Health risk assessment and source apportionment of PM2.5-bound toxic elements in the industrial city of Siheung, Korea.

The emission sources and their health risks of fine particulate matter (PM2.5) in Siheung, Republic of Korea, were investigated as a middle-sized industrial city. To identify the PM2.5 sources with error estimation, a positive matrix factorization model was conducted using daily mean speciated data from November 16, 2019, to October 2, 2020 (95 samples, 22 chemical species). As a result, 10 sources were identified: secondary nitrate (24.3%), secondary sulfate (18.8%), traffic (18.8%), combustion for heating (12.6%), biomass burning (11.8%), coal combustion (3.6%), heavy oil industry (1.8%), smelting industry (4.0%), sea salts (2.7%), and soil (1.7%). Based on the source apportionment results, health risks by inhalation of PM2.5 were assessed for each source using the concentration of toxic elements portioned. The estimated cumulative carcinogenic health risks from the coal combustion, heavy oil industry, and traffic sources exceeded the benchmark, 1E-06. Similarly, carcinogenic health risks from exposure to As and Cr exceeded 1E-05 and 1E-06, respectively, needing a risk reduction plan. The non-carcinogenic risk was smaller than the hazard index of one, implying low potential for adverse health effects. The probable locations of sources with relatively higher carcinogenic risks were tracked. In this study, health risk assessment was performed on the elements for which mass concentration and toxicity information were available; however, future research needs to reflect the toxicity of organic compounds, elemental carbon, and PM2.5 itself.

Association of Tandem Repeat Number Variabilities in Subunit S of the Type I Restriction-Modification System with Macrolide Resistance in Mycoplasma pneumoniae.

Mycoplasma pneumoniae is one of the major pathogens responsible for pneumonia in children. Modern molecular genetics has advanced both the management and the epidemiologic study of this disease. Despite these advancements, macrolide resistance remains a global threat in the management of M. pneumoniae infection, for which the genetic background remains unrevealed. In this study, the result of whole genome analysis of 20 sequence type 3 (ST3) M. pneumoniae strains were examined to investigate the gene(s) associated with macrolide resistance. Overall, genetic similarities within M. pneumoniae, and especially ST3, were very high (over 99.99 %). Macrolide resistant ST3 strains shared 20 single nucleotide polymorphisms, of which one gene (mpn085) was found to be associated with resistance. BLAST comparison of M. pneumoniae revealed regular tandem repeat number variabilities between macrolide-susceptible and resistant strains for genes coding the Type I restriction-modification (R-M) system of subunit S (HsdS). Of the ten known HsdS genes, macrolide resistance was determined by the unique tandem repeat of mpn085 and mpn285. In conclusion, the use of whole genome sequencing (WGS) to target macrolide resistance in M. pneumoniae indicates that the determinant of macrolide resistance is variabilities in the tandem repeat numbers of the type I R-M system in subunit S.

Sources of airborne particulate matter-bound metals and spatial-seasonal variability of health risk potentials in four large cities, South Korea.

Fifteen airborne particulate matter-bound metals were analyzed at 14 sites in four large cities (Seoul, Incheon, Busan, Daegu) in South Korea, between August 2013 and June 2017. Among the seven sources resolved by positive matrix factorization, soil dust and marine aerosol accounted for the largest and second largest portions in the three cities; however, in Seoul, soil dust and traffic occupied the largest and the second largest, respectively. Non-carcinogenic risk assessed by inhalation of eight metals (Cd, Co, Ni, Pb, As, Al, Mn, and V) was greater than the hazard index (HI) of 1 at four sites located at or near the industrial complexes. Cumulative incremental lifetime cancer risk (ILCR) due to exposure to five metals (Cd, Co, Ni, Pb, and As) exceeded the 10-6 cancer benchmark at 14 sites and 10-5 at six sites, which includes four sites with HI greater than 1. The largest contributor to ILCR was coal combustion in Seoul, Incheon, and Daegu, and industry sources in Busan. Moreover, industry sources were the largest contributors to non-carcinogenic risk in Seoul, Busan, and Daegu, and soil dust was in Incheon. Incheon had the highest HI in spring because of the higher contribution of soil dust sources than in other seasons. The higher ILCR in Incheon in spring and winter and higher ILCR and HI in Daegu in autumn were mainly due to the influence of industry or coal combustion sources. Statistically significant differences in the ILCR and HI values among the sampling sites in Busan and Daegu resulted from the higher contribution of industry sources at a certain site in the respective city.

