1,799 research outputs found

    A Thiazole Orange Derivative Targeting the Bacterial Protein FtsZ Shows Potent Antibacterial Activity.

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    The prevalence of multidrug resistance among clinically significant bacteria calls for the urgent development of new antibiotics with novel mechanisms of action. In this study, a new small molecule exhibiting excellent inhibition of bacterial cell division with potent antibacterial activity was discovered through cell-based screening. The compound exhibits a broad spectrum of bactericidal activity, including the methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus and NDM-1 Escherichia coli. The in vitro and in vivo results suggested that this compound disrupts the dynamic assembly of FtsZ protein and Z-ring formation through stimulating FtsZ polymerization. Moreover, this compound exhibits no activity on mammalian tubulin polymerization and shows low cytotoxicity on mammalian cells. Taken together, these findings could provide a new chemotype for development of antibacterials with FtsZ as the target

    Correlation of the composite equilibrium score of computerized dynamic posturography and clinical balance tests

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    AbstractBackgroundThe computerized dynamic posturography has been widely used to access balance control in patients with balance dysfunction. A composite-equilibrium score (CS) can be calculated from the sensory organization test using the computerized dynamic posturography. However, the correlation between the composite equilibrium score and clinical tests and its ability to predict falls has rarely been explored in the past.MethodsA total of 60 patients with chief complaint of dizziness were enrolled in our study, and clinical assessments were done including the sensory organization test (SOT), Timed Up and Go test (TUG), Tinetti Performance-Oriented Mobility Assessment (POMA), and the dynamic gait index (DGI). The age and the subjective feeling of the severity of dizziness quantified by the visual analog scale (VAS) of each patient were also recorded.ResultsStatistical analysis revealed significant correlation between the composite equilibrium score and the TUG, POMA (gait, balance and total scores), and the DGI. However, there is statistically significant correlation between neither the CS and the age nor the VAS of dizziness. When grouping the DGI, POMA (total score), and the TUG cutoff to predict fall risks, the correlations to the CS can still be established except the TUG.ConclusionFrom the results of our study, the validity of the clinical tests was established in assessment of balance function, and clinicians can utilize these tools for preliminary evaluation of patient balance when computerized dynamic posturography is not available. In addition, CS can be used to predict the risk of falls

    Glycogen synthase kinase 3α and 3β have distinct functions during cardiogenesis of zebrafish embryo

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    <p>Abstract</p> <p>Background</p> <p>Glycogen synthase kinase 3 (GSK3) encodes a serine/threonine protein kinase, is known to play roles in many biological processes. Two closely related GSK3 isoforms encoded by distinct genes: GSK3α (51 kDa) and GSK3β (47 kDa). In previously studies, most GSK3 inhibitors are not only inhibiting GSK3, but are also affecting many other kinases. In addition, because of highly similarity in amino acid sequence between GSK3α and GSK3β, making it difficult to identify an inhibitor that can be selective against GSK3α or GSK3β. Thus, it is relatively difficult to address the functions of GSK3 isoforms during embryogenesis. At this study, we attempt to specifically inhibit either GSK3α or GSK3β and uncover the isoform-specific roles that GSK3 plays during cardiogenesis.</p> <p>Results</p> <p>We blocked <it>gsk3α </it>and <it>gsk3β </it>translations by injection of morpholino antisense oligonucleotides (MO). Both <it>gsk3α</it>- and <it>gsk3β</it>-MO-injected embryos displayed similar morphological defects, with a thin, string-like shaped heart and pericardial edema at 72 hours post-fertilization. However, when detailed analysis of the <it>gsk3α</it>- and <it>gsk3β</it>-MO-induced heart defects, we found that the reduced number of cardiomyocytes in <it>gsk3α </it>morphants during the heart-ring stage was due to apoptosis. On the contrary, <it>gsk3β </it>morphants did not exhibit significant apoptosis in the cardiomyocytes, and the heart developed normally during the heart-ring stage. Later, however, the heart positioning was severely disrupted in <it>gsk3β </it>morphants. <it>bmp4 </it>expression in <it>gsk3β </it>morphants was up-regulated and disrupted the asymmetry pattern in the heart. The cardiac valve defects in <it>gsk3β </it>morphants were similar to those observed in <it>axin1 </it>and <it>apc</it><sup><it>mcr </it></sup>mutants, suggesting that GSK3β might play a role in cardiac valve development through the Wnt/β-catenin pathway. Finally, the phenotypes of <it>gsk3α </it>mutant embryos cannot be rescued by <it>gsk3β </it>mRNA, and vice versa, demonstrating that GSK3α and GSK3β are not functionally redundant.</p> <p>Conclusion</p> <p>We conclude that (1) GSK3α, but not GSK3β, is necessary in cardiomyocyte survival; (2) the GSK3β plays important roles in modulating the left-right asymmetry and affecting heart positioning; and (3) GSK3α and GSK3β play distinct roles during zebrafish cardiogenesis.</p

