution is diesel exhaust, a complex mixture of gases, chemicals, and particles. Recent evidence suggests that exposure to air pollution can increase the risk of a fatal stroke, cause cerebrovascular damage, and induce neuroinflammation and oxidative stress that may trigger neurodegenerative diseases, such as Parkinson's disease. The specific aim of this study was to determine whether ultrafine diesel exhaust particles (DEPs), the particle component of exhaust from diesel engines, can induce oxidative stress and effect dopamine metabolism in PC-12 cells. After 24 h exposure to DEPs of 200 nm or smaller, cell viability, ROS and nitric oxide (NO(2)) generation, and levels of dopamine (DA) and its metabolites, (dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA)), were evaluated. Results indicated cell viability was not significantly changed by DEP exposure. However, ROS showed dramatic dose-dependent changes after DEP exposure (2.4 fold increase compared to control at 200 µg/mL). NO(2) levels were also dose-dependently increased after DEP exposure. Although not in a dose-dependent manner, upon DEP exposure, intracellular DA levels were increased while DOPAC and HVA levels decreased when compared to control. Results suggest that ultrafine DEPs lead to dopamine accumulation in the cytoplasm of PC-12 cells, possibly contributing to ROS formation. Further studies are warranted to elucidate this mechanism.

[Current status of external quality assessment of syphilis test in Korea].

BACKGROUND: Current status of external quality assessment (EQA) of laboratory tests for syphilis in Korea was analyzed to find out the problems that should be improved in the future. METHODS: Based on the data from the external quality assessment program performed twice a year by the Immunoserology Subcommittee of the Korean Association of Quality Assurance for Clinical Laboratory from the year 2004 to 2006, discordance rates were analyzed according to the test method and commercial kit used. RESULTS: Among the laboratories participating in the EQA program for syphilis test, about 90% of them used non-treponemal tests and about 55% treponemal tests. The non-treponemal tests included RPR (rapid plasma reagin) and VDRL tests used in 88% (363/412) and 11% (45/412), respectively, of the laboratories. The discordance rates were 2.2% for RPR test and 3.6% for VDRL. For the treponemal tests, Treponema pallidum hemagglutination assay (TPHA) was used in 60-76% and Immunochromatography assay (ICA) in about 30% of the laboratories in 2006. A high discordance rate of over 10% was reported in both TPHA and in ICA methods, possibly due to a low titer (1:1 in VDRL) of EQA samples in 2005. Analysis of the accumulated data from year 2004 to 2006 showed that the discordance rates of TPHA, ICA, and FTA-ABS were 4.6%, 3.7%, and 2.7%, respectively. CONCLUSIONS: For syphilis tests, RPR test, TPHA, and ICA are mainly used in Korea. A high discordance rate is still reported in TPHA and ICA, especially when testing samples with a low titer. Further analysis of data and education of laboratory personnel are needed for the improvement of the EQA program.

[Evaluation of performance and false positivity of Mediace RPR test that uses a chemistry autoanalyzer].

BACKGROUND: We evaluated the performance and false positive rate of Mediace RPR test (Sekisui, Japan), a newly introduced nontreponemal test using a chemistry autoanalyzer. METHODS: The sensitivity of Mediace RPR test was analyzed using sera from 50 patients with syphilis in different stages (8 primary, 7 secondary, and 35 latent), 14 sera positive with fluorescent treponemal antibody absorption (FTA-ABS) IgM, and 74 sera positive with conventional rapid plasma regain (RPR) card test (Asan, Korea) and also positive with Treponema pallidum hemagglutination (TPHA) test or FTA-ABS IgG test. The specificity was analyzed on 108 healthy blood donors. We also performed RPR card test on 302 sera that had been tested positive with Mediace RPR test and also performed TPHA or FTA-ABS IgG test to analyze the false positive rate of Mediace RPR test. A cutoff value of 0.5 R.U. (RPR unit) was used for Mediace RPR test. RESULTS: Mediace RPR test on syphilitic sera of different stages (primary, secondary, and latent stages) and FTA-ABS IgM positive sera showed a sensitivity of 100%, 100%, 82.9% and 100%, respectively. Among the 74 sera positive with conventional RPR card test and TPHA or FTA-ABS IgG test, 55 were positive with Mediace test. The specificity of Mediace RPR test on blood donors was 97.2%. Among the 302 sera positive with Mediace RPR test, 137 sera (45.4%) were negative by RPR card and TPHA/FTA-ABS IgG tests. CONCLUSIONS: Although the sensitivities of Mediace RPR were good for primary and secondary syphilis, due to its high negative rate of Mediace RPR over the conventional RPR positive samples, further studies are necessary whether it can replace conventional nontreponemal test for screening purpose. Moreover, in view of the high false positive rate, positive results by Mediace RPR test should be confirmed with treponemal tests.

Comparison of VERSANT Hepatitis B virus DNA 3.0 Assay with Digene Hybrid Capture II Hepatitis B virus DNA test in relation to clinical status of Hepatitis B virus.

BACKGROUND: Some differences exist among various Hepatitis B virus (HBV) DNA quantification assays due to lack of standardization and besides clinical usefulness has not been firmly elucidated in Korean HBV patients. METHODS: We compared Bayer VERSANT HBV DNA 3.0 Assay (VERSANT 3.0) with Digene Hybrid Capture II HBV DNA Test (HC-II) according to HBeAg status and ALT levels in 232 HBV-infected Korean patients. One hundred and seventeen sera with undetectable DNA levels by HC-II were further analyzed by Real-Q HBV quantification assay (BioSewoom). RESULTS: Although VERSANT 3.0 and HC-II showed an excellent correlation (r=0.9739), the results (copies/mL) by VERSANT 3.0 were 0.45 log(10) higher than those by HC-II. HBV DNA levels were higher in HBeAg-positive group than in HBeAg-negative group (P=0.002), and in abnormal ALT group than in normal ALT group (P<0.0001). The detection rate of HBV DNA by VERSANT 3.0 was lower in HBeAg-negative and normal ALT group (n=68) than in HBeAg-positive or abnormal ALT group (n=164) (35.3% vs 89.6%, P<0.0001). Fifty two sera out of 61 sera with undetectable DNA by VERSANT 3.0 were measurable by Real-Q with mean value of 3.26 log(10) copies/mL. CONCLUSIONS: VERSANT 3.0 and HC-II showed an excellent correlation, but a little difference (0.45 log10) existed. VERSANT 3.0 effectively measured clinically relevant HBV DNA levels in most HBV-infected patients in Korea. However, more sensitive assays are needed for patients with negative HBeAg and normal ALT to see the low copies of HBV DNA levels.