Social inequality, noise pollution, and quality of life of slum dwellers in Pokhara, Nepal.

This work is a cross-sectional comparative study conducted on 528 residents in the slum and non-slum areas of Pokhara, Nepal. Of the total number of respondents, 90.2% in the slums and 63.3% in the non-slums indicated the existence of a main source of noise, and 80.7% in the slums and 66.0% in the non-slums replied that they had been highly annoyed by noise. The indoor noise levels measured for 24 h were higher in slums than in non-slums, ranging from 59 to 78 dBA and from 51 to 69 dBA, respectively. The Mann-Whitney U test showed a significantly poorer status of slum dwellers in four health domains. Logistic regression analysis identified that living in a slum was a significant predictor (OR, 2.35; 95% CI, 1.35-4.09) of a low level of health. Meanwhile, a high level of noise annoyance was a good determinant (OR, 6.71; 95% CI, 3.13-14.36) of low quality of life among slum dwellers revealing a distinguishing negative effect of the high level of noise annoyance in the slum areas.

Open waste burning contrary to other air pollution-related perceptions and practices in Pokhara, Nepal.

A cross-sectional survey was conducted in Pokhara, Nepal between February 3 and 12, 2018 to determine whether air pollution-related perceptions led to a reduction in open burning of waste. Of the 394 people interviewed, 58.3% expressed their concerns about health risks due to air quality. Multiple logistic regression identified that perceived health risk (AOR, 5.70; 95% CI, 3.44-9.45) was a significant predictor of refraining from actions that increase air pollution. While 90.6% of people used trash lorry to dispose domestic waste, 40.6% treated domestic waste by open burning. Unexpectedly, a high level of perceived health risks (AOR 1.72; 95% CI, 1.02-2.91), a high rated contribution of open waste burning to air pollution (AOR, 1.71; 95% CI, 1.06-2.78), and frequent refraining from actions that increase air pollution (AOR, 1.78; 95% CI, 1.08-2.94) were significant predictors of frequent open waste burning. The results implied urgent need for improvement in waste collection efficiency and raising awareness of health risks of open waste burning.

Inhibitory effect of Cudratricusxanthone A on osteoclast differentiation and function.

BACKGROUND: Cudratricusxanthone A (CTXA) was isolated from Cudrania tricuspidata and its anti-inflammatory, hepatoprotective, and anti-proliferative activities have previously been studied in vitro. However, effects of CTXA on osteoclast differentiation have not been investigated. PURPOSE: In this study, the effect of CTXA from C. tricuspidata on in vitro osteoclastogenesis was studied. DESIGN/METHODS: CTXA was isolated from the roots of C. tricuspidata. The effects of CTXA on the RANKL-induced osteoclastogenesis, actin ring formation, and bone resorption were tested by using the RAW 264.7 cells and mouse bone marrow monocytes (BMMs). RESULTS: The structure of CTXA was identified by comparison with spectral data in the literature. We also checked the effect of CTXA on in vitro osteoclastogenesis. CTXA significantly inhibited the JNK/MAPK signaling pathway without affecting ERK and p38 signaling in RANKL-stimulated RAW 264.7 cells and BMMs. Moreover, it inhibited RANKL-induced expression of c-Fos and NFATc1. CONCLUSION: In conclusion, CTXA suppresses osteoclast differentiation by inhibiting RANKL-induced MAPK signaling and attenuates bone resorption by disrupting actin ring formation in mature osteoclasts. These results suggest that CTXA inhibits bone resorption through an inhibitory effect on osteoclast formation and function.

Estimation of CO2 emissions from waste incinerators: Comparison of three methods.

