70 research outputs found

    Identification and Characterization of a Dual-Acting Antinematodal Agent against the Pinewood Nematode, Bursaphelenchus xylophilus

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    The pinewood nematode (PWN), Bursaphelenchus xylophilus, is a mycophagous and phytophagous pathogen responsible for the current widespread epidemic of the pine wilt disease, which has become a major threat to pine forests throughout the world. Despite the availability of several preventive trunk-injection agents, no therapeutic trunk-injection agent for eradication of PWN currently exists. In the characterization of basic physiological properties of B. xylophilus YB-1 isolates, we established a high-throughput screening (HTS) method that identifies potential hits within approximately 7 h. Using this HTS method, we screened 206 compounds with known activities, mostly antifungal, for antinematodal activities and identified HWY-4213 (1-n-undecyl-2-[2-fluorphenyl] methyl-3,4-dihydro-6,7-dimethoxy-isoquinolinium chloride), a highly water-soluble protoberberine derivative, as a potent nematicidal and antifungal agent. When tested on 4 year-old pinewood seedlings that were infected with YB-1 isolates, HWY-4213 exhibited a potent therapeutic nematicidal activity. Further tests of screening 39 Caenorhabditis elegans mutants deficient in channel proteins and B. xylophilus sensitivity to Ca2+ channel blockers suggested that HWY-4213 targets the calcium channel proteins. Our study marks a technical breakthrough by developing a novel HTS method that leads to the discovery HWY-4213 as a dual-acting antinematodal and antifungal compound

    Study on Nucleation Kinetics of Lysozyme Crystallization

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    The nucleation kinetics of hen egg-white lysozyme crystallization was investigated using a hot stage cooling crystallizer and a microscope to monitor the solution crystallization process in real time. Images of crystals were continuously recorded under varied precipitant and protein concentrations. The nucleation rate was found to be higher at higher precipitant concentration, and increase monotonically with protein concentration if the precipitant concentration was held constant. Attempt was made to interpret the experimental data using classical nucleation theory. It was found that the model predictions are lower than the experimental values at low supersaturations but agree well with experimental data at high supersaturations. The trends in the experimental data suggest that two nucleation mechanisms might co-exist: heterogeneous nucleation seeming to be the dominant at low supersaturation while at higher supersaturation homogeneous nucleation seeming to play the major role

    Hypoglycemic effects of Welsh onion in an animal model of diabetes mellitus

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    Tight control of blood glucose is the most important strategy for the treatment of diabetes mellitus. Here, we investigated the beneficial effects of Welsh onion on fasting and postprandial hyperglycemia. Inhibitory activities of hot water extracts from the green stalk and white bulb, which are the edible portions of the Welsh onion, and the fibrous root extract against yeast Ξ±-glucosidase were measured in vitro. To study the effects of Welsh onion on postprandial hyperglycemia, a starch solution (1 g/kg) with and without Welsh onion fibrous root extract (500 mg/kg) or acarbose (50 mg/kg) was administered to streptozotocin-induced diabetic rats after an overnight fast. Postprandial plasma glucose levels were measured and incremental areas under the response curve were calculated. To study the hypoglycemic effects of chronic feeding of Welsh onion, five-week-old db/db mice were fed an AIN-93G diet or a diet containing either Welsh onion fibrous root extract at 0.5% or acarbose at 0.05% for 7 weeks after 1 week of adaptation. Fasting plasma glucose and blood glycated hemoglobin were measured. Compared to the extract from the edible portions of Welsh onion, the fibrous root extract showed stronger inhibition against yeast Ξ±-glucosidase, with an IC50 of 239 Β΅g/mL. Oral administration of Welsh onion fibrous root extract (500 mg/kg) and acarbose (50 mg/kg) significantly decreased incremental plasma glucose levels 30-120 min after oral ingestion of starch as well as the area under the postprandial glucose response curve, compared to the control group (P < 0.01). The plasma glucose and blood glycated hemoglobin levels of the Welsh onion group were significantly lower than those of the control group (P < 0.01), and were not significantly different from those fed acarbose. Thus, we conclude that the fibrous root of Welsh onion is effective in controlling hyperglycemia in animal models of diabetes mellitus

    Design of chimeric GLP-1A using oligomeric bile acids to utilize transporter-mediated endocytosis for oral delivery

