Synergistic apoptosis by combination of metformin and an O-GlcNAcylation inhibitor in colon cancer cells.

BACKGROUND: Although autophagy is an important mediator of metformin antitumor activity, the role of metformin in the crosstalk between autophagy and apoptosis remains unclear. The aim was to confirm the anticancer effect by inducing apoptosis by co-treatment with metformin and OSMI-1, an inhibitor of O-GlcNAcylation, in colon cancer cells. METHODS: Cell viability was measured by MTT in colon cancer cell lines HCT116 and SW620 cells. Co-treatment with metformin and OSMI-1 induced autophagy and apoptosis, which was analyzed using western blot, reverse transcription-polymerase chain reaction (RT-PCR) analysis, and fluorescence-activated cell sorting (FACS). Combined treatment with metformin and OSMI-1 synergistically inhibit the growth of HCT116 was confirmed by xenograft tumors. RESULTS: We showed that metformin inhibited mammalian target of rapamycin (mTOR) activity by inducing high levels of C/EBP homologous protein (CHOP) expression through endoplasmic reticulum (ER) stress and activating adenosine monophosphate-activated protein kinase (AMPK) to induce autophagy in HCT116 cells. Interestingly, metformin increased O-GlcNAcylation and glutamine:fructose-6-phosphate amidotransferase (GFAT) levels in HCT116 cells. Thus, metformin also blocks autophagy by enhancing O-GlcNAcylation, whereas OSMI-1 increases autophagy via ER stress. In contrast, combined metformin and OSMI-1 treatment resulted in continuous induction of autophagy and disruption of O-GlcNAcylation homeostasis, resulting in excessive autophagic flux, which synergistically induced apoptosis. Downregulation of Bcl2 promoted apoptosis via the activation of c-Jun N-terminal kinase (JNK) and CHOP overexpression, synergistically inducing apoptosis. The activation of IRE1α/JNK signaling by OSMI-1 and PERK/CHOP signaling by metformin combined to inhibit Bcl2 activity, ultimately leading to the upregulation of cytochrome c release and activation of caspase-3. CONCLUSIONS: In conclusion, combinatorial treatment of HCT116 cells with metformin and OSMI-1 resulted in more synergistic apoptosis being induced by enhancement of signal activation through ER stress-induced signaling rather than the cell protective autophagy function. These results in HCT116 cells were also confirmed in xenograft models, suggesting that this combination strategy could be utilized for colon cancer treatment.

First Case of Pseudoclavibacter alba Bacteremia in a Patient with Cholangitis.

BACKGROUND: Pseudoclavibacter alba isolated from human urine in culture collection was introduced as a new species, but since then, no other reports on P. alba isolated from the environment or organisms have been published. We thus present the first case report of P. alba bacteremia. METHODS: An 85-year-old female patient was admitted with intermittent abdominal pain and chills that had persisted for one week. She was diagnosed cholangitis with common bile duct stones. RESULTS: Gram-positive bacteria were detected in her peripheral blood culture and identified Pseudoclavibacter species by matrix-assisted laser desorption-ionization-time of flight mass spectrometry. Pseudoclavibacter alba was identified by performing the 16S ribosomal RNA gene sequence. CONCLUSIONS: This is the first case report of P. alba bacteremia in a patient with cholangitis.

Ambient Stable All Inorganic CsCu2I3 Artificial Synapses for Neurocomputing.

In resistive switching memories or artificial synaptic devices, halide perovskites have attracted attention for their unusual features such as rapid ion migration, adjustable composition, and facile synthesis. Herein, the environmentally friendly and highly air stable CsCu2I3 perovskite films are used as the active layer in the Au/CsCu2I3/ITO/glass artificial synapses. The device shows variable synaptic plasticities such as long-term and short-term synaptic plasticity, paired-pulse facilitation, and spike-timing-dependent plasticity by combining potentiation and depression along the formation of conductive filaments. The performances of the devices are maintained for 160 days under ambient conditions. Additionally, the accuracy evaluation of the CsCu2I3-based artificial synapses performs exceptionally well with the MNIST and Fashion MNIST data sets, demonstrating high learning accuracy in deep neural networks. Using the novel B-site engineered halide perovskite material with extreme air stability, this study paves the way for artificial synaptic devices for next-generation in-memory hardware.

CD74 Promotes a Pro-Inflammatory Tumor Microenvironment by Inducing S100A8 and S100A9 Secretion in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive form of pancreatic cancer with a poor prognosis and low survival rates. The prognostic and predictive biomarkers of PDAC are still largely unknown. The receptor CD74 was recently identified as a regulator of oncogenic properties in various cancers. However, the precise molecular mechanism of CD74 action in PDAC remains little understood. We investigated the role of CD74 by silencing CD74 in the pancreatic cancer cell line Capan-1. CD74 knockdown led to reductions in cell proliferation, migration, and invasion and increased apoptosis. Moreover, silencing CD74 resulted in the decreased expression and secretion of S100A8 and S100A9. An indirect co-culture of fibroblasts and tumor cells revealed that fibroblasts exposed to conditioned media from CD74 knockdown cells exhibited a reduced expression of inflammatory cytokines, suggesting a role of CD74 in influencing cytokine secretion in the tumor microenvironment. Overall, our study provides valuable insights into the critical role of CD74 in regulating the oncogenic properties of pancreatic cancer cells and its influence on the expression and secretion of S100A8 and S100A9. Taken together, these findings indicate CD74 as a potential diagnostic biomarker and therapeutic target for pancreatic cancer.

Anti-Adipogenic Effects of Salicortin from the Twigs of Weeping Willow (Salix pseudolasiogyne) in 3T3-L1 Cells.

Salix pseudolasiogyne (Salicaceae), the "weeping willow," has been used in traditional Korean medicine to treat pain and fever due to its high concentrations of salicylic acid and salicin. The present study investigated bioactive compounds from S. pseudolasiogyne twigs to discover bioactive natural products. Phytochemical investigation of the ethanol (EtOH) extract of S. pseudolasiogyne twigs followed by liquid chromatography-mass spectrometry (LC/MS)-based analysis led to the isolation of two salicin derivatives, salicortinol and salicortin, the structures of which were determined by interpretation of their NMR spectra and data from the LC/MS analysis. To the best of our knowledge, this is the first report of salicortinol isolated from S. pseudolasiogyne. The isolated compounds were evaluated for their anti-adipogenic effects in 3T3-L1 cells. Both salicortinol and salicortin were found to significantly inhibit adipocyte differentiation in 3T3-L1 cells. In particular, salicortin exhibited a strong inhibitory effect on lipid accumulation. Furthermore, salicortin inhibited the expression of lipogenic and adipogenic transcription factors, including FASN, FABP4, C/EBPα, C/EBPß, and PPARγ, without inducing cytotoxicity. These results suggest that salicortin could be a potential therapeutic compound for the prevention or treatment of metabolic disorders such as obesity.

Bakuchiol, main component of root bark of Ulmus davidiana var. japonica, inhibits TGF-ß-induced in vitro EMT and in vivo metastasis.

Cancer is a second leading cause of death worldwide, and metastasis is the major cause of cancer-related mortality. The epithelial-mesenchymal transition (EMT), known as phenotypic change from epithelial cells to mesenchymal cells, is a crucial biological process during development. However, inappropriate activation of EMT contributes to tumor progression and promoting metastasis; therefore, inhibiting EMT is considered a promising strategy for developing drugs that can treat or prevent cancer. In the present study, we investigated the anti-cancer effect of bakuchiol (BC), a main component of Ulmus davidiana var. japonica, in human cancer cells using A549, HT29 and MCF7 cells. In MTT and colony forming assay, BC exerted cytotoxicity activity against cancer cells and inhibited proliferation of these cells. Anti-metastatic effects by BC were further confirmed by observing decreased migration and invasion in TGF-ß-induced cancer cells after BC treatment. Furthermore, BC treatment resulted in increase of E-cadherin expression and decrease of Snail level in Western blotting and immunofluorescence analysis, supporting its anti-metastatic activity. In addition, BC inhibited lung metastasis of tail vein injected human cancer cells in animal model. These findings suggest that BC inhibits migration and invasion of cancers by suppressing EMT and in vivo metastasis, thereby may be a potential therapeutic agent for treating cancers.

Intraoperative radiation therapy induces immune response activity after pancreatic surgery.

BACKGROUND: Pancreatic cancer has highly aggressive features, such as local recurrence that leads to significantly high morbidity and mortality and recurrence after successful tumour resection. Intraoperative radiation therapy (IORT), which delivers targeted radiation to a tumour bed, is known to reduce local recurrence by directly killing tumour cells and modifying the tumour microenvironment. METHODS: Among 30 patients diagnosed with pancreatic cancer, 17 patients received IORT immediately after surgical resection. We investigated changes in the immune response induced by IORT by analysing the peritoneal fluid (PF) and blood of patients with and without IORT treatment after pancreatic cancer surgery. Further, we treated three pancreatic cell lines with PF to observe proliferation and activity changes. RESULTS: Levels of cytokines involved in the PI3K/SMAD pathway were increased in the PF of IORT-treated patients. Moreover, IORT-treated PF inhibited the growth, migration, and invasiveness of pancreatic cancer cells. Changes in lymphocyte populations in the blood of IORT-treated patients indicated an increased immune response. CONCLUSIONS: Based on the characterisation and quantification of immune cells in the blood and cytokine levels in the PF, we conclude that IORT induced an anti-tumour effect by activating the immune response, which may prevent pancreatic cancer recurrence. CLINICAL TRIAL REGISTRATION: NCT03273374 .

OSMI-1 Enhances TRAIL-Induced Apoptosis through ER Stress and NF-κB Signaling in Colon Cancer Cells.

Levels of O-GlcNAc transferase (OGT) and hyper-O-GlcNAcylation expression levels are associated with cancer pathogenesis. This study aimed to find conditions that maximize the therapeutic effect of cancer and minimize tissue damage by combining an OGT inhibitor (OSMI-1) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). We found that OSMI-1 treatment in HCT116 human colon cancer cells has a potent synergistic effect on TRAIL-induced apoptosis signaling. Interestingly, OSMI-1 significantly increased TRAIL-mediated apoptosis by increasing the expression of the cell surface receptor DR5. ROS-induced endoplasmic reticulum (ER) stress by OSMI-1 not only upregulated CHOP-DR5 signaling but also activated Jun-N-terminal kinase (JNK), resulting in a decrease in Bcl2 and the release of cytochrome c from mitochondria. TRAIL induced the activation of NF-κB and played a role in resistance as an antiapoptotic factor. During this process, O-GlcNAcylation of IκB kinase (IKK) and IκBα degradation occurred, followed by translocation of p65 into the nucleus. However, combination treatment with OSMI-1 counteracted the effect of TRAIL-mediated NF-κB signaling, resulting in a more synergistic effect on apoptosis. Therefore, the combined treatment of OSMI-1 and TRAIL synergistically increased TRAIL-induced apoptosis through caspase-8 activation. Conclusively, OSMI-1 potentially sensitizes TRAIL-induced cell death in HCT116 cells through the blockade of NF-κB signaling and activation of apoptosis through ER stress response.

Lead-Free Dual-Phase Halide Perovskites for Preconditioned Conducting-Bridge Memory.

Organometallic and all-inorganic halide perovskites (HPs) have recently emerged as promising candidate materials for resistive switching (RS) nonvolatile memory due to their current-voltage hysteresis caused by fast ion migration. Lead-free and all-inorganic HPs have been researched for non-toxic and environmentally friendly RS memory devices. However, only HP-based devices with electrochemically active top electrode (TE) exhibit ultra-low operating voltages and high on/off ratio RS properties. The active TE easily reacts to halide ions in HP films, and the devices have a low device durability. Herein, RS memory devices based on an air-stable lead-free all-inorganic dual-phase HP (AgBi2 I7 -Cs3 Bi2 I9 ) are successfully fabricated with inert metal electrodes. The devices with Au TE show filamentary RS behavior by conducting-bridge involving Ag cations in HPs with ultra-low operating voltages (<0.15 V), high on/off ratio (>107 ), multilevel data storage, and long retention times (>5 × 104 s). The use of a closed-loop pulse switching method improves reversible RS properties up to 103 cycles with high on/off ratio above 106 . With an extremely small bending radius of 1 mm, the devices are operable with reasonable RS characteristics. This work provides a promising material strategy for lead-free all-inorganic HP-based nonvolatile memory devices for practical applications.

Amentoflavone, active compound of Selaginella tamariscina, inhibits in vitro and in vivo TGF-ß-induced metastasis of human cancer cells.

Epithelial mesenchymal transition (EMT) is a well-known and important step in metastasis and thus can be a key target in cancer treatment. Here, we tested the EMT inhibitory actions of Selaginella tamariscina and its active component, amentoflavone (AF). EMT was examined in vitro using wound-healing and invasion assays and by monitoring changes in the expression of the EMT-related proteins, E-cadherin, Snail, and Twist. Metastasis was examined in vivo using SCID mice injected with luciferase-labeled A549 cells. We confirmed that aqueous extracts of S. tamariscina (STE) and AF inhibited EMT in human cancer cell lines. We found that STE and AF at nontoxic concentrations exerted remarkable inhibitory effects on migration (wound healing assay) and invasion (Transwell assay) in tumor necrosis factor (TGF)-ß-treated cancer cells. Western blotting and immunofluorescence imaging show that AF treatment also restored E-cadherin expression in these cells compared to cells treated with TGF-ß only. Suppression of metastasis by AF was investigated by monitoring migration of tail-vein-injected, circulating A549-luc cells to the lungs in mice. After 3 wk, fewer nodules were observed in mice co-treated with AF compared with those treated with TGF-ß only. Our findings indicate that STE and AF are promising EMT inhibitors and, ultimately, potentially potent antitumor agents.

Clinical Validation of Non-Invasive Prenatal Testing for Fetal Common Aneuploidies in 1,055 Korean Pregnant Women: a Single Center Experience.

BACKGROUND: Non-invasive prenatal testing (NIPT) using cell-free fetal DNA from maternal plasma for fetal aneuploidy identification is expanding worldwide. The objective of this study was to evaluate the clinical utility of NIPT for the detection of trisomies 21, 18, and 13 of high-risk fetus in a large Korean population. METHODS: This study was performed retrospectively, using stored maternal plasma from 1,055 pregnant women with singleton pregnancies who underwent invasive prenatal diagnosis because of a high-risk indication for chromosomal abnormalities. The NIPT results were confirmed by karyotype analysis. RESULTS: Among 1,055 cases, 108 cases of fetal aneuploidy, including trisomy 21 (n = 57), trisomy 18 (n = 42), and trisomy 13 (n = 9), were identified by NIPT. In this study, NIPT showed 100% sensitivity and 99.9% specificity for trisomy 21, and 92.9% sensitivity and 100% specificity for trisomy 18, and 100% sensitivity and 99.9% specificity for trisomy 13. The overall positive predictive value (PPV) was 98.1%. PPVs for trisomies 21, 18, and 13 ranged from 90.0% to 100%. CONCLUSION: This study demonstrates that our NIPT technology is reliable and accurate when applied to maternal DNA samples collected from pregnant women. Further large prospective studies are needed to adequately assess the performance of NIPT.

Silibinin Ameliorates O-GlcNAcylation and Inflammation in a Mouse Model of Nonalcoholic Steatohepatitis.

The mechanisms underlying the progression to non-alcoholic steatohepatitis (NASH) remain to be elucidated. In the present study, we aimed to identify the proteins involved in the pathogenesis of liver tissue inflammation and to investigate the effects of silibinin, a natural polyphenolic flavonoid, on steatohepatitis. We performed comparative proteomic analysis using methionine and choline-deficient (MCD) diet-induced NASH model mice. Eighteen proteins were identified from the two-dimensional proteomic analysis, which are not only differentially expressed, but also significantly improved, by silibinin treatment. Interestingly, seven of these proteins, including keratin cytoskeletal 8 and 18, peroxiredoxin-4, and protein disulfide isomerase, are known to undergo GlcNAcylation modification, most of which are related to structural and stress-related proteins in NASH model animals. Thus, we primarily focused on how the GlcNAc modification of these proteins is involved in the progression to NASH. Remarkably, silibinin treatment alleviates the severity of hepatic inflammation along with O-GlcNAcylation in steatohepatitis. In particular, the reduction of inflammation by silibinin is due to the inhibition of the O-GlcNAcylation-dependent NF-κB-signaling pathway. Therefore, silibinin is a promising therapeutic agent for hyper-O-GlcNAcylation as well as NASH.

New Potential Biomarker Proteins for Alcoholic Liver Disease Identified by a Comparative Proteomics Approach.