Climate-relevant CO2 emissions from waste incineration were compared using three methods: making use of CO2 concentration data, converting O2 concentration and waste characteristic data, and using a mass balance method following Intergovernmental Panel on Climate Change (IPCC) guidelines. For the first two methods, CO2 and O2 concentrations were measured continuously from 24 to 86 days. The O2 conversion method in comparison to the direct CO2 measurement method had a 4.8% mean difference in daily CO2 emissions for four incinerators where analyzed waste composition data were available. However, the IPCC method had a higher difference of 13% relative to the direct CO2 measurement method. For three incinerators using designed values for waste composition, the O2 conversion and IPCC methods in comparison to the direct CO2 measurement method had mean differences of 7.5% and 89%, respectively. Therefore, the use of O2 concentration data measured for monitoring air pollutant emissions is an effective method for estimating CO2 emissions resulting from waste incineration.

In vitro inhibition of human cytochrome P450 by cudratricusxanthone A.

Cudratricusxanthone A (CTXA) isolated from the roots of Cudrania tricuspidata Bureau (Moraceae) has several biological activities, including hepatoprotective, neuroprotective, anti-inflammatory, monoamine oxidase inhibitory, and antithrombotic activities. In this study, we investigated the potential herb-drug interaction of CTXA and nine cytochrome P450 (CYP) isoforms in pooled human liver microsomes (HLMs) using a cocktail probe assay. CTXA reversibly inhibited the CYP1A2-catalyzed phenacetin O-deethylation, CYP2C8-catalyzed paclitaxel 6-hydroxylation, and CYP2C9-catalyzed diclofenac 4'-hydroxylation with half-maximal inhibitory concentration (IC50) values of 3.9, 4.7, and 2.9 µM, respectively. The IC50 values did not change under different preincubation conditions. CTXA showed marked dose-dependent, but not time-dependent, inhibition of CYP1A2 and 2C9 activities in HLMs. Dixon plots showed typical competitive inhibition of CYP1A2 and CYP2C9 with Ki values of 1.3 and 1.5 µM, respectively. Further, CTXA inhibited CYP2C8 in a non-competitive manner with a Ki value of 2.2 µM. Our results showed that CTXA reversibly inhibits CYP1A2, 2C8, and 2C9.

Characterization of in vitro metabolites of cudratricusxanthone A in human liver microsomes.

Cudratricusxanthone A (CTXA), isolated from the roots of Cudrania tricuspidata, exhibits several biological activities; however, metabolic biotransformation was not investigated. Therefore, metabolites of CTXA were investigated and the major metabolic enzymes engaged in human liver microsomes (HLMs) were characterized using liquid chromatography-tandem mass spectrometry (LC-MS/MS). CTXA was incubated with HLMs or human recombinant CYPs and UGTs, and analysed by an LC-MS/MS equipped electrospray ionization (ESI) to qualify and quantify its metabolites. In total, eight metabolites were identified: M1-M4 were identified as mono-hydroxylated metabolites during Phase I, and M5-M8 were identified as O-glucuronidated metabolites during Phase II in HLMs. Moreover, these metabolite structures and a metabolic pathway were identified by elucidation of MS(n) fragments and formation by human recombinant enzymes. M1 was formed by CYP2D6, and M2-M4 were generated by CYP1A2 and CYP3A4. M5-M8 were mainly formed by UGT1A1, respectively. While investigating the biotransformation of CTXA, eight metabolites of CTXA were identified by CYPs and UGTs; these data will be valuable for understanding the in vivo metabolism of CTXA.

Primary epiphyseal osteomyelitis caused by mycobacterium species in otherwise healthy toddlers.

