598 research outputs found
6,7-Dimethoxy-4-methylcoumarin suppresses pro-inflammatory mediator expression through inactivation of the NF-kappaB and MAPK pathways in LPS-induced RAW 264.7 cells
In this study, we investigated the ability of 6,7-dimethoxy-4-methylcoumarin (DMC) to inhibit lipopolysaccharide (LPS)-induced expression of pro-inflammatory mediators in mouse macrophage (RAW 264.7) cells, and the molecular mechanism through which this inhibition occurred. Our results indicated that DMC down regulated LPS-induced nitric oxide (NO) synthase (iNOS) and cyclooxygenase-2 (COX-2) expression, thereby reducing the production of NO and prostaglandin E2 (PGE2) in LPS-activated RAW 264.7 cells. Furthermore, DMC suppressed LPS-induced production of pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. To elucidate the mechanism underlying the anti-
inflammatory activity of DMC, we assessed its effects on the mitogen-activated protein kinase (MAPK) pathway and the activity and expression of nuclear transcription factor kappa-B (NF-κB). The experiments demonstrated that DMC inhibited LPS-induced phosphorylation of extracellular signal-regulated kinases (ERKs), c-Jun N-terminal kinase (JNK), and p38. In addition, it attenuated LPS-induced NF-κB activation via the inhibition of IκB-α phosphorylation. Taken together, these data suggest that DMC exerts its anti-inflammatory effects in RAW 264.7 cells through the inhibition of LPS-stimulated NF-κB and MAPK signaling, thereby downregulating the expression of pro-inflammatory mediators
Strain-gradient-induced magnetic anisotropy in straight-stripe mixed-phase bismuth ferrites: An insight into flexomagnetic phenomenon
Implementation of antiferromagnetic compounds as active elements in
spintronics has been hindered by their insensitive nature against external
perturbations which causes difficulties in switching among different
antiferromagnetic spin configurations. Electrically-controllable strain
gradient can become a key parameter to tune the antiferromagnetic states of
multiferroic materials. We have discovered a correlation between an
electrically-written straight-stripe mixed-phase boundary and an in-plane
antiferromagnetic spin axis in highly-elongated La-5%-doped BiFeO thin
films by performing polarization-dependent photoemission electron microscopy in
conjunction with cluster model calculations. Model Hamiltonian calculation for
the single-ion anisotropy including the spin-orbit interaction has been
performed to figure out the physical origin of the link between the strain
gradient present in the mixed phase area and its antiferromagnetic spin axis.
Our findings enable estimation of the strain-gradient-induced magnetic
anisotropy energy per Fe ion at around 510 eV m, and provide a
new pathway towards an electric-field-induced 90 rotation of
antiferromagnetic spin axis at room temperature by flexomagnetism.Comment: 32 pages, 5 figure
Pediatric Radiofrequency Catheter Ablation: Results of Initial 100 Consecutive Cases Including Congenital Heart Anomalies
Radiofrequency catheter ablation (RFCA) has recently become a management option for pediatric tachycardia. We reviewed the records of a total of 100 patients (aged 10 months to 19 yr) who had undergone RFCA, from March 2000 to June 2004. Types of arrhythmia (age, acute success rate) were as follows: atrioventricular reentrant tachycardia (AVRT, 9.0±3.7 yr, 66/67), atrioventricular nodal reentrant tachycardia (AVNRT, 13±2.5 yr, 16/16), ectopic atrial tachycardia (6.4±3.3 yr, 5/5), junctional ectopic tachycardia (10 month, 1/1), ventricular tachycardia (12±4.9 yr, 6/6), postsurgical intraatrial reentrant tachycardia (15.6±4.1 yr, 2/3), twin node tachycardia (4 yr, 0/1), and His bundle ablation (9 yr, 1/1). The age of AVNRT was older than that of AVRT (p=0.002). Associated cardiac disease was detected in 17 patients, including 6 univentricular patients, and 3 Ebstein's anomaly patients. RFCA for multiple accessory pathways required longer fluoroscopic times than did the single accessory pathway (53.9±4.8 vs. 36.2±24.1 min; p=0.03), and was associated with a higher recurrence rate (3/9 vs. 3/53; p=0.03). Regardless of the presence or absence of cardiac diseases, the overall acute success rate was 97% without major complications, the recurrence rate was 8.2%, and the final success rate was 97%. This experience confirmed the efficacy and safety of RFCA in the management of tachycardia
in children
Inducible and Reversible Clock Gene Expression in Brain Using the tTA System for the Study of Circadian Behavior
The mechanism of circadian oscillations in mammals is cell autonomous and is generated by a set of genes that form a transcriptional autoregulatory feedback loop. While these “clock genes” are well conserved among animals, their specific functions remain to be fully understood and their roles in central versus peripheral circadian oscillators remain to be defined. We utilized the in vivo inducible tetracycline-controlled transactivator (tTA) system to regulate Clock gene expression conditionally in a tissue-specific and temporally controlled manner. Through the use of Secretogranin II to drive tTA expression, suprachiasmatic nucleus– and brain-directed expression of a tetO::Clock(Δ19) dominant-negative transgene lengthened the period of circadian locomotor rhythms in mice, whereas overexpression of a tetO::Clock(wt) wild-type transgene shortened the period. Low doses (10 μg/ml) of doxycycline (Dox) in the drinking water efficiently inactivated the tTA protein to silence the tetO transgenes and caused the circadian periodicity to return to a wild-type state. Importantly, low, but not high, doses of Dox were completely reversible and led to a rapid reactivation of the tetO transgenes. The rapid time course of tTA-regulated transgene expression demonstrates that the CLOCK protein is an excellent indicator for the kinetics of Dox-dependent induction/repression in the brain. Interestingly, the daily readout of circadian period in this system provides a real-time readout of the tTA transactivation state in vivo. In summary, the tTA system can manipulate circadian clock gene expression in a tissue-specific, conditional, and reversible manner in the central nervous system. The specific methods developed here should have general applicability for the study of brain and behavior in the mouse