    Role of apamin sensitive small conductance calcium-activated potassium currents in long term cardiac memory in rabbits

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    Background Apamin-sensitive small conductance calcium-activated K current (IKAS) is upregulated during ventricular pacing and masks short-term cardiac memory (CM). Objective – To determine the role of IKAS in long-term CM. Methods – CM was created with 3-5 weeks of ventricular pacing and defined by a flat or inverted T-wave off pacing. Epicardial optical mapping was performed in both paced and normal ventricles. Action potential duration (APD80) was determined during RA pacing. Ventricular stability was tested before and after IKAS blockade. Four paced hearts and 4 normal hearts were used for western blotting and histology. Results – There were no significant differences in either the echocardiographic parameters or in fibrosis levels between groups. Apamin induced more APD80 prolongation in CM than in normal ventricles (9.6% [8.8%-10.5%] vs 3.1% [1.9%-4.3%], p<0.001). Apamin significantly lengthend the APD80 in the CM model at late activation sites, indicating significant IKAS upregulation at those sites. The CM model also had altered Ca2+ handling as the 50% Ca2+ transient duration and amplitude were increased at distal sites compared to a proximal site (near the pacing site). After apamin, the CM model had increased VF inducibility (paced vs control, 33/40 (82.5%) vs 7/20 (35%) P<0.001), and longer VF durations (124 vs 26 seconds, P<0.001). Conclusions Chronic ventricular pacing increases Ca2+ transients at late activation sites which activates IKAS to maintain repolarization reserve. IKAS blockade increases VF vulnerability in chronically paced rabbit ventricles

    Gender Difference in Statin Intervention on Blood Lipid Control among Patients with Coronary Heart Disease

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    SummaryBackgroundThe aim of this study was to clarify the current status in the effective control of dyslipidemia in Taiwanese women and men with coronary heart disease (CHD).Materials and methodsA total 1584 patients with CHD (1188 men, aged 64.8 ± 11.6 years and 396 women, aged 69.0 ± 9.8 years) from 3486 patients who had atherosclerotic vascular disease and complete lipids measured values [total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C)] were used for analysis.ResultsThe waist, height, weight, and creatinine levels were higher in men than in women. The systolic blood pressure, TC, HDL-C, LDL-C, fasting blood glucose, and platelet were lower in men than in women. Men were more likely to achieve the target goal than women in TC < 160 mg/dL, LDL-C < 100 mg/dL, and TG < 150 mg/dL as well as to achieve HDL-C goal.ConclusionA significant gap was found between the guidelines and clinical practice in statin intervention among these CHD patients, particularly for women. The strategy in control of dyslipidemia should consider gender difference

    Association of Female Menopause With Atrioventricular Mechanics and Outcomes

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    BACKGROUND: Despite known sex differences in cardiac structure and function, little is known about how menopause and estrogen associate with atrioventricular mechanics and outcomes. OBJECTIVE: To study how, sex differences, loss of estrogen in menopause and duration of menopause, relate to atrioventricular mechanics and outcomes. METHODS: Among 4051 asymptomatic adults (49.8 ± 10.8 years, 35%women), left ventricular (LV) and left atrial (LA) mechanics were assessed using speckle-tracking. RESULTS: Post-menopausal (vs. pre-menopausal) women had similar LV ejection fraction but reduced GLS, reduced PALS, increased LA stiffness, higher LV sphericity and LV torsion (all p < 0.001). Multivariable analysis showed menopause to be associated with greater LV sphericity (0.02, 95%CI 0.01, 0.03), higher indexed LV mass (LVMi), lower mitral e’, lower LV GLS (0.37, 95%CI 0.04–0.70), higher LV torsion, larger LA volume, worse PALS (∼2.4-fold) and greater LA stiffness (0.028, 95%CI 0.01–0.05). Increasing years of menopause was associated with further reduction in GLS, markedly worse LA mechanics despite greater LV sphericity and higher torsion. Lower estradiol levels correlated with more impaired LV diastolic function, impaired LV GLS, greater LA stiffness, and increased LV sphericity and LV torsion (all p < 0.05). Approximately 5.5% (37/669) of post-menopausal women incident HF over 2.9 years of follow-up. Greater LV sphericity [adjusted hazard ratio (aHR) 1.04, 95%CI 1.00–1.07], impaired GLS (aHR 0.87, 95%CI 0.78–0.97), reduced peak left atrial longitudinal strain (PALS, aHR 0.94, 95%CI 0.90–0.99) and higher LA stiffness (aHR 10.5, 95%CI 1.69–64.6) were independently associated with the primary outcome of HF hospitalizations in post-menopause. Both PALS < 23% (aHR:1.32, 95%CI 1.01–3.49) and GLS < 16% (aHR:5.80, 95%CI 1.79–18.8) remained prognostic for the incidence of HF in post-menopausal women in dichotomous analyses, even after adjusting for confounders. Results were consistent with composite outcomes of HF hospitalizations and 1-year all-cause mortality as well. CONCLUSION: Menopause was associated with greater LV/LA remodeling and reduced LV longitudinal and LA function in women. The cardiac functional deficit with menopause and lower estradiol levels, along with their independent prognostic value post-menopause, may elucidate sex differences in heart failure further