BACKGROUND: Mycobacterial osteomyelitis involving only the epiphysis of a long bone is extremely rare, and its clinical and radiographic features remain unclear. The purpose of this study was to characterize mycobacterial epiphyseal osteomyelitis and to identify differences between its features and those reported for epiphyseal osteomyelitis caused by bacteria or unidentified pathogens. METHODS: We retrospectively reviewed the cases of eight children (five males and three females) who presented at a median age of nineteen months (range, twelve to twenty-five months). Clinical findings were compiled. Radiographs and magnetic resonance imaging (MRI) were used to determine local spread of the abscess outside the epiphysis during the disease course. At the time of the latest follow-up evaluation, the presence of limited joint mobility or growth disturbance was determined. Physeal damage was evaluated with use of MRI. RESULTS: Pathogens were identified through multiplex polymerase chain reaction. Mycobacterium bovis bacille Calmette-Guérin (BCG, Tokyo-172 strain) was identified in four patients; Mycobacterium tuberculosis, in three patients; and nontuberculous mycobacterium, in one patient. The lesion was located at the distal femoral epiphysis in six patients, at the proximal tibial epiphysis in one patient, and at the proximal humeral epiphysis in one patient. The abscess was confined to the epiphysis at the time of initial presentation but, over time, extended outside the epiphysis in seven cases. The lesion was initially located in the cartilaginous epiphysis in two patients, which could be diagnosed only on MRI. Seven patients worsened despite surgical drainage and medication, and five required additional surgery. At follow-up at a mean of 4.1 years (range, 1.3 to 7.8 years), focal physeal damage was evident in five patients, and clinical growth disturbance was evident in one patient. CONCLUSIONS: In contrast to the reported benign features of epiphyseal osteomyelitis caused by bacteria or unidentified pathogens, mycobacterial epiphyseal osteomyelitis seems to have an unfavorable clinical course that tends to lead to physeal damage. MRI is useful for early diagnosis of a cartilaginous lesion and evaluation of abscess spread and physeal damage. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Prevertebral vascular and esophageal consideration during percutaneous cervical disc procedures.

STUDY DESIGN: A retrospective review series. OBJECTIVE: To identify vascular anatomy and esophageal deviations that may interfere with a percutaneous anterior approach in cervical spine surgery. SUMMARY OF BACKGROUND DATA: The percutaneous anterior approach has been used for minimally invasive interventions of cervical disc diseases. Although the percutaneous anterior approach is frequently performed, reports of obstructing anatomical structures and procedural risks are limited. METHODS: Cervical magnetic resonance images obtained from December 2012 to April 2013 from a total of 511 patients at Guro Teun Teun Hospital were evaluated in this study. Each axial T2-weighted MR image from the disc levels of C3-C4 to C6-C7 (total, 3066 images) was reviewed to check for the presence of small vessels along the trajectories of percutaneous cervical procedures on the left and right sides. Esophageal deviation was also measured at level C6-C7. RESULTS: Small vessels in the anterior neck were present, respectively, in 50.5% (trajectory on the left side) and in 49.1% (trajectory on the right side) at disc level C3-C4, in 30.3% and 28.8% at C4-C5, in 24.1% and 7.6% at C5-C6, and in 55.2% and 43.1% at C6-C7. There were no differences in the number of small vessels between the left and right sides at the upper cervical level (C3-C4-C5), but small vessels were less frequently observed on the right side at lower cervical levels (C5-C6-C7). Differences in esophageal deviation were also observed, with less deviation to the right side (0.63 ± 0.35 cm) than the left (1.18 ± 0.52 cm). As well, an esophageal diverticulum was observed in 1 case on the left side. CONCLUSION: Although surgical approaches are mostly concerned with the location of pathology to be removed, a right-sided percutaneous approach seems preferable because poses less of a risk of encountering small vessels and causing esophageal injury. LEVEL OF EVIDENCE: 4.

Radiological anatomical consideration of conjoined nerve root with a case review.

Nerve root anomalies are frequently underrecognized regardless of the advances in imaging studies; they are also underappreciated and underreported when encountered surgically. The classification of conjoined nerve roots is based on whether the nerve root emerges at an abnormal level or from an anastomotic branch. In the present report, we describe case with a conjoined nerve root that emerged at a more caudal level than that normally observed that was an undiagnosed on preoperative imaging studies. We also discuss the atypical imaging features obtained through preoperative imaging studies. As observed in the present case, preoperative recognition and diagnosis of such anomalies offer the best opportunity of performing a successful procedure and preventing inadvertent damage to nerve roots intraoperatively.

Apportioning and locating nonmethane hydrocarbon sources to a background site in Korea.