Chronic alcohol consumption causes hepatic steatosis, which is characterized by a considerable increase in free fatty acid (FFA) and triglyceride levels. To identify the possible proteins involved in the progression to alcoholic hepatosteatosis, we performed proteomic analysis on livers of mice exposed to alcohol. 2D-based proteomic analysis revealed that EtOH exposure in mice changed the expression of 43 proteins compared with that in mice fed a normal diet (ND). The most notable protein changes were proteins involved in Met metabolism and oxidative stress, most of which were significantly downregulated in alcohol-exposed animals. Although non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) seem to share the same molecular processes, the difference between these conditions is still unclear. To address this question, we explored the features of alcoholic hepatosteatosis that were different compared with those of methionine and choline deficient (MCD) diet-induced mice with nonalcoholic liver damage. Although most of the differentially expressed proteins associated with ALD did not significantly differ from those of NAFLD, nine proteins showed considerably different patterns. Of these, ornithine aminotransferase, vitamin D binding protein, and phosphatidylethanolamine-binding protein were considerably upregulated in ALD mice, compared to that in NAFLD and ND mice. However, other proteins including inorganic pyrophosphatase were differentially regulated in MCD mice; however, they did not differ significantly between the alcoholic model and ND control mice. These results suggested that the identified proteins might be useful candidate markers to differentiate ALD from NAFLD. J. Cell. Biochem. 118: 1189-1200, 2017. © 2016 Wiley Periodicals, Inc.

Mach-Zehnder Interferometer Refractive Index Sensor Based on a Plasmonic Channel Waveguide.

A Mach-Zehnder interferometer based on a plasmonic channel waveguide is proposed for refractive index sensing. The structure, with a small physical footprint of 20 × 120 µm², achieved a high figure of merit of 294. The cut-off frequency behaviour in the plasmonic channel waveguide resulted in a flat dispersion curve, which induces a 1.8 times larger change of the propagation constant for the given refractive index change compared with previously reported results.

The antiwrinkle and antimelanogenic effects of the nonedible part of Sorghum bicolor (L.) Moench and their augmentation by fermentation.

Sorghum [Sorghum bicolor (L.) Moench] is a major cereal crop. Despite the wide cultivation of sorghum, its stalks are used as hay and silage. The plant has numerous bioactive compounds including cosmeceutical ingredients. Thus, we investigated the antimelanogenic and SSE that is prepared from the stalk of Sorghum bicolor L. (SSE) after ethanol (EtOH) extraction. Based on the antioxidant capacity, antityrosinase activity, and suppression of the protein expression levels of matrix metalloproteinase (MMP)-1, -2, and -3 in human neonatal foreskin HDF-N cells, a 50% EtOH extraction of SSEs showed antimelanogenic and antiwrinkle potential. To enrich the cosmeceutical potential of SSE, a fermentation process was applied to SSE with the use of the fungus Aspergillus oryzae NK ( f SSE). On additional fermentation, the cosmeceutical potential of SSE increased with further enhancement of antityrosinase activity and suppression of MMP-1, -2, and -3 protein expression. SSE contains p-coumaric acid, and its level was enriched by the fermentation process. Collectively, SSE and its fermented product can serve as good ingredients in new cosmeceutical compounds.

Metabolomic Profiles of Aspergillus oryzae and Bacillus amyloliquefaciens During Rice Koji Fermentation.

Rice koji, used early in the manufacturing process for many fermented foods, produces diverse metabolites and enzymes during fermentation. Using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS), ultrahigh-performance liquid chromatography linear trap quadrupole ion trap tandem mass spectrometry (UHPLC-LTQ-IT-MS/MS), and multivariate analysis we generated the metabolite profiles of rice koji produced by fermentation with Aspergillus oryzae (RK_AO) or Bacillus amyloliquefaciens (RK_BA) for different durations. Two principal components of the metabolomic data distinguished the rice koji samples according to their fermenter species and fermentation time. Several enzymes secreted by the fermenter species, including α-amylase, protease, and ß-glucosidase, were assayed to identify differences in expression levels. This approach revealed that carbohydrate metabolism, serine-derived amino acids, and fatty acids were associated with rice koji fermentation by A. oryzae, whereas aromatic and branched chain amino acids, flavonoids, and lysophospholipids were more typical in rice koji fermentation by B. amyloliquefaciens. Antioxidant activity was significantly higher for RK_BA than for RK_AO, as were the abundances of flavonoids, including tricin, tricin glycosides, apigenin glycosides, and chrysoeriol glycosides. In summary, we have used MS-based metabolomics and enzyme activity assays to evaluate the effects of using different microbial species and fermentation times on the nutritional profile of rice koji.

Spatial mapping of refractive index based on a plasmonic tapered channel waveguide.

