Molecular Prevalence of Blastocystis sp. from Patients with Diarrhea in the Republic of Korea.

Blastocystis sp. is the most common intestinal protozoan affecting human health worldwide. Several studies have reported the prevalence of Blastocystis sp. in various regions of the Republic of Korea. However, limited data are available on the prevalence and subtype (ST) distribution of this parasite among regions. Therefore, we investigated the prevalence and ST distributions of this parasite in the Republic of Korea. For this purpose, 894 stool specimens were collected from patients with diarrhea and tested for the presence of Blastocystis sp. using PCR analysis. The isolates were subsequently subtyped. The overall prevalence was 11.6%. Of the 104 isolates, ST3 was the most prevalent, followed by ST1. Additionally, a single case of the rare subtype ST8 was identified, representing the first reported case in the Republic of Korea. The results suggested that the predominance of ST3 observed in this study reflects human-to-human transmission with low genetic diversity within the ST, while ST1 transmission is likely correlated with animals. In the future, to better understand Blastocystis sp. transmission dynamics, human, animal, and environmental factors should be studied from a "One Health" perspective.

Spectrally Stable Deep-Blue Light-Emitting Diodes Based on Layer-Transferred Single-Crystalline Ruddlesden-Popper Halide Perovskites.

A novel approach to producing high-color-purity blue-light-emitting diodes based on single-crystalline Ruddlesden-Popper perovskites (RPPs) is reported. The utilization of a pure bromide composition eliminates any possibility of halide segregation, which can otherwise lead to undesired shifts in the emission wavelength or irreversible degradation of the spectral line width. Phase-pure PEA2MAPb2Br7 single crystals with a lateral size exceeding 1 cm2 can be synthesized using the inverse temperature crystallization method. To prepare RPP layers with a thickness of less than 50 nm, we employ a thinning process of the initially thick bulk crystals, followed by a dry-transfer process to place them onto a hole transport layer and an indium-tin-oxide-coated glass substrate. By utilizing polydimethylsiloxane as a handling layer, deformations of the bulk RPP crystal and exfoliated RPP layer, as well as the formation of defects such as pinholes, can be effectively suppressed. Subsequent depositions of an electron transport layer and a metal contact complete the fabrication of electroluminescence (EL) devices. The EL devices utilizing the single-crystalline RPP demonstrate excellent spectral stability across a broad range of the applied bias voltage spanning from 4.5 to 10 V, exhibiting a significantly narrow line width of 14 nm at an emission wavelength of 440 nm that can potentially cover 99.3% of the Rec. 2020 color gamut. The sharp EL emission spectrum can be effectively preserved, avoiding any broadening of the line width, by suppressing Joule heating throughout the device operation, in addition to the intrinsic stability of single-crystalline RPPs.

Kudoa septempunctata Spores Cause Acute Gastroenteric Symptoms in Mouse and Musk Shrew Models as Evidenced In Vitro in Human Colon Cells.

Kudoa septempunctata is a myxosporean parasite that infects the trunk muscles of olive flounder (Paralichthys olivaceus) and has been reported to cause foodborne illnesses in humans. However, the molecular mechanisms underlying K. septempunctata spore toxicity remain largely unknown. In this study, the gastroenteropathy of K. septempunctata was examined in human colon adenocarcinoma cells as well as experimental mice inoculated with spores. We found that K. septempunctata decreased transepithelial resistance and disrupted epithelial tight junctions by deleting ZO-1 in Caco-2 monolayers. Additionally, serotonin (5-HT), an emetic neurotransmitter, was increased in K. septempunctata-inoculated cells. In vivo, K. septempunctata spores induced diarrhea in suckling mice (80% in ddY and 70% in ICR mice), with a minimum provocative dose of 2 × 105 K. septempunctata spores. In house musk shrews, K. septempunctata induced emesis within 1 h and induced serotonin secretion in the intestinal epithelium. In conclusion, K. septempunctata may induce diarrhea and emesis by increasing intestinal permeability and serotonin secretion.