Nonmethane hydrocarbons (NMHCs) measured between April 2004 and March 2005 at a background monitoring site on Sukmo Island, Korea were analyzed to identify and apportion NMHC sources. A total of 7694 samples and 35 NMHC species were analyzed. Positive matrix factorization (PMF), applied to identify and apportion the sources of NMHCs, resolved six sources: two fuel evaporative sources (36.3%), solvent sources (25.4%), mixed sources of vehicle exhaust and combustion (22.8%), petrochemical sources (9.6%), and biogenic sources (5.4%). During the summer, the largest contributors to ozone formation were biogenic sources (48.9% and 79.7% by maximum incremental reactivity and propene-equivalent concentration, respectively), which were situated locally, and secondary sources included solvent sources (22.2% and 7.4%) and fuel evaporative sources (15.6% and 8.2%). For evaporative-1 sources composed of long-lived alkanes, the potential source contribution function (PSCF) technique using 48 h back trajectories revealed oil and gas fields in China as potential source areas of fresh "regional" air masses. In addition, the PSCF results for evaporative-2 sources and a long-lived marker species of vehicle exhaust/combustion sources showed that the NMHC mixing ratio in Sukmo, South Korea was enhanced by long-range transport from the Shandong area in China.

Synthesis and nuclear factor-kappaB inhibitory activities of 6- or 7-methylchroman-2-carboxylic acid N-(substituted) phenylamides.

A series of 6- or 7-methylchroman-2-carboxylic acid N-(substituted) phenylamides (2a-s, 3a-s) were synthesized. Their abilities to inhibit nuclear factor-kappaB (NF-kappaB) activity were evaluated in lipopolysaccharide (LPS)-stimulated macrophage RAW 264.7 cells. Compounds with substituents such as -H, -CH(3), and -CF(3) on the phenyl ring were poor inhibitors of NF-kappaB. The most active NF-kappaB inhibitors contained 4-Cl (3s) and 4-OMe (3g) in the 7-methylchroman-2-carboxamide derivatives and 2-OH (2b) and 4-Cl (2s) in the 6-methylchroman-2-carboxamide derivatives (IC(50): 20.2-24.0 microM). These were slightly more potent than a reference compound, KL-1156 (1) (IC(50): 43.9 microM).

Concise synthesis of Obovatol: Chemoselective ortho-bromination of phenol and survey of Cu-catalyzed diaryl ether couplings.

Concise total synthesis of obovatol (1) was achieved from the commercially available eugenol (5) via linear 4 steps in 40% overall yield. The key features of the synthesis involve the chemoselective orthobromination of phenol in the presence of isolated double bond and the efficient Cu-catalyzed Ullmann coupling of two aromatic moieties for the diaryl ether skeleton.

Adenoviral pneumonia during etanercept treatment in a patient with rheumatoid arthritis.

Inhibitors of tumor necrosis factor-alpha (TNF-alpha) have been approved for treating rheumatoid arthritis. As one of the biological response modifiers, etanercept has also been used in the treatment of psoriatic arthritis and inflammatory bowel disease. While etanercept is effective, certain infectious complications, such as tuberculosis, fungus, and cytomegalovirus, have been reported. We report the first Korean case of adenoviral pneumonia in a 55-year-old female who developed disseminated adenoviral infection following etanercept treatment, which resolved after anti-TNF-alpha discontinuation.

Genetic variability of the fusion protein and circulation patterns of genotypes of the respiratory syncytial virus.

Although antigenic and genetic variations were shown to occur both in the G and F protein of respiratory syncytial virus (RSV), few studies looked at the variation of F gene. The F genotypes were determined by the evaluation of clustering patterns, via the phylogenetic analysis of the nucleotide sequences of a variable region in the F gene. One hundred seventy-nine strains obtained from a children's hospital in Korea over nine consecutive epidemics were included. The relationship between the F and G genotypes was analyzed with the G genotypes previously published by the authors. The phylogenetic analysis of the variable region from the F gene revealed 9 genotypes among 129 group A RSVs and 4 genotypes among 50 group B RSVs. In each of the epidemics, the dominant genotypes were replaced with new genotypes in consecutive epidemics. In each of the epidemics of group B RSVs, the predominant genotype alternated between genotypes. Most of the strains which clustered to a particular F genotype were assigned to particular G genotype(s). By determining the nearly entire sequences of the F genes, we revealed the percentage of the nucleotide differences which resulted in amino acid coding changes was determined to be much great in two distinct variable regions of the F gene. Our results indicated that the F gene of the RSVs may be continuously evolving under selective pressure in a distinct pattern, and that the genetic variability of the F protein is associated with that of the G protein.

