17 research outputs found

    Molecular Probes to Evaluate the Synthesis and Production Potential of an Odorous Compound (2-methylisoborneol) in Cyanobacteria

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    The volatile metabolite, 2-Methylisoborneol (2-MIB) produced by cyanobacterial species, causes odor and taste problems in freshwater systems. However, simple identification of cyanobacteria that produce such off-flavors may be insufficient to establish the causal agent of off-flavor-related problems as the production-related genes are often strain-specific. Here, we designed a set of primers for detecting and quantifying 2-MIB-synthesizing cyanobacteria based on mibC gene sequences (encoding 2-MIB synthesis-catalyzing monoterpene cyclase) from various Oscillatoriales and Synechococcales cyanobacterial strains deposited in GenBank. Cyanobacterial cells and environmental DNA and RNA were collected from both the water column and sediment of a eutrophic stream (the Gong-ji Stream, Chuncheon, South Korea), which has a high 2-MIB concentration. Primer sets mibC196 and mibC300 showed universality to mibC in the Synechococcales and Oscillatoriales strains; the mibC132 primer showed high specificity for Pseudanabaena and Planktothricoides mibC. Our mibC primers showed excellent amplification efficiency (100–102%) and high correlation among related variables (2-MIB concentration with water RNA r = 689, p < 0.01; sediment DNA r = 0.794, p < 0.01; and water DNA r = 0.644, p < 0.05; cyanobacteria cell density with water RNA and DNA r = 0.995, p < 0.01). These primers offer an efficient tool for identifying cyanobacterial strains possessing mibC genes (and thus 2-MIB-producing potential) and for evaluating mibC gene expression as an early warning of massive cyanobacterial occurrence

    Complete atrioventricular block as an initial manifestation of recurred oral cavity cancer: a case report

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    Abstract Background Intracardiac invasion of head and neck cancer is extremely rare. Here, we report a case of recurred oral cavity cancer presenting with complete atrioventricular (AV) block caused by cardiac metastasis. Case presentation A 70-year-old male presented with dizziness for 2 days. He had a history of oral cavity cancer a year ago, and the tumor was treated by surgical excision after induction chemotherapy and concurrent chemoradiation therapy. Electrocardiography showed complete AV block with ventricular escape rate of 43 beats per minute. Cardiac imaging revealed about 4.0 × 2.0 cm-sized mass invading interventricular septum and AV nodes and protruding into the right ventricle. Magenetic resonance imaging of head and neck demonstrated recurred mass in oral cavity and maxillary sinus. Fluorodeoxyglucose-positron emission tomography showed hypermetabolic lesion in both oral cavity and the heart around interventricular septum and atrioventricular node indicating recurred oral cavity cancer with cardiac metastasis. Permament pacemaker of DDD type was implanted for the symptomatic complete AV block, and palliative chemotherapy was initiated. Conclusion The present case demonstrated that oral cavity cancer can metastasize to the heart, and complete AV block may be an initial manifestation of the recurrence of extracardiac cancer with intracardiac invasion

    Discovery of GSK3β Inhibitors through In Silico Prediction-and-Experiment Cycling Strategy, and Biological Evaluation

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    Direct inhibitors of glycogen synthase kinase 3β (GSK3β) have been investigated and reported for the past 20 years. In the search for novel scaffold inhibitors, 3000 compounds were selected through structure-based virtual screening (SBVS), and then high-throughput enzyme screening was performed. Among the active hit compounds, pyrazolo [1,5-a]pyrimidin-7-amine derivatives showed strong inhibitory potencies on the GSK3β enzyme and markedly activated Wnt signaling. The result of the molecular dynamics (MD) simulation, enhanced by the upper-wall restraint, was used as an advanced structural query for the SBVS. In this study, strong inhibitors designed to inhibit the GSK3β enzyme were discovered through SBVS. Our study provides structural insights into the binding mode of the inhibitors for further lead optimization

    Serum CYFRA 21.1 Level Predicts Disease Course in Thyroid Cancer with Distant Metastasis

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    Background: Serum Cyfra 21.1, the soluble fragment of CK19, has been used as a prognostic tumor marker in various cancers, indicating poor tumor differentiation and increased metastasis. Methods: We analyzed the serum Cyfra 21.1 level in 51 consecutive patients with thyroid cancer manifesting distant metastasis treated with prior total thyroidectomy. Serum Cyfra 21.1 levels of 26 thyroid cancer patients without metastasis and 50 healthy individuals were used for comparison. Results: Higher serum Cyfra 21.1 levels were detected in thyroid cancer patients with distant metastasis compared with healthy subjects and thyroid cancer patients without metastasis (p = 0.012). Serum Cyfra 21.1 levels were significantly increased in patients with positive BRAF V600E mutation (p = 0.019), undergoing Tyrosine Kinase Inhibitor (TKI) therapy (p = 0.008), with radioiodine-refractory status (p = 0.047), and in disease progression compared with those manifesting stable disease (p = 0.007). In progressive disease with undetectable or unmonitored thyroglobulin because of thyroglobulin antibody, serum Cyfra 21.1 was useful as a biomarker for follow-up of disease course. Conclusion: Serum Cyfra 21.1 in thyroid cancer patients might represent an alternative biomarker predicting tumor progression, especially in cases not associated with serum Tg levels

    Enhanced chemical reactivity of graphene by fermi level modulation

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    Among various approaches to modify the electronic and chemical properties of graphene, functionalization is one of the most facile ways to tailor these properties. The rearranged structure with covalently bonded diazonium molecules exhibits distinct semiconducting property, and the attached diazonium enables subsequent chemical reactions. Notably, the rate of diazonium functionalization depends on the substrate and the presence of strain. Meanwhile, according to the Gerischer-Marcus theory, this reactivity can be further tuned by adjusting the Fermi level. Here, we precisely controlled the Fermi level of graphene by introducing the self-assembled monolayer (SAM) and investigated the degree of chemical reactivity of graphene with respect to the doping types. The n-doped graphene exhibited the highest reactivity not only for diazonium molecules but also for metal ions. The increased reactivity is originated from a remarkable electron donor effect over the entire area. In addition, the n-doped graphene enabled spatially patterned functionalization of diazonium molecules, which was further utilized as a growth template for gold particles that would be advantageous for enhanced electrochemical reactivity

    Carotid plaque rather than intima-media thickness as a predictor of recurrent vascular events in patients with acute ischemic stroke

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    Abstract Background To investigate the impacts of carotid plaque and intima-media thickness (IMT) on future vascular events (VEs) in the patients with acute ischemic stroke. Methods A total of 479 consecutive Korean patients with acute ischemic stroke were divided into 2 groups according to development of VEs; VE group (65.4 ± 10.9 years) vs no VE group (62.8 ± 13.2 years). VEs were defined as the development of recurrent stroke, coronary events, peripheral arterial disease, and death. Clinical, laboratory, and imaging findings were compared between the groups. Results During 105.5 ± 29.0 months of follow up, VEs were developed in 142 patients (29.6%). In univariate analysis, VEs were significantly associated with age, gender, diabetes, renal function, lipid levels, left ventricular function, carotid plaque or IMT. In multivariate analysis, the presence of carotid plaque, diabetes, renal function and male gender were independent predictors of future VEs in the patients with ischemic stroke, but carotid IMT was not a predictor of future VEs. Event free survival was significantly lower in patients with carotid plaque than without carotid plaque on Kaplan-Meier analysis (log rank p < 0.001). Conclusion The present study demonstrated that diabetes, impaired renal function, male gender, and the presence of carotid plaque rather than IMT were independent predictors of future VEs in Korean patients with acute ischemic stroke. Active medical management and careful monitoring for the development of recurrent VEs are strongly recommended in patients with acute ischemic stroke and carotid plaque

    Comparison of FDG PET/CT and Bone Marrow Biopsy Results in Patients with Diffuse Large B Cell Lymphoma with Subgroup Analysis of PET Radiomics

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    Whether FDG PET/CT can replace bone marrow biopsy (BMBx) is undecided in patients with diffuse large B cell lymphoma (DLBCL). We compared the visual PET findings and PET radiomic features, with BMBx results. A total of 328 patients were included; 269 (82%) were PET-negative and 59 (18%) were PET-positive for bone lesions on visual assessment. A fair degree of agreement was present between PET and BMBx findings (ĸ = 0.362, p p = 0.037 for high grey-level zone emphasis; mean 308.8 ± 394.4 versus 135.7 ± 97.2, unadjusted p = 0.048 for short-zone high grey-level emphasis), but statistical significance was not found after multiple comparison correction. Visual FDG PET/CT assessment and BMBx results were discordant in 17% of patients with newly diagnosed DLBCL, and the two tests are complementary in the evaluation of bone involvement

    Bioorthogonal Copper Free Click Chemistry for Labeling and Tracking of Chondrocytes <i>In Vivo</i>

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    Establishment of an appropriate cell labeling and tracking method is essential for the development of cell-based therapeutic strategies. Here, we are introducing a new method for cell labeling and tracking by combining metabolic gylcoengineering and bioorthogonal copper-free Click chemistry. First, chondrocytes were treated with tetraacetylated N-azidoacetyl-d-mannosamine (Ac<sub>4</sub>ManNAz) to generate unnatural azide groups (-N<sub>3</sub>) on the surface of the cells. Subsequently, the unnatural azide groups on the cell surface were specifically conjugated with near-infrared fluorescent (NIRF) dye-tagged dibenzyl cyclooctyne (DBCO-650) through bioorthogonal copper-free Click chemistry. Importantly, DBCO-650-labeled chondrocytes presented strong NIRF signals with relatively low cytotoxicity and the amounts of azide groups and DBCO-650 could be easily controlled by feeding different amounts of Ac<sub>4</sub>ManNAz and DBCO-650 to the cell culture system. For the <i>in vivo</i> cell tracking, DBCO-650-labeled chondrocytes (1 × 10<sup>6</sup> cells) seeded on the 3D scaffold were subcutaneously implanted into mice and the transplanted DBCO-650-labeled chondrocytes could be effectively tracked in the prolonged time period of 4 weeks using NIRF imaging technology. Furthermore, this new cell labeling and tracking technology had minimal effect on cartilage formation <i>in vivo</i>
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