    The optimal pulse pressures for healthy adults with different ages and sexes correlate with cardiovascular health metrics

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    BackgroundPulse pressure (PP) may play a role in the development of cardiovascular disease, and the optimal PP for different ages and sexes is unknown. In a prospective cohort, we studied subjects with favorable cardiovascular health (CVH), proposed the mean PP as the optimal PP values, and demonstrated its relationship with healthy lifestyles.Methods and resultsBetween 1996 and 2016, a total of 162,636 participants (aged 20 years or above; mean age 34.9 years; 26.4% male subjects; meeting criteria for favorable health) were recruited for a medical examination program. PP in male subjects was 45.6 ± 9.4 mmHg and increased after the age of 50 years. PP in female subjects was 41.8 ± 9.5 mmHg and increased after the age of 40 years, exceeding that of male subjects after the age of 50 years. Except for female subjects with a PP of 40–70 mmHg, PP increase correlates with both systolic blood pressure (BP) increase and diastolic BP decrease. Individuals with mean PP values are more likely to meet health metrics, including body mass index (BMI) &lt;25 kg/m2 (chi-squared = 9.35, p&lt;0.01 in male subjects; chi-squared = 208.79, p &lt; 0.001 in female subjects) and BP &lt;120/80 mmHg (chi-squared =1,300, p &lt; 0.001 in male subjects; chi-squared =11,000, p &lt; 0.001 in female subjects). We propose a health score (Hscore) based on the sum of five metrics (BP, BMI, being physically active, non-smoking, and healthy diet), which significantly correlates with the optimal PP.ConclusionThe mean PP (within ±1 standard deviation) could be proposed as the optimal PP in the adult population with favorable CVH. The relationship between health metrics and the optimal PP based on age and sex was further demonstrated to validate the Hscore

    MST4 Phosphorylation of ATG4B Regulates Autophagic Activity, Tumorigenicity, and Radioresistance in Glioblastoma

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    ATG4B stimulates autophagy by promoting autophagosome formation through reversible modification of ATG8. We identify ATG4B as a substrate of mammalian sterile20-like kinase (STK) 26/MST4. MST4 phosphorylates ATG4B at serine residue 383, which stimulates ATG4B activity and increases autophagic flux. Inhibition of MST4 or ATG4B activities using genetic approaches or an inhibitor of ATG4B suppresses autophagy and the tumorigenicity of glioblastoma (GBM) cells. Furthermore, radiation induces MST4 expression, ATG4B phosphorylation, and autophagy. Inhibiting ATG4B in combination with radiotherapy in treating mice with intracranial GBM xenograft markedly slows tumor growth and provides a significant survival benefit. Our work describes an MST4-ATG4B signaling axis that influences GBM autophagy and malignancy, and whose therapeutic targeting enhances the anti-tumor effects of radiotherapy., • MST4 kinase regulates the growth, sphere formation, and tumorigenicity of GBM cells • MST4 stimulates autophagy by activating ATG4B through phosphorylation of ATG4B S383 • Radiation increases MST4 expression and ATG4B phosphorylation, inducing autophagy • Inhibiting ATG4B enhances the anti-tumor effects of radiotherapy in GBM PDX models , Huang et al. show that radiation induces MST4 expression and that MST4 phosphorylates ATG4B at serine 383, which increases ATG4B activity and autophagic flux. Inhibition of ATG4B reduces autophagy and tumorigenicity of glioblastoma (GBM) cells and improves the impact of radiotherapy on GBM growth in mice
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