Changes in Vitamin D Status in Korean Adults during the COVID-19 Pandemic.

The aim of this study was to investigate changes in 25(OH)D (25-hydroxyvitamin D) levels and in the vitamin D status of Korean adults before and during the coronavirus disease (COVID-19) pandemic. This study compared serum 25(OH)D levels before and after the pandemic in 1483 adults aged 19 years and older who were screened at a university hospital. Subjects were selected only from participants tested in the same season before and after the pandemic. The pre-COVID-19 testing period was from 1 March 2018 to 31 November 2019; the testing period in the COVID-19 era was from 1 June 2020 to 31 November 2021. The mean 25(OH)D level for all participants was 21.4 ± 10.2 ng/mL prior to the outbreak of COVID-19, which increased to 23.6 ± 11.8 ng/mL during the COVID-19 lockdown period (p < 0.001). The increase was particularly dramatic in elderly females (28.8 ± 12.3 ng/mL to 37.7 ± 18.6 ng/mL, p = 0.008). The prevalence of vitamin D deficiency decreased in both males (48.4% to 44.5%, p = 0.005) and females (57.0% to 46.0%, p < 0.001). In conclusion, 25(OH)D levels in Korean adults increased during the COVID-19 era, and the prevalence of vitamin D deficiency decreased accordingly.

Changes in the prevalence of metabolic syndrome in Korean adults after the COVID-19 outbreak.

OBJECTIVES: This study sought to reveal changes in the prevalence of metabolic syndrome (MetS) after the start of the coronavirus disease 2019 (COVID-19) pandemic and to identify the groups showing the greatest changes. METHODS: We compared the prevalence of MetS between 2017-2019 (i.e., the 3-year period before the COVID-19 pandemic) and soon after the initial outbreak of COVID-19 in 2020 among 24,564 adults ≥ 19 years of age using data from the Korea National Health and Nutrition Examination Survey. RESULTS: The prevalence of MetS increased steadily between 2017 and 2020 (29.4 to 35.3%, p for trend < 0.001), with annual percent changes of 2.0%p, 2.2%p, and 1.7%p, respectively. Compared to 3 years before the COVID-19 pandemic, the prevalence of MetS significantly increased during the COVID-19 pandemic in males (6.2%p; 95% confidence interval [CI], 3.5 to 8.9) compared to females (1.5%p; 95% CI, -1.2 to 4.1). The age groups with the greatest increases in MetS prevalence after the COVID-19 pandemic were those in their 40s (4.6%p; 95% CI, 0.9 to 8.4) and 50s (5.8%p; 95% CI, 2.2 to 9.4). By educational background, the increase in MetS prevalence was greatest among those with a college degree or higher (5.1%p). The prevalence of MetS in high-income (5.3%p) and low-income (4.6%p) groups significantly increased. CONCLUSIONS: The increasing trend in the overall prevalence of MetS continued during the COVID-19 pandemic. In particular, the prevalence of MetS among adult males in their 40s and 50s increased significantly after the COVID-19 outbreak in Korea.

Prenatally Ruptured Patent Urachus: A Case Report and Review of Literature.

Patent urachus is a type of urachal anomaly in which the urachus does not tail off but remains connected to the bladder in the umbilicus. The prevalence of patent urachus is very low. Herein, we report a case of patent urachus ruptured and exposed to amniotic fluid in utero. In this case, the size decreased after the second trimester, which was thought to be due to rupture in utero. After delivery, patent urachus was confirmed by inserting a foley catheter, which runs through a ruptured cyst on umbilical cord insertion. The day after delivery, the neonate underwent surgical excision of the urachal cyst and closing umbilicus. The mechanism of patent urachus rupture is unknown. As the fetus matures, it is thought that the higher intravesical pressure may affect the rupture of the cyst. Patent urachus could be ruptured in the uterus spontaneously, and surgical correction is needed. Therefore, prenatal differential diagnosis is important.

First Identification and Genotyping of Enterocytozoon bieneusi and Prevalence of Encephalitozoon intestinalis in Patients with Acute Diarrhea in the Republic of Korea.