Korean adolescents' perceptions of nutrition and health towards fast foods in Busan area
Adolescents in Busan area were asked in a survey about their perception and attitudes towards fast food. Most respondents answered that they consume fast food once a month because it is fast, easily accessible and tasty. Although they perceived fast food as unhealthy and less nutritious, they were less aware of its effect on their health and nutritional status. The more knowledgeable respondents were about nutrition and health the less likely they were to choose fast food over other meals. However, respondents who had little or no knowledge about the nutritional factors of fast food accounted for 43.1%. As to their source of dietary information, students relied on themselves (31.0%), parents (20.5%) and friends (19.9%). The medium through which students got the most nutrition and health information was television (66.8%), followed by the Internet (36.7%) and magazines (29.7%). This study will enable educators to plan more effective strategies for improving the dietary knowledge of the adolescent population
The invasive lobular carcinoma as a prototype luminal A breast cancer: A retrospective cohort study
<p>Abstract</p> <p>Background</p> <p>Although the invasive lobular carcinoma (ILC) is the second most frequent histologic subtype in Western countries, its incidence is much lower in Asia, and its characteristics are less well known.</p> <p>Methods</p> <p>We assessed the clinical characteristics and outcomes of 83 Korean patients (2.8%) with ILC for comparison with 2,833 (97.2%) with the invasive ductal carcinoma (IDC), including 1,088 (37.3%) with the luminal A subtype (LA-IDC).</p> <p>Results</p> <p>The mean age of all patients was 48.2 years, with no significant differences among the groups. Compared to IDC, ILC showed a larger tumor size (≥T2, 59.8% vs. 38.8%, <it>P </it>= 0.001), a lower histologic grade (HG 1/2, 90.4% vs. 64.4%, <it>P </it>< 0.001), more frequent estrogen receptor positive (90.4% vs. 64.4%, <it>P </it>< 0.001), progesterone receptor positive (71.1% vs. 50.1%, <it>P </it>< 0.001) and HER2 negative (97.5% vs. 74.6%, <it>P </it>< 0.001) status, and lower Ki-67 expression (10.3% ± 10.6% vs. 20.6% ± 19.8%, <it>P </it>< 0.001), as well as being more likely to be of the luminal A subtype (91.4% vs. 51.2%, <it>P </it>< 0.001). Six (7.2%) ILC and 359 (12.7%) IDC patients developed disease recurrence, with a median follow-up of 56.4 (range 4.9-136.6) months. The outcome of ILC was close to LA-IDC (HR 0.77 for recurrence, 95% CI 0.31-1.90, <it>P </it>= 0.57; HR 0.75 for death, 95% CI 0.18-3.09, <it>P </it>= 0.70) and significantly better than for the non-LA-IDC (HR 1.69 for recurrence, 95% CI 1.23-2.33, <it>P </it>= 0.001; HR 1.50 for death, 95% CI 0.97-2.33, <it>P </it>= 0.07).</p> <p>Conclusions</p> <p>ILC, a rare histologic type of breast cancer in Korea, has distinctive clinicopathological characteristics similar to those of LA-IDC.</p
Enzymatic synthesis of chlorogenic acid glucoside using dextransucrase and its physical and functional properties
Chlorogenic acid, a major polyphenol in edible plants, possesses strong antioxidant activity, anti-lipid peroxidation and anticancer effects. It used for industrial applications; however, this is limited by its instability to heat or light. In this study, we, for the first time synthesized chlorogenic acid glucoside (CHG) via transglycosylation using dextransucrase from Leuconostoc mesenteroides and sucrose. CHG was purified and its structure determined by nuclear magnetic resonance and matrix-associated laser desorption ionization–time-of-flight mass spectroscopy. The production yield of CHG was 44.0% or 141 mM, as determined by response surface methodology. CHG possessed a 65% increase in water solubility and a 2-fold browning resistance and it displayed stronger inhibition of lipid peroxidation and of colon cancer cell growth by MTT assay, compared to chlorogenic acid. Therefore, this study may expand the industrial applications of chlorogenic acid as water-soluble or browning resistant compound (CHG) through enzymatic glycosylation
Development and Clinical Evaluation of a Rapid Serodiagnostic Test for Toxoplasmosis of Cats Using Recombinant SAG1 Antigen
Rapid serodiagnostic methods for Toxoplasma gondii infection in cats are urgently needed for effective control of transmission routes toward human infections. In this work, 4 recombinant T. gondii antigens (SAG1, SAG2, GRA3, and GRA6) were produced and tested for the development of rapid diagnostic test (RDT). The proteins were expressed in Escherichia coli, affinity-purified, and applied onto the nitrocellulose membrane of the test strip. The recombinant SAG1 (rSAG1) showed the strongest antigenic activity and highest specificity among them. We also performed clinical evaluation of the rSAG1-loaded RDT in 182 cat sera (55 household and 127 stray cats). The kit showed 0.88 of kappa value comparing with a commercialized ELISA kit, which indicated a significant correlation between rSAG1-loaded RDT and the ELISA kit. The overall sensitivity and specificity of the RDT were 100% (23/23) and 99.4% (158/159), respectively. The rSAG1-loaded RDT is rapid, easy to use, and highly accurate. Thus, it would be a suitable diagnostic tool for rapid detection of antibodies in T. gondii-infected cats under field conditions
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