A tapered plasmonic channel waveguide can be used for index sensing by spatial mapping of the scattering field intensity. A numerical simulation shows that this waveguide reflects the plasmonic channel waveguide mode at various points as the refractive index of an analyte changes, and a strong outgoing scattering wave appears at the reflection point. One can measure the index change by detecting variations in the scattering point. In the case of a unit index change, the scattering point moved 2670 nm, which can be observed by an imaging system. Detection limit of the index change is estimated as 0.12. However, the limit can be further reduced by increasing the tapered length or decreasing the tapered angle of the structure.

MicroRNAs as potential biomarkers for noninvasive detection of fetal trisomy 21.

PURPOSE: The objective of this study was to discover a panel of microRNAs (miRNAs) as potential biomarkers for noninvasive prenatal testing (NIPT) of trisomy 21 (T21) and to predict the biological functions of identified biomarkers using bioinformatics tools. METHODS: Using microarray-based genome-wide expression profiling, we compared the expression levels of miRNAs in whole blood samples from non-pregnant women, whole blood samples from pregnant women with euploid or T21 fetuses, and placenta samples from euploid or T21 fetuses. We analyzed the differentially expressed miRNAs according to disease and tissue type (P value <0.05 and two-fold expression change). To predict functions of target genes of miRNAs, the functional annotation tools were used. RESULTS: We identified 299 miRNAs which reasonably separate the whole blood from the placenta. Among the identified miRNAs, 150 miRNAs were up-regulated in the placenta, and 149 miRNAs were down-regulated. Most of the up-regulated miRNAs in the placenta were members of the mir-498, mir-379, and mir-127 clusters. Among the up-regulated miRNAs in the placenta, mir-1973 and mir-3196 were expressed at higher levels in the T21 placenta than in the euploid placenta. The two miRNAs potentially regulate 203 target genes that are involved in development of brain, central nervous system, and nervous system. The genes are significantly associated with T21-related disorder such as congenital abnormalities, mental disorders, and nervous system diseases. CONCLUSIONS: Our study indicates placenta-specific miRNAs that may be potential biomarkers for NIPT of fetal T21 and provides new insights into the molecular mechanisms of T21 via regulation of miRNAs.

Non-invasive detection of fetal trisomy 21 using fetal epigenetic biomarkers with a high CpG density.

BACKGROUND: Non-invasive prenatal test of trisomy 21 (T21) is being researched using fetal specific epigenetic biomarkers present in maternal plasma. We applied a methyl-CpG binding domain-based protein (MBD) method based on epigenetic characteristics of fetal specific-methylated regions with a high CpG density in HLCS on chromosome 21 and RASSF1A on chromosome 3 for the non-invasive detection of fetal T21 and estimated the diagnostic accuracy of the method. METHODS: A nested case-control study was conducted with maternal plasma collected from 50 pregnant women carrying 40 normal and 10 T21 fetuses. A MBD method was used for enrichment of methylated DNA regions in maternal plasma. The levels of methylated HLCS (M-HLCS) and methylated RASSF1A (M-RASSF1A) were simultaneously measured by multiplex qPCR. RESULTS: Levels of M-HLCS and M-RASSF1A were obtained in all cases. Levels were not different according to fetal gender (p>0.05 in both). The level of M-HLCS was significantly increased in women with a T21 fetus compared with controls (p<0.001). The level of M-RASSF1A was not different between two groups (p>0.05). In non-invasive fetal T21 detection, the specificity of M-HLCS level and the epigenetic-epigenetic ratio (EER) using M-HLCS and M-RASSF1A levels were 82.5% and 92.5%, respectively, at 90.0% sensitivity. CONCLUSIONS: Our findings suggest that the EER may be useful as a potential biomarker for the non-invasive detection of fetal T21, regardless of fetal gender. The MBD method can be used as an effective tool in the detection of methylated fetal specific markers with a high CpG density in maternal plasma.

Clonal Distribution and Its Association With the Carbapenem Resistance Mechanisms of Carbapenem-Non-Susceptible Pseudomonas aeruginosa Isolates From Korean Hospitals.

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals. Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC ß-lactamase. Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates. Two high-risk clones, ST235 (N=41) and ST111 (N=20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metallo-ß-lactamase (MBL) genes, blaIMP-6 (N=38), blaVIM-2 (N=3), and blaNDM-1 (N=2), were detected. blaIMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried blaNDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene-negative isolates. Conclusions: Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.