192 research outputs found
Inhibition of methane and natural gas hydrate formation by altering the structure of water with amino acids
Natural gas hydrates are solid hydrogen-bonded water crystals containing small molecular gases. The amount of natural gas stored as hydrates in permafrost and ocean sediments is twice that of all other fossil fuels combined. However, hydrate blockages also hinder oil/gas pipeline transportation, and, despite their huge potential as energy sources, our insufficient understanding of hydrates has limited their extraction. Here, we report how the presence of amino acids in water induces changes in its structure and thus interrupts the formation of methane and natural gas hydrates. The perturbation of the structure of water by amino acids and the resulting selective inhibition of hydrate cage formation were observed directly. A strong correlation was found between the inhibition efficiencies of amino acids and their physicochemical properties, which demonstrates the importance of their direct interactions with water and the resulting dissolution environment. The inhibition of methane and natural gas hydrate formation by amino acids has the potential to be highly beneficial in practical applications such as hydrate exploitation, oil/gas transportation, and flow assurance. Further, the interactions between amino acids and water are essential to the equilibria and dynamics of many physical, chemical, biological, and environmental processes.11Ysciescopu
Novel next generation sequencing panel method for the multiple detection and identification of foodborne pathogens in agricultural wastewater
Detecting and identifying the origins of foodborne pathogen outbreaks is a challenging. The Next-Generation Sequencing (NGS) panel method offers a potential solution by enabling efficient screening and identification of various bacteria in one reaction. In this study, new NGS panel primer sets that target 18 specific virulence factor genes from six target pathogens (Bacillus cereus, Yersinia enterocolitica, Staphylococcus aureus, Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus) were developed and optimized. The primer sets were validated for specificity and selectivity through singleplex PCR, confirming the expected amplicon size. Crosscheck and multiplex PCR showed no interference in the primer set or pathogenic DNA mixture. The NGS panel analysis of spiked water samples detected all 18 target genes in a single reaction, with pathogen concentrations ranging from 108 to 105 colony-forming units (CFUs) per target pathogen. Notably, the total sequence read counts from the virulence factor genes showed a positive association with the CFUs per target pathogen. However, the method exhibited relatively low sensitivity and occasional false positive results at low pathogen concentrations of 105 CFUs. To validate the detection and identification results, two sets of quantitative real-time PCR (qPCR) analyses were independently performed on the same spiked water samples, yielding almost the same efficiency and specificity compared to the NGS panel analysis. Comparative statistical analysis and Spearman correlation analysis further supported the similarity of the results by showing a negative association between the NGS panel sequence read counts and qPCR cycle threshold (Ct) values. To enhance NGS panel analysis for better detection, optimization of primer sets and real-time NGS sequencing technology are essential. Nonetheless, this study provides valuable insights into applying NGS panel analysis for multiple foodborne pathogen detection, emphasizing its potential in ensuring food safety
Inhibitory Effects of Hwangryunhaedok-Tang in 3T3-L1 Adipogenesis by Regulation of Raf/MEK1/ERK1/2 Pathway and PDK1/Akt Phosphorylation
Hwangryunhaedok-tang (HRT) has been long used as traditional medicine in Asia. However, inhibitory role of HRT is unclear in early stage of 3T3-L1 adipocyte differentiation related to signaling. In the present study, we investigated the inhibitory effects of HRT on upstream signaling of peroxisome proliferation-activity receptor-γ (PPAR-γ) and CCAAT/enhancer binding protein-β (C/EBP-β) expression in differentiation of 3T3-L1 preadipocytes. We found that HRT significantly inhibited the adipocyte differentiation by downregulating several adipocyte-specific transcription factors including PPAR-γ, C/EBP-α, and C/EBP-β in 3T3-L1 preadipocytes. Furthermore, we observed that HRT markedly inhibited the differentiation media-mediated phosphorylation of Raf/extracellular mitogen-activated protein kinase 1 (MEK1)/signal-regulated protein kinase 1/2 (ERK1/2) and phosphorylation of phosphoinositide-dependent kinase 1 (PDK1)/Akt. These results indicate that anti-adipogenesis mechanism involves the downregulation of the major transcription factors of adipogenesis including PPAR-γ and C/EBP-α through inhibition of Raf/MEK1/ERK1/2 phosphorylation and PDK1/Akt phosphorylation by HRT. Furthermore, high performance liquid chromatography (HPLC) analysis showed HRT contains active antiobesity constituents such as palmatine, berberine, geniposide, baicalin, baicalein, and wogonin. Taken together, this study suggested that anti-adipogenesis effects of HRT were accounted by downregulation of Raf/MEK1/ERK1/2 pathway and PDK1/Akt pathway during 3T3-L1 adipocyte differentiation
Genetic variants of interferon lambda-related genes and chronic kidney disease susceptibility in the Korean population