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    Background Despite the effectiveness of glucagon-like peptide-1 agonist (GLP-1A) in the treatment of diabetes, its large molecular weight and high hydrophilicity result in poor cellular permeability, thus limiting its oral bioavailability. To address this, we developed a chimeric GLP-1A that targets transporter-mediated endocytosis to enhance cellular permeability to GLP-1A by utilizing the transporters available in the intestine, particularly the apical sodium-dependent bile acid transporter (ASBT). Methods In silico molecular docking and molecular dynamics simulations were used to investigate the binding interactions of mono-, bis-, and tetra-deoxycholic acid (DOCA) (monoDOCA, bisDOCA, and tetraDOCA) with ASBT. After synthesizing the chimeric GLP-1A-conjugated oligomeric DOCAs (mD-G1A, bD-G1A, and tD-G1A) using a maleimide reaction, in vitro cellular permeability and insulinotropic effects were assessed. Furthermore, in vivo oral absorption in rats and hypoglycemic effect on diabetic db/db mice model were evaluated. Results In silico results showed that tetraDOCA had the lowest interaction energy, indicating high binding affinity to ASBT. Insulinotropic effects of GLP-1A-conjugated oligomeric DOCAs were not different from those of GLP-1A-Cys or exenatide. Moreover, bD-G1A and tD-G1A exhibited improved in vitro Caco-2 cellular permeability and showed higher in vivo bioavailability (7.58% and 8.63%) after oral administration. Regarding hypoglycemic effects on db/db mice, tD-G1A (50 ΞΌg/kg) lowered the glucose level more than bD-G1A (50 ΞΌg/kg) compared with the control (35.5% vs. 26.4%). Conclusion GLP-1A was conjugated with oligomeric DOCAs, and the resulting chimeric compound showed the potential not only for glucagon-like peptide-1 receptor agonist activity but also for oral delivery. These findings suggest that oligomeric DOCAs can be used as effective carriers for oral delivery of GLP-1A, offering a promising solution for enhancing its oral bioavailability and improving diabetes treatment.This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (grant nos. 2020R1A2C1102831, 2022R1A5A8033794, 2022R1A4A3034038). This study was also supported by Regional Innovation Strategy (RIS) through the NRF funded by the Ministry of Education (MOE) (2021RIS-001

    Ovarian Cancer during Pregnancy: Clinical and Pregnancy Outcome

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    The aim of this study is to evaluate the clinical feature and pregnancy outcome in patients with ovarian cancer diagnosed during pregnancy. We retrospectively analyzed the medical records of 27 patients diagnosed with ovarian cancer during pregnancy at Cheil General Hospital & Women's Healthcare Center from January 1996 to December 2006. Mean age of the patients was 29.1 yr (range 23-40), and a mean follow-up period was 57 months (range 7-112 months). Of 27 patients, 15 (55.5%) had borderline malignancies, 7 (25.9%) had epithelial malignancies and 5 (18.6%) had germ cell tumors. A total of 26 patients received a conservative surgery preserving pregnancy. The mean time for surgical intervention during pregnancy was 20 weeks of gestational age. Of the 27 patients, 26 had full term delivery of a healthy baby without any congenital malformation. Only one patient with epithelial ovarian cancer had a relapse at 19 months after the first conservative operation with adjuvant chemotherapy. There were few data for managing patients with ovarian cancer diagnosed during pregnancy. This study results could help establish a guideline for management of ovarian malignancy complicating pregnancy

    Results of Colorectal Cancer Screening of the National Cancer Screening Program in Korea, 2008

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    PURPOSE: This study aims to investigate the current situation of national colorectal cancer screening by analyzing participation rates, positive rates of screening methods and screening rate of secondary screening tests in colorectal screening of the national cancer screening program in 2008.0aMATERIALS AND METHODS: With database about target population and screened individuals of the national cancer screening program, the results of target population and participants of colorectal cancer screening in 2008 were analyzed. Among adults aged over 50 years of medical aid and beneficiaries of national health insurance paying lower 50% premiums in the total subscribers, 4,640,365 were target population of colorectal cancer screening and the data of 984,915 undergoing fecal occult blood test (FOBT) as a primary screening were analyzed.0aRESULTS: The colorectal cancer screening rate was 21.2% and the rates of national health insurance subscribers, females and the elderly aged 60-64 years were higher than those of others. The recipients with a positive result in FOBT recorded approximately 7.5%. Medical aid beneficiaries (7.9%), males (8.8%) and seniors aged over 75 years (9.1%) showed higher positive rates than the average one. Out of the FOBT positive recipients, 43.0% took a secondary screening and the rate undergoing colonoscopy (31.4%) was higher than that of doing double-contrast barium enema test (11.6%).0aCONCLUSION: Colorectal cancer screening rate of medical aid beneficiaries and people paying lower 50% premiums among national health insurance subscribers, was different according to demographic characters (gender, age and types of health insurance). This finding meant that screening for the vulnerable needed to be encouraged by considering socio-demographic characters. Additionally, more efforts were necessary to increase the secondary screening rate of people with a positive result in primary one.ope

    Clinical Outcomes of Patients treated for Cervical Pregnancy with or without Methotrexate