Complete mitochondrial genome of a troglobite millipede Antrokoreana gracilipes (Diplopoda, Juliformia, Julida), and juliformian phylogeny.

The complete mitochondrial genome of a troglobite millipede Antrokoreana gracilipes (Verhoeff, 1938) (Dipolopoda, Juliformia, Julida) was sequenced and characterized. The genome (14,747 bp) contains 37 genes (2 ribosomal RNA genes, 22 transfer RNA genes and 13 protein-encoding genes) and two large non-coding regions (225 bp and 31 bp), as previously reported for two diplopods, Narceus annularus (order Spirobolida) and Thyropygus sp. (order Spirostreptida). The A + T content of the genome is 62.1% and four tRNAs (tRNA(Ser(AGN)), tRNA(Cys), tRNA(Ile) and tRNA(Met)) have unusual and unstable secondary structures. Whereas Narceus and Thyropygus have identical gene arrangements, the tRNA(Thr) and tRNA(Trp) of Antrokoreana differ from them in their orientations and/or positions. This suggests that the Spirobolida and Spirostreptida are more closely related to each other than to the Dipolopoda. Three scenarios are proposed to account for the unique gene arrangement of Antrokoreana. The data also imply that the Duplication and Nonrandom Loss (DNL) model is applicable to the order Julida. Bayesian inference (BI) and maximum likelihood (ML) analyses using amino acid sequences deduced from the 12 mitochondrial protein-encoding genes (excluding ATP8) support the view that the three juliformian members are monophyletic (BI 100%; ML 100%), that Thyropygus (Spirostreptida) and Narceus (Spirobolida) are clustered together (BI 100%; ML 83%), and that Antrokoreana (Julida) is a sister of the two. However, due to conflict with previous reports using cladistic approaches based on morphological characteristics, further studies are needed to confirm the close relationship between Spirostreptida and Spirobolida.

Epitheliotropic cutaneous lymphoma (mycosis fungoides) in a dog.

A seven-year-old castrated male Yorkshire terrier dog was presented for a recurrent skin disease. Erythematous skin during the first visit progressed from multiple plaques to patch lesions and exudative erosion in the oral mucosa membrane. Biopsy samples were taken from erythematous skin and were diagnosed with epitheliotropic T cell cutaneous lymphoma by histopathology and immunochemical stain. In serum chemistry, the dog had a hypercalcemia (15.7 mg/dl) and mild increased alkaline phosphatase (417 U/l). Immunohistochemistry was performed to detect parathyroid hormone-related peptide (PTH-rP) in epitheliotropic cutaneous lymphoma tissues but the neoplastic cells were not labeled with anti-PTH-rP antibodies. The patient was treated with prednisolone and isotretinoin. However, the dog died unexpectedly.

Genetic polymorphisms of eosinophil-derived neurotoxin and eosinophil cationic protein in tropical pulmonary eosinophilia.

Because eosinophil-derived neurotoxin (EDN) and eosinophil cationic protein (ECP) are critical in the pathogenesis of tropical pulmonary eosinophilia (TPE), we analyzed genetic polymorphisms of both in 181 individuals from southern India with varying clinical manifestations of Wuchereria bancrofti infection (including 26 with TPE). Using haplotype frequency analysis, we identified four known (of nine) and two novel haplotypes for EDN (1, 2, 7, 8, 10, and 11). For ECP, five (of seven known) haplotypes (1-5) were identified. Although we found no significant association between frequencies of EDN and ECP polymorphisms and TPE development, we observed a unique pattern of EDN and ECP polymorphism distribution among this population. Genotype TT at locus 1088 of ECP in one TPE patient was not observed in any other clinical group. Although the EDN and ECP polymorphisms appear unlikely to be associated with the development of TPE, further analyses will be more definitive.