Background Chronic kidney disease (CKD) is a common condition leading to renal dysfunction and is closely related to increased cardiovascular and mortality risk. CKD is an important public health issue, and recent genetic studies have verified common CKD susceptibility variants. This research examines the interrelationship between candidate genes polymorphisms of interferon lambda (IFNL) induction, its signaling pathway, and CKD. Methods Seventy-five patients with advanced CKD and 312 healthy subjects (as controls) participated in this research. A replication set composed of 172 patients with advanced CKD and 365 controls was used for additional analysis. The genotype of single nucleotide polymorphisms (SNPs) was determined by the Axiom Genome-Wide Human Assay and SNaPshot assay. Results The SNP of IFNL3 was significantly associated with CKD in the codominant (p = 0.02) and dominant models (p = 0.02). In addition, the SNPs of IFNL2 were significantly associated with CKD in the dominant model (p = 0.03), and the SNP of interferon alpha receptor 2 (IFNAR2) was significantly associated with CKD in the log-additive model (p = 0.03). Concerning rs148543092, in the IFNL3 gene, a significant association was observed after pooling the original and replication sets. Conclusion These results indicate that SNPs in the IFNL induction and signal pathway may be associated with CKD risk in the Korean population. Finally, our results also show that the IFNL3 gene variant may be associated with CKD risk
Induced neural stem cells from distinct genetic backgrounds exhibit different reprogramming status
Somatic cells could be directly converted into induced neural stem cells (iNSCs) by ectopic expression of defined transcription factors. However, the underlying mechanism of direct lineage transition into iNSCs is largely unknown. In this study, we examined the effect of genetic background on the direct conversion process into an iNSC state. The iNSCs from two different mouse strains exhibited the distinct efficiency of lineage conversion as well as clonal expansion. Furthermore, the expression levels of endogenous NSC markers, silencing of transgenes, and in vitro differentiation potential were also different between iNSC lines from different strains. Therefore, our data suggest that the genetic background of starting cells influences the conversion efficiency as well as reprogramming status of directly converted iNSCs.ope
Effects of remote ischemic postconditioning on hepatic injury in lipopolysaccharide-induced endotoxemic rats
Background Remote ischemic postconditioning (RIPoC) is induced by several cycles of brief, reversible, mechanical blood flow occlusion, and reperfusion of the distal organs thereby protecting target organs. We investigated if RIPoC ameliorated liver injury in a lipopolysaccharide (LPS)-induced endotoxemic rats. Methods Protocol 1) Rats were administered LPS and samples collected at 0, 2, 6, 12, and 18 h. 2) After RIPoC at 2, 6, and 12 h (L+2R+18H, L+6R+18H, and L+12R+18H), samples were analyzed at 18 h. 3) RIPoC was performed at 2 h, analysis samples at 6, 12, 18 h (L+2R+6H, L+2R+12H, L+2R+18H), and RIPoC at 6 h, analysis at 12 h (L+6R+12H). 4) Rats were assigned to a control group while in the RIPoC group, RIPoC was performed at 2, 6, 10, and 14 h, with samples analyzed at 18 h. Results Protocol 1) Liver enzyme, malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), and nuclear factor-κB (NF-κB) levels increased while superoxide dismutase (SOD) levels decreased over time. 2) Liver enzyme and MDA levels were lower while SOD levels were higher in L+12R+18H and L+6R+18H groups when compared with L+2R+18H group. 3) Liver enzyme and MDA levels were lower while SOD levels were higher in L+2R+6H and L+6R+12H groups when compared with L+2R+12H and L+2R+18H groups. 4) Liver enzyme, MDA, TNF-α, and NF-κB levels were lower while SOD levels were higher in RIPoC group when compared with control group. Conclusions RIPoC attenuated liver injury in the LPS-induced sepsis model by modifying inflammatory and oxidative stress response for a limited period
In vivo bioluminescence imaging for leptomeningeal dissemination of medulloblastoma in mouse models
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the Creative Commons license, and indicate if changes were made.Abstract
Background
The primary cause of treatment failure in medulloblastomas (MB) is the development of leptomeningeal dissemination (seeding). For translational research on MB seeding, one of the major challenges is the development of reliable experimental models that simulate the seeding and growth characteristics of MBs. To overcome this obstacle, we improved an experimental mouse model by intracisternal inoculation of human MB cells and monitoring with in vivo live images.
Methods
Human MB cells (UW426, D283 and MED8A) were transfected with a firefly luciferase gene and a Thy1.1 (CD90.1) marker linked with IRES under the control of the CMV promoter in a retroviral DNA backbone (effLuc). The MB-effLuc cells were injected into the cisterna magna using an intrathecal catheter, and bioluminescence images were captured. We performed histopathological analysis to confirm the extent of tumor seeding.
Results
The luciferase activity of MB-effLuc cells displayed a gradually increasing pattern, which correlated with a quantitative luminometric assay. Live imaging showed that the MB-effLuc cells were diffusely distributed in the cervical spinal cord and the lumbosacral area. All mice injected with UW426-effLuc, D283-effLuc and MED8A-effLuc died within 51 days. The median survival was 22, 41 and 12 days after injection of 1.2 × 106 UW426-effLuc, D283-effLuc and MED8A-effLuc cells, respectively. The histopathological studies revealed that the MB-effLuc cells spread extensively and diffusely along the leptomeninges of the brain and spinal cord, forming tumor cell-coated layers. The tumor cells in the subarachnoid space expressed a human nuclei marker and Ki-67. Compared with the intracerebellar injection method in which the subfrontal area and distal spinal cord were spared by tumor cell seeding in some mice, the intracisternal injection model more closely resembled the widespread leptomeningeal seeding observed in MB patients.
Conclusion
The results and described method are valuable resources for further translational research to overcome MB seeding
Comparison of Concomitant Mesalamine and Immunomodulator Therapy and Immunomodulator Monotherapy for Crohn’s Disease
Failure to demonstrate Borna disease virus genome in peripheral blood mononuclear cells from psychiatric patients in Korea
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