Anti-inflammatory Effect of Quercetin on Picryl Chloride-induced Contact Dermatitis in BALB/c Mice / 한국실험동물학회지

In this study, we investigated that anti-inflammatory effect of quercetin on picryl chloride(PCL)-induced contact dermatitis in BALB/c Mice. Experimental animals were divided into three groups and comprising five animals. All groups of oral administration was begun on the first day of PCL treatment and ceased on day 5. For the induction of contact dermatitis, BALB/c mice were sensitized with 40 microliter of 1.5% picryl choloride (PCL) to the left and right ear, respectively. Ear swelling responses were much weaker in high-dose group (100 mg/kg) than control group (0 mg/kg). Total serum IgE levels and histamine levels were measured by sandwich ELISA method using mouse IgE, histamine measuring Kit. Both total serum IgE and histamine levels were significantly decreased in high-dose group (100 mg/kg) than other groups. Degranulation of mast cells were also confirmed by Toluidine Blue (TB) staining method. In high-dose group (100 mg/kg), the number of mast cells were significantly decreased and there are many mast cells were shown degranulation in control group (0 mg/kg). All of these results demonstrate that the pharmacological actions of quercetin indicate their potential activity for allergic inflammatory diseases through the down-regulation of mast cell activation.

TNF-alpha upregulates PTEN via NF-kappaB signaling pathways in human leukemic cells

TNF-alpha plays a variety of biological functions such as apoptosis, inflammation and immunity. PTEN also has various cellular function including cell growth, proliferation, migration and differentiation. Thus, possible relationships between the two molecules are suggested. TNF-alpha has been known to downregulate PTEN via NF-kappaB pathway in the human colon cell line, HT-29. However, here we show the opposite finding that TNF-alpha upregulates PTEN via activation of NF-kappaB in human leukemic cells. TNF-alpha increased PTEN expression at HL-60 cells in a time- and dose-dependent manner, but the response was abolished by disruption of NF-kappaB with p65 anisense phosphorothioate oligonucleotide or pyrrolidine dithiocarbamate. We found that TNF-alpha activated the NF-kappaB pathways, evidenced by the translocation of p65 to the nucleus in TNF-alpha-treated cells. We conclude that TNF-alpha induces upregulation of PTEN expression through NF-kappaB activation in human leukemic cells.

The anti-thrombotic activity of surfactins

Platelet aggregation was inhibited and the density of platelet-rich plasma (PRP) clots was decreased by the preincubation of PRP with surfactins, an acidic lipopeptide of Bacillus subtilis complex BC1212 isolated from soybean paste, in dose-dependent manner. Our findings suggest that surfactins are able to prevent a platelet aggregation leading to an inhibition of additional fibrin clot formation, and to enhance fibrinolysis with facilitated diffusion of fibrinolytic agents.

Determination of Roxithromycin by Liquid Chromatography/Mass Spectrometry after Multiple-Dose Oral Administration in Broilers

A highly sensitive and specific method for the determination of roxithromycin in broiler tissues by LC/MS was developed and validated. A dichloromethane extract of the sample was separated on C18 reversed-phase column with acetonitrile-50 mM ammonium acetate (80:20, v/v) as the mobile phase and analyzed by LC/MS via atmospheric pressure ionization/electrospray ionization interface. The limit of detection and limit of quantitation were 1 ng/g and 5 ng/g. The method has been successfully applied to determine for roxithromycin in various tissues of broilers. Residue concentrations were associated with administered dose. At the termination of treatment, roxithromycin was found in all collected samples for both dose groups. Liver was detected to have the highest residual concentration of roxithromycin. Residue concentrations of roxithromycin were lower than its LOQ in all tissues from both dose groups 10 days after the treatment of roxithromycin mixed with drinking water at a dose rate of 15 mg/L or 60 mg/L to each broiler for 7 days.

Simultaneous Determination of Various Macrolides by Liquid Chromatography/Mass Spectrometry

Macrolides are frequently used in veterinary medicine as therapeutic and preventive agents for various diseases. It is difficult to determine macrolides simultaneously with conventional methods due to their similar structures. A simultaneous analysis for erythromycin, roxithromycin, tiamulin and tylosin with LC/MS has been developed. Separation was performed on C18 reversed phase column. Mobile phase was gradiently flowed with 10 mM ammonium acetate and methanol. The mass spectrometer was run in the positive mode and selective ion monitoring mode. The molecular ions were [M+H]+ form at m/z 837.5 for erythromycin, at m/z 859.5 for roxithromycin, at m/z 494.2 for tiamulin and at m/z 916.7 for tylosin. Limits of detection were in the range from 0.001 to 0.01 microgram/g lower than their MRLs.

The Evaluation of Left and Right Ventricular Function by Radionuclide Ventriculography and Echocardiography in Dilated Cardiomyopathy

It has been known that dilated cardiomyopathy(DCM) is characterized by systolic dysfunction of left ventricle(LV), but there were few studies about correlation between LV systolic function, diameter and diastolic function measured by echocardiography and radionuclide ventriculography(RVG) The purpose of this study is to evaluate LV systolic and diastolic function as well as RV function using regional ejection fraction and functional images by RVG in 17 patients with DCM and to compare these variables with echocardiographic data. The results are as follows : 1) DCM showed diffuse systolic and diastolic dysfunction of LV. The systolic impairment is accounted for the diastolic impairment in DCM. 2) The increased standard deviation of phase angle of left ventricle(LVSDph) revealed LV asynchronous contraction in DCM. 3) LVSDph showed significant correlations with other RVG parameters such as LV ejection fraction, and peak ejection rate, peak filling rate and also with LV systolic and diastolic diameter measured by echocardiography. It is concluded that LVSDph may be useful in evaluation of LV systolic and diastolic function in patients with DCM as well as LV asynchronous contraction.