Encephalitozoon intestinalis and Enterocytozoon bieneusi can cause diarrhea in humans, especially severe diarrhea in immunocompromised patients. However, there have been few studies on Enc. intestinalis and Ent. bieneusi in patients with acute diarrhea in the Republic of Korea (ROK). In this study, fecal samples were collected from 1241 patients with acute diarrhea in 2020. Among these, 24 cases of Enc. intestinalis and one case of Ent. bieneusi were detected via PCR amplification of small subunit ribosomal RNA. Genotyping of the internal transcribed spacer region sequence revealed that the detected Ent. bieneusi genotype was in Group 1. This study provides the first evidence that Ent. bieneusi exists in humans in addition to animals in the ROK. To identify the causative agent, continuous monitoring of Enc. intestinalis and Ent. bieneusi is necessary for patients with acute diarrhea in the ROK.

Effects of bioactive glass incorporation into glass ionomer cement on demineralized dentin.

The effects of the incorporation of sodium-free bioactive glass into glass ionomer cement (GIC) on the demineralized dentin are studied. Four experimental groups with various amounts of BAG in GIC were considered: BG0 group: 0 wt% (control); BG5 group: 5 wt%; BG10 group: 10 wt%; BG20 group: 20 wt%. The GIC surface and GIC-approximated demineralized dentin surfaces were evaluated using field emission scanning electron microscopy (FE-SEM). X-ray diffraction (XRD) analysis was performed to evaluate the chemical changes in the GIC-approximated dentin surface. In addition, a shear bond strength test was performed to evaluate the effects of BAG incorporation on the bond strength of GIC. FE-SEM analysis indicated that BAG-incorporated GICs formed distinct precipitates on their surface. Precipitates were also formed on the GIC-approximated demineralized dentin surface. It was more obvious when the amount of BAG increased. In the XRD analysis, fluorapatitie (FAP) peaks were detected in the BG5, BG10, and BG20 groups. There was no significant difference in the shear bond strength among all experimental groups. BAG-incorporated GIC precipitated FAP crystals underlying demineralized dentin surface without affecting bond strength. This study suggests the possibility of BAG as a beneficial additive in GIC.

Diquafosol promotes corneal epithelial healing via intracellular calcium-mediated ERK activation.

Diquafosol is known as a purinergic P2Y2 receptor (P2Y2R) agonist that stimulates water and mucin secretion from conjunctival epithelial cells and goblet cells, leading to tear film stability in dry eye. However, its effect on corneal epithelial healing has not yet been elucidated. The aim of the present study was to evaluate the effect of diquafosol on corneal epithelial healing in vivo and on P2Y2R-related downstream signaling pathways in vitro. We administered 3% diquafosol ophthalmic solution on 3 mm-diameter epithelial defects made in rat corneas and assessed the wound closure over time. Corneal epithelial healing was significantly accelerated in diquafosol-treated eyes compared to control eyes at 12 and 24 h. During wound healing, P2Y2R staining appeared stronger in the re-epithelized margin near the wound defect. To evaluate whether diquafosol stimulates epidermal growth factor receptor/extracellular-signal-regulated kinase (EGFR/ERK)-related cell proliferation and migration, simian virus 40-transfected human corneal epithelial (THCE) cells were used for in vitro experiments. Cell proliferation was accelerated by diquafosol at concentrations from 20 to 200 µM during 48 h, but inhibited at concentrations over 2000 µM. The intracellular calcium ([Ca(2+)]i) elevation was measured in diquafosol (100 µM)-stimulated cells using Fluo-4/AM ([Ca(2+)]i indicator). [Ca(2+)]i elevation was observed in diquafosol-stimulated cells regardless of the presence of calcium in media, and suramin pretreatment inhibited the calcium response. The effect of diquafosol on phosphorylation of EGFR, ERK and Akt, and cell migration was determined by western blotting and in vitro cell migration assay. Diquafosol induced phosphorylation of EGFR at 2 min post-stimulation, and phosphorylation of ERK at 5 min post-stimulation. Phosphorylation of ERK was attenuated in cells pretreated with suramin or BAPTA/AM ([Ca(2+)]i chelator), and partially with AG1478 (EGFR inhibitor). Likewise, diquafosol-treated cells showed acceleration of gap closure in cell migration assay, which was inhibited by suramin, BAPTA/AM, AG1478, and U0126 (MEK inhibitor). These studies demonstrate that diquafosol is effective in promoting corneal epithelial wound healing and that this effect may result from ERK-stimulated cell proliferation and migration via P2Y2R-mediated [Ca(2+)]i elevation.

