[The Effect and Mechanism of Hyperoside on High Glucose-induced Oxidative Stress Injury of Myocardial Cells].

OBJECTIVE: To explore the effect and mechanism of hyperoside on high glucose-induced oxidative stress injury of myocardial cells. METHODS: Oxidative stress injury of myocardial cells was simulated by treating with high glucose. Cells were divided into five groups: control group (5.5 mmol/L glucose); high glucose model group (35 mmol/L glucose); hyperoside protection groups (35 mmol/L glucose +4, 8, 20 nmol/L hyperoside). Cells were incubated for 48 h. The cell viability was detected by CCK-8. Apoptosis was measured through flow cytometry. The level of ROS was tested by Reactive Oxygen Species Assay Kit DCFH-DA with flow cytometer. The level of SOD and MDA was detected by SOD Assay Kit and MDA Assay Kit respectively. The protein levels of phosphatidylinositide 3-kinases (PI3K), protein kinase B (AKT), p-AKT, nuclear factor erythroid 2-related factor 2 (Nrf2) and p-Nrf2 were detected by Western blot. The activation of AKT was analyzed by immunofluorescence staining. RESULTS: Compared with control group, the cell viability, the levels of SOD, the expression of PI3K, the ratio of p-AKT/AKT and p-Nrf2/Nrf2 and the percentage of AKT positive cells in high glucose group were decreased with enhancive apoptosis and levels of ROS and MDA (P<0.05). Compared with high glucose group, the cell viability, the levels of SOD, the expression of PI3K, the ratio of p-AKT/AKT and p-Nrf2/Nrf2 and the percentage of AKT positive cells in hyperoside group (4, 8, 20 nmol/L) were increased with reduced apoptosis and levels of ROS and MDA (P<0.05). CONCLUSION: Hyperoside protects myocardial cells against oxidative stress injury via activation of PI3K/AKT/Nrf2 signal pathway.

Protective effect and mechanism of estrogen receptor ß on myocardial infarction in mice.

The protective effect and the mechanism of estrogen receptor ß (ERß) on myocardial infarction (MI) in mice were explored. A total of 12 female Tg-ERß transgenic mice and 12 non-transgenic littermate control (NLC) wild-type C57 mice were used for the present study. Both transgenic and wild-type mice had similar baseline data such as age, sex, and weight. The mouse model of MI was established by coronary artery ligation method, and the cardiac structure and function changes of the mouse were observed by ultrasonic echocardiography on days 1, 3 and 7 after the operation. RT-PCR method was used to detect the expression of collagen I, α-SMA, TGF-ß mRNA in the mouse heart, and Masson staining was used to detect cardiac fibrosis. At 3 days after operation, echocardiographic posterior wall thickness at end diastole (PWTD) and end systolic PWTS of Tg-ERß mice were significantly reduced, and left ventricular systolic diameter and left ventricular diastolic diameter significantly increased (P<0.05) compared with NLC mice. The levels of expression of Tg-ERß cardiac tissue collagen I, α-SMA, TGF-ß mRNA were significantly lower than those in the NLC mice (P<0.05). In conclusion, Tg-ERß exerts a protective effect on MI.

Metallically coated dielectric rectangle resonator.

The double transfer matrix method (DTMM) is proposed for calculating the eigenvalues of the resonant mode of a metallically coated dielectric rectangle resonator. Two-dimensional electromagnetic analyses are performed to investigate the optical influences induced by planar structure parameters. The results show that there theoretically exists a highest Q-factor resonance for both TE and TM modes at a certain length-width ratio with fixed resonant wavelength and resonator area. Due to the influence of surface plasma polaritons (SPPs) trapped at the corners of the resonator which is not considered in DTMM, the TM mode resonances are deformed and deviate severely from that of the analytical model. The geometric deformation on the resonator is introduced by replacing the four right angles with circular boundaries, and the SPP accompanied mode behaviors are corrected to the standing waves.

Tailoring the plasmonic whispering gallery modes of a metal-coated resonator for potential application as a refractometric sensor.

Plasmonic whispering gallery (WG) modes confined in metal-coated resonators are theoretically investigated by electromagnetic analyses. The resonance can be tuned from internal surface plasmonic WG modes to the hybrid state of the plasmonic mode by an introduced isolation layer. As the coated metal is reduced in size, the optical resonance is shifted out by the mode coupling of the internal and external surface plasmonic WG modