1,926 research outputs found
Transformer-Based Multi-Task Learning for Crisis Actionability Extraction
Social media has become a valuable information source for crisis informatics. While various methods were proposed to extract relevant information during a crisis, their adoption by field practitioners remains low. In recent fieldwork, actionable information was identified as the primary information need for crisis responders and a key component in bridging the significant gap in existing crisis management tools. In this paper, we proposed a Crisis Actionability Extraction System for filtering, classification, phrase extraction, severity estimation, localization, and aggregation of actionable information altogether. We examined the effectiveness of transformer-based LSTM-CRF architecture in Twitter-related sequence tagging tasks and simultaneously extracted actionable information such as situational details and crisis impact via Multi-Task Learning. We demonstrated the system’s practical value in a case study of a real-world crisis and showed its effectiveness in aiding crisis responders with making well-informed decisions, mitigating risks, and navigating the complexities of the crisis
Antimicrobial susceptibility patterns among Escherichia coli urinary isolates from community-onset health care-associated urinary tract infection
Urinary tract infection (UTI) is traditionally classified as community-acquired (CA) and hospital-acquired (HA). Community-onset health care-associated (HCA) infection is a new category that has gained increasing attention. The study aimed to compare the disk susceptibility of nonrepetitive Escherichia coli urinary isolates from HCA-UTI (n = 100) with that of E. coli isolates from CA-UTI (n = 85) and HA-UTI (n = 106). We found that the susceptibility pattern of HCA-UTI E. coli isolates was similar to that of HA-UTI E. coli isolates, but significantly different from that of CA-UTI E. coli isolates. In particular, the proportion of extended-spectrum β-lactamase-producing isolates was significantly higher in HCA-UTI than that in CA-UTI (30.0% vs. 3.5%, p < 0.001). We recommend that when treating HCA-UTI, it is necessary to take urine cultures for susceptibility testing to guide definite antibiotic therapy
Optogenetic regulation of site-specific subtelomeric DNA methylation
Telomere length homeostasis, critical for chromosomal integrity and genome stability, is controlled by intricate molecular regulatory machinery that includes epigenetic modifications. Here, we examine site-specific and spatiotemporal alteration of the subtelomeric methylation of CpG islands using optogenetic tools to understand the epigenetic regulatory mechanisms of telomere length maintenance. Human DNA methyltransferase3A (DNMT3A) were assembled selectively at chromosome ends by fusion to cryptochrome 2 protein (CRY2) and its interacting complement, the basic helix loop helix protein-1 (CIB1). CIB1 was fused to the telomere-associated protein telomere repeat binding factor-1 (TRF1), which localized the protein complex DNMT3A-CRY2 at telomeric regions upon excitation by blue-light monitored by single-molecule fluorescence analyses. Increased methylation was achieved selectively at subtelomeric CpG sites on the six examined chromosome ends specifically after blue-light activation, which resulted in progressive increase in telomere length over three generations of HeLa cell replications. The modular design of the fusion constructs presented here allows for the selective substitution of other chromatin modifying enzymes and for loci-specific targeting to regulate the epigenetic pathways at telomeres and other selected genomic regions of interest
Bmi-1 Regulates Snail Expression and Promotes Metastasis Ability in Head and Neck Squamous Cancer-Derived ALDH1 Positive Cells
Recent studies suggest that ALDH1 is a putative marker for HNSCC-derived cancer
stem cells. However, the regulation mechanisms that maintain the stemness and metastatic capability
of HNSCC-ALDH1+ cells remain unclear. Initially, HNSCC-ALDH1+ cells from HNSCC patient showed
cancer stemness properties, and high expression of Bmi1 and Snail. Functionally, tumorigenic properties
of HNSCC-ALDH1+ cells could be downregulated by knockdown of Bmi-1. Overexpression of Bmi-1 altered in
expression property ALDH1− cells to that of ALDH1+ cells. Furthermore, knockdown of Bmi-1 enhanced
the radiosensitivity of radiation-treated HNSCC-ALDH1+ cells. Moreover, overexpression of Bmi-1 in
HNSCC-ALDH1− cells increased tumor volume and number of pulmonary metastatic lesions by xenotransplant
assay. Importantly, knock-down of Bmi1 in HNSCC-ALDH1+ cells significantly decreased distant metastases in
the lungs. Clinically, coexpression of Bmi-1/Snail/ALDH1 predicted the worst prognosis in HNSCC
patients. Collectively, our data suggested that Bmi-1 plays a key role in
regulating Snail expression and cancer stemness properties of HNSCC-ALDH1+ cells
Genetic polymorphisms in glutathione S-transferase (GST) superfamily and risk of arsenic-induced urothelial carcinoma in residents of southwestern Taiwan
<p>Abstract</p> <p>Background</p> <p>Arsenic exposure is an important public health issue worldwide. Dose-response relationship between arsenic exposure and risk of urothelial carcinoma (UC) is consistently observed. Inorganic arsenic is methylated to form the metabolites monomethylarsonic acid and dimethylarsinic acid while ingested. Variations in capacity of xenobiotic detoxification and arsenic methylation might explain individual variation in susceptibility to arsenic-induced cancers.</p> <p>Methods</p> <p>To estimate individual susceptibility to arsenic-induced UC, 764 DNA specimens from our long-term follow-up cohort in Southwestern Taiwan were used and the genetic polymorphisms in GSTM1, GSTT1, GSTP1 and arsenic methylation enzymes including GSTO1 and GSTO2 were genotyped.</p> <p>Results</p> <p>The GSTT1 null was marginally associated with increased urothelial carcinoma (UC) risk (HR, 1.91, 95% CI, 1.00-3.65), while the association was not observed for other GSTs. Among the subjects with cumulative arsenic exposure (CAE) ≥ 20 mg/L*year, the GSTT1 null genotype conferred a significantly increased cancer risk (RR, 3.25, 95% CI, 1.20-8.80). The gene-environment interaction between the GSTT1 and high arsenic exposure with respect to cancer risk was statistically significant (multiplicative model, <it>p </it>= 0.0151) and etiologic fraction was as high as 0.86 (95% CI, 0.51-1.22). The genetic effects of GSTO1/GSTO2 were largely confined to high arsenic level (CAE ≥ 20). Diplotype analysis showed that among subjects exposed to high levels of arsenic, the AGG/AGG variant of GSTO1 Ala140Asp, GSTO2 5'UTR (-183)A/G, and GSTO2 Asn142Asp was associated with an increased cancer risk (HRs, 4.91, 95% CI, 1.02-23.74) when compared to the all-wildtype reference, respectively.</p> <p>Conclusions</p> <p>The GSTs do not play a critical role in arsenic-induced urothelial carcinogenesis. The genetic effects of GSTT1 and GSTO1 on arsenic-induced urothelial carcinogenesis are largely confined to very high exposure level.</p
High-level expression and molecular characterization of a recombinant prolidase from Escherichia coli NovaBlue
Long-term use of organophosphorus (OP) compounds has become an increasing global problem and a major threat to sustainability and human health. Prolidase is a proline-specific metallopeptidase that can offer an efficient option for the degradation of OP compounds. In this study, a full-length gene from Escherichia coli NovaBlue encoding a prolidase (EcPepQ) was amplified and cloned into the commercially-available vector pQE-30 to yield pQE-EcPepQ. The overexpressed enzyme was purified from the cell-free extract of isopropyl thio-β-D-galactoside IPTG-induced E. coli M15 (pQE-EcPepQ) cells by nickel-chelate chromatography. The molecular mass of EcPepQ was determined to be about 57 kDa by 12% sodium dodecyl sulfate–polyacrylamide gel electrophoresis and the result of size-exclusion chromatography demonstrated that the enzyme was mainly present in 25 mM Tris–HCl buffer (pH 8.0) as a dimeric form. The optimal conditions for EcPepQ activity were 60 °C, pH 8.0, and 0.1 mM Mn2+ ion. Kinetic analysis with Ala-Pro as the substrate showed that the Km and kcat values of EcPepQ were 8.8 mM and 926.5 ± 2.0 s−1, respectively. The thermal unfolding of EcPepQ followed a two-state process with one well-defined unfolding transition of 64.2 °C. Analysis of guanidine hydrochloride (GdnHCl)-induced denaturation by tryptophan emission fluorescence spectroscopy revealed that the enzyme had a [GdnHCl]0.5,N-U value of 1.98 M. The purified enzyme also exhibited some degree of tolerance to various water/organic co-solvents. Isopropanol and tetrahydrofuran were very detrimental to the enzymatic activity of EcPepQ; however, other more hydrophilic co-solvents, such as formamide, methanol, and ethylene glycol, were better tolerated. Eventually, the non-negative influence of some co-solvents on both catalytic activity and structural stability of EcPepQ allows to adjust the reaction conditions more suitable for EcPepQ-catalyzed bioprocess
Switch activation of PI-PLC downstream signals in activated macrophages with wortmannin
AbstractPhosphatidylinositol (4,5)-bisphosphate (PtdIns(4,5)P2) has been known to serve as a substrate for phosphatidylinositol 3-kinase (PI3K) and phosphoinositide-specific phospholipase C (PI-PLC), which can produce PtdIns(3,4,5)P3 and inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) and diacylglycerol (DAG), respectively. In this study, we elucidated the role of PI-PLC during the LPS-activated mouse macrophages RAW264.7 treated with PI3K inhibitor wortmannin. First, wortmannin treatment enhanced Ins(1,4,5)P3 production and iNOS expression in LPS-activated macrophages. Inhibition of PI3K by p85 siRNA also showed an enhancement of iNOS expression. On the other hand, overexpression of PI3K by ras-p110 expression plasmid significantly decreased iNOS expression in LPS-activated macrophages. In addition, overexpression of wild-type or dominant-negative Akt expression plasmid did not affect the iNOS expression in LPS-activated macrophages. Second, treatment of PI-PLC inhibitor U73122 reversed the enhancement of iNOS expression, the increase of phosphorylation level of ERK, JNK and p38, and the increase of AP-1-dependent gene expression in wortmannin-treated and LPS-activated macrophages. However, NF-κB activity determined by EMSA assay and reporter plasmid assay did not change during LPS-activated macrophages with or without wortmannin. We propose that the inhibition of PI3K by wortmannin in mouse macrophages enhances the PI-PLC downstream signals, and subsequently increases the LPS induction of iNOS expression independently of Akt pathway
A Combined DNA-Affinic Molecule and N-Mustard Alkylating Agent Has an Anti-Cancer Effect and Induces Autophagy in Oral Cancer Cells
Although surgery or the combination of chemotherapy and radiation are reported to improve the quality of life and reduce symptoms in patients with oral cancer, the prognosis of oral cancer remains generally poor. DNA alkylating agents, such as N-mustard, play an important role in cancer drug development. BO-1051 is a new 9-anilinoacridine N-mustard-derivative anti-cancer drug that can effectively target a variety of cancer cell lines and inhibit tumorigenesis in vivo. However, the underlying mechanism of BO-1051-mediated tumor suppression remains undetermined. In the present study, BO-1051 suppressed cell viability with a low IC50 in oral cancer cells, but not in normal gingival fibroblasts. Cell cycle analysis revealed that the tumor suppression by BO-1051 was accompanied by cell cycle arrest and downregulation of stemness genes. The enhanced conversion of LC3-I to LC3-II and the formation of acidic vesicular organelles indicated that BO-1501 induced autophagy. The expression of checkpoint kinases was upregulated as demonstrated with Western blot analysis, showing that BO-1051 could induce DNA damage and participate in DNA repair mechanisms. Furthermore, BO-1051 treatment alone exhibited a moderate tumor suppressive effect against xenograft tumor growth in immunocompromised mice. Importantly, the combination of BO-1051 and radiation led to a potent inhibition on xenograft tumorigenesis. Collectively, our findings demonstrated that BO-1051 exhibited a cytotoxic effect via cell cycle arrest and the induction of autophagy. Thus, the combination of BO-1051 and radiotherapy may be a feasible therapeutic strategy against oral cancer in the future
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