Pure red phosphorescent organic light-emitting diodes made of iridium(III) complex with thiophene-quinoline ligand.

A cyclometalated iridium(II) complex, bis(2-thiophen-2-yl-quinolinato)(acetoacetonate)iridium(II) [(tq)2Ir(III)(acac)] was synthesized for use in phosphorescent organic light-emitting diodes. The photophysical and electrochemical properties of the iridium(Ill) complex were characterized by UV-visible absorption, photoluminescence, and cyclic voltammetry. The maximum UV-visible absorption of (tq)2Ir(acac) was observed at 289 nm. (Tq)2Ir(acac) in dichloromethane showed its maximum photoluminescence (PL) emission at 629 nm. The optical band gap energy of (tq)2Ir(III)(acac) was measured to be 2.11 eV, and the HOMO energy level of (tq)2Ir(Ill)(acac) was calculated to be -5.08 eV. The T1 state of (tq)2Ir(lll)(acac), calculated from the PL emission maximum (2.01 eV), was well matched with the T1 level of CBP (2.6 eV). The phosphorescent organic light-emitting diode with a configuration of ITO/PEDOT:PSS/alpha-NPD/TCTA/CBP:(tq)2Ir(II)(acac)(8 wt%)/BCP/Alq3/LiF/Al was fabricated and characterized. Light emission from the device was observed at a low turn-on voltage of 4.3 V. The device showed a maximum brightness of 24,000 cd/m2 at 16.3 V and an external quantum efficiency of 11.1% with a Commission Internationale de l'Eclairage (CIE) coordinate of (0.690, 0.310).

Exfoliation of non-oxidized graphene flakes for scalable conductive film.

The increasing demand for graphene has required a new route for its mass production without causing extreme damages. Here we demonstrate a simple and cost-effective intercalation based exfoliation method for preparing high quality graphene flakes, which form a stable dispersion in organic solvents without any functionalization and surfactant. Successful intercalation of alkali metal between graphite interlayers through liquid-state diffusion from ternary KCl-NaCl-ZnCl(2) eutectic system is confirmed by X-ray diffraction and X-ray photoelectric spectroscopy. Chemical composition and morphology analyses prove that the graphene flakes preserve their intrinsic properties without any degradation. The graphene flakes remain dispersed in a mixture of pyridine and salts for more than 6 months. We apply these results to produce transparent conducting (∼930 Ω/□ at ∼75% transmission) graphene films using the modified Langmuir-Blodgett method. The overall results suggest that our method can be a scalable (>1 g/batch) and economical route for the synthesis of nonoxidized graphene flakes.

Outcomes and prognostic factors of cervical cancer after concurrent chemoradiation.

AIM: Concurrent chemoradiation (CCRT) is the standard treatment for locally advanced cervical cancer. This study was undertaken to evaluate the outcomes and the prognostic factors for cervical cancer after CCRT. MATERIAL AND METHODS: The medical records of 174 patients with International Federation of Gynecology and Obstetrics stage IB1-IVA who were treated at three affiliated hospitals of the Catholic University of Korea between January 1999 and December 2008 were reviewed and analyzed. Patients received pelvic radiotherapy with one of three regimens of cisplatin-based chemotherapy concurrently and high-dose rate brachytherapy. The radiation field was extended to include para-aortic lymph nodes, if necessary. RESULTS: The median follow-up period was 29.5 months (range, 5-96 months). Using multivariate analysis, stage (P = 0.014), tumor size (P = 0.043), and clinical response (P = 0.001) had a significant effect on overall survival. Similarly, progression-free survival (PFS) was influenced by stage (P = 0.004), tumor size (P = 0.02), clinical response (P = 0.011), and normalized squamous cell carcinoma antigen level after CCRT (P = 0.007). The 5-year survival rates were 91.7% (standard error, 5.8%) for stages IB1-IIA, 71.5% (standard error, 7.8%) for stage IIB, 44.9% (standard error, 7.8%) for stage III, and 20.9% (standard error, 12.0%) for stage IVA. A total of 151 out of 174 patients (86.8%) completed the planned treatment. Toxicities were manageable with supportive therapy. CONCLUSIONS: Cisplatin-based CCRT is well-tolerated. Good clinical response revealed a favorable correlation to survival. A maximal effort to achieve this goal might prolong survival in patients with cervical cancer.

Antimicrobial resistance of Vibrio parahaemolyticus and Vibrio alginolyticus strains isolated from farmed fish in Korea from 2005 through 2007.

The antimicrobial resistance patterns to 15 antimicrobial agents of Vibrio parahaemolyticus and Vibrio alginolyticus isolated from farmed fishes, including olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), red sea bream (Pagrus major), and sea bass (Lateolabrax japonicus), were investigated from 2005 through 2007. A total of 218 V. parahaemolyticus isolates and 153 V. alginolyticus isolates were obtained from the 180 fish samples collected from fish farms located along the southern coast of Korea. We found that 65.1% of V. parahaemolyticus and 85.6% of V. alginolyticus isolates showed antimicrobial resistance against more than one antimicrobial agent. The prevalence of resistance in V. parahaemolyticus isolates to ampicillin was highest (57.8%), followed by resistance to rifampin (11.9%), streptomycin (8.7%), and trimethoprim (6.4%). V. alginolyticus isolates were also most resistant to ampicillin (75.2%), followed by tetracycline (15.0%), trimethoprim (12.4%), and rifampin (9.8%). The prevalence of multiresistance to four or more antimicrobials was higher in V. alginolyticus (11.1%) than in V. parahaemolyticus (5%). Antimicrobial resistance rates per isolate of V. parahaemolyticus and V. alginolyticus possessing virulence genes were not different from those of the rest of the isolates.

Oncostatin M as a target biological molecule of preeclampsia.

AIM: Given the presence of the cytokinetic effects of Oncostatin M (OSM), we hypothesized that placental expression of OSM and serum OSM levels are elevated in preeclampsia. To verify this hypothesis, we determined the expression of OSM in placenta and levels of OSM in plasma form women with preeclampsia and normal pregnant women. METHODS: Sixteen women with severe preeclampsia and 16 normal pregnancy women were studied. Placental tissues were immediately frozen and stored at -80 degrees C until extraction of total RNA. Total RNA was extracted and real-time quantitative PCR was carried out. Placental tissues fixed in 4% paraformaldehyde were reacted with antibodies against OSM. An independent pathologist who was blind to the origins of the samples reviewed these stained slides. The maternal serum and umbilical venous concentration of OSM were determined by commercially available ELISA analysis. RESULTS: The mRNA expression level of OSM in preeclamptic placenta was increased by 3.91 times which was significantly higher than those of the normal group (P = 0.028). OSM immunoreactivity was significantly higher in placentas of patients with preeclampsia than placentas from the normal group. The significantly greater OSM expressions were noted in cytotrophoblasts, syncytotrophoblasts and endothelium of preeclamptic placentas as compared to normal placentas (respectively, P = 0.004, 0.001 and 0.04). OSM concentration of preeclamptic women's serum was significantly higher than that of normal women's plasma (P = 0.016). However, OSM level of umbilical venous serum was not significantly different between two groups (P = 0.243) CONCLUSION: OSM may play a biological marker for severe preeclampsia, and its action may be predominantly on the trophoblasts and endothelium of placenta villi in preeclampsia.

Involvement of ligand occupancy in Insulin-like growth factor-I (IGF-I) induced cell growth in osteoblast like MC3T3-E1 cells.

Growth factors and matrix proteins regulate the proliferation and differentiation of osteoblasts. The insulin-like growth factor (IGF) system comprises IGF-I, IGF-II, and six high-affinity IGF-binding proteins (IGFBPs). IGFs stimulate cell growth in many types of tissue; IGF-binding proteins regulate cellular actions and can affect cell growth. IGF-I is involved in differentiation, proliferation, and matrix formation in osteoblasts; IGFBP-5 is associated with the extracellular matrix (ECM) and can potentiate the actions of IGF-I. We investigated the effect of ECM proteins on the responses of MC3T3-E1 osteoblast cells to IGF-I and IGFBP-5. In addition, because extracellular signal-regulated kinases 1 and 2 (Erk 1/2) affect cell growth, we evaluated the effects of IGFBP-5 on Erk 1/2 phosphorylation in MC3T3-E1 cells. IGF-I caused an increase in IGFBP-5 expression in cultured MC3T3-E1 cells, and IGF-I plus IGFBP-5 significantly increased cell growth. Likewise, the addition of IGF-I and IGFBP-5 to cultured MC3T3-E1 cells increased the synthesis of the ECM proteins osteopontin (OPN) and thrombospondin-1 (TSP-1), which can bind to alphaVbeta3 integrin receptors on the cell surface. By contrast, the addition of an antibody against ECM proteins inhibited the effects of OPN and TSP-1 on IGFBP-5 expression. The stimulatory effect of IGFBP-5 was mediated via Erk 1/2 activation. These data suggest that IGFBP-5 regulates Erk 1/2 phosphorylation in cultured MC3T3-E1 cells via ECM proteins that may ultimately stimulate the growth of osteoblasts. We determined whether occupation of the alphaVbeta3 integrin receptor affects IGF-I receptor (IGF-IR)-mediated signaling and function in MC3T3-E1 osteoblast cells. Occupation of the alphaVbeta3 integrin receptor with ECM proteins induced IGF-I-stimulated IGF-IR phosphorylation. Conversely, in the presence of the alphaVbeta3-specific disintegrin echistatin, IGF-I-stimulated IGF-IR activation was inhibited. IGF-I-stimulated IGF-IR phosphorylation was accompanied by IRS-1 phosphorylation and MAPK activation. However, these effects were attenuated by echistatin. Thus, occupancy of the alphaVbeta3 disintegrin receptor modulates IGF-I-induced IGF-IR activation and IGF-IR-mediated function in MC 3T3-E1 osteoblasts.

Simple but effective way to sense pyrophosphate and inorganic phosphate by fluorescence changes.

A new fluorescent chemosensor based on the acridine-Zn(II) derivative effectively recognizes pyrophosphate and inorganic phosphate at pH 7.4. Acridine derivative 1 displayed a fluorescent quenching effect with pyrophosphate; on the other hand, a large fluorescent enhancement was observed with inorganic phosphate. [structure: see text].

Removal of residual COD in biologically treated paper-mill effluent and degradation of lignin using nonthermal plasma unit.

This manuscript focused on the degradation behavior of lignin and the reduction of residual COD in the biologically treated paper-mill effluent by means of ionized gas from nonthermal plasma unit. The removal efficiencies of COD, lignin, and color after treated with ionized gas were over 95, 93, and 97%, respectively. It has been found that the degradation of aromatic ring has been proved by FTIR, 1H NMR and UV spectra. The degradation of lignin through ionized gas was accompanied with the increase of SO4(2-) and the decrease in pH. The results show that the residual COD in the biologically treated paper-mill effluent contains NBD matter with aromatic ring compounds. Also NBD organic matter such as aromatic ring in effluent treated with ionized gas was degraded. The residual COD declined by 60% at the ionized gas flow rate 5 L/min and HRT 30 min.