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    The objective of this study is to describe the clinical outcomes of patients treated for cervical pregnancy with or without methotrexate (MTX) and to evaluate the effects of MTX in the treatment of cervical pregnancy. Between January 1993 and February 2000, 31 patients were diagnosed with cervical pregnancy. Twenty-two patients were treated with MTX chemotherapy and nine patients were treated with surgical procedures without MTX treatment. In the non-MTX treatment group, three patients underwent total abdominal hysterectomy, five required adjuvant procedures to control the bleeding during dilatation and curettage (D&C) and only one patient was treated with a simple D&C. In the MTX treatment group, fourteen (63.6%) patients were treated with only MTX and eight (36.4%) cases underwent concomitant procedures (simple curettage, curettage and Foley catheter tamponade, cervical cerclage, ligation of the descending branches of uterine arteries, or ligation of hypogastric arteries). The uterus was preserved in all cases and three women delivered healthy babies in their subsequent pregnancy. In conclusion, early diagnosis, appropriate MTX regimen in combination of necessary adjuvant conservative procedures could contribute to successful treatment with preservation of the uterus and future reproductive ability

    Inhibitory activity of Euonymus alatus against alpha-glucosidase in vitro and in vivo

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    The major goal in the treatment of diabetes mellitus is to achieve near-normal glycemic control. To optimize both fasting blood glucose and postprandial glucose levels is important in keeping blood glucose levels as close to normal as possible. Ξ±-Glucosidase is the enzyme that digests dietary carbohydrate, and inhibition of this enzyme could suppress postprandial hyperglycemia. The purpose of this study was to test the inhibitory activity of methanol extract of Euonymus alatus on Ξ±-glucosidase in vitro and in vivo to evaluate its possible use as an anti-diabetic agent. Yeast Ξ±-glucosidase inhibitory activities of methanol extract of E. alatus were measured at concentrations of 0.50, 0.25, 0.10, and 0.05 mg/ml. The ability of E. alatus to lower postprandial glucose was studied in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without E. alatus extract (500 mg/kg) was administered to diabetic rats by gastric intubation after an overnight fast. Plasma glucose levels were measured at 30, 60, 90, 120, 180, and 240 min. Plasma glucose levels were expressed in increments from baseline, and incremental areas under the response curve were calculated. Extract of E. alatus,which had an IC50 value of 0.272 mg/ml, inhibited yeast Ξ±-glucosidase activity in a concentration-dependent manner. A single oral dose of E. alatus extract significantly inhibited increases in blood glucose levels at 60 and 90 min (p<0.05) and significantly decreased incremental response areas under the glycemic response curve (p<0.05). These results suggest that E. alatus has an antihyperglycemic effect by inhibiting Ξ±-glucosidase activity in this animal model of diabetes mellitus

    Three-Dimensional and Chemical Mapping of Intracellular Signaling Nanodomains in Health and Disease with Enhanced Expansion Microscopy

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    Nanodomains are intracellular foci which transduce signals between major cellular compartments. One of the most ubiquitous signal transducers, the ryanodine receptor (RyR) calcium channel, is tightly clustered within these nanodomains. Super-resolution microscopy has previously been used to visualize RyR clusters near the cell surface. A majority of nanodomains located deeper within cells have remained unresolved due to limited imaging depths and axial resolution of these modalities. A series of enhancements made to expansion microscopy allowed individual RyRs to be resolved within planar nanodomains at the cell periphery and the curved nanodomains located deeper within the interiors of cardiomyocytes. With a resolution of ∼ 15 nm, we localized both the position of RyRs and their individual phosphorylation for the residue Ser2808. With a three-dimensional imaging protocol, we observed disturbances to the RyR arrays in the nanometer scale which accompanied right-heart failure caused by pulmonary hypertension. The disease coincided with a distinct gradient of RyR hyperphosphorylation from the edge of the nanodomain toward the center, not seen in healthy cells. This spatial profile appeared to contrast distinctly from that sustained by the cells during acute, physiological hyperphosphorylation when they were stimulated with a β-adrenergic agonist. Simulations of RyR arrays based on the experimentally determined channel positions and phosphorylation signatures showed how the nanoscale dispersal of the RyRs during pathology diminishes its intrinsic likelihood to ignite a calcium signal. It also revealed that the natural topography of RyR phosphorylation could offset potential heterogeneity in nanodomain excitability which may arise from such RyR reorganization

    Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza

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    The ectodomain of matrix protein 2 (M2e) of influenza A virus is a rationale target antigen candidate for the development of a universal vaccine against influenza as M2e undergoes little sequence variation amongst human influenza A strains. Vaccine-induced M2e-specific antibodies (Abs) have been shown to display significant cross-protective activity in animal models. M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study, we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored.A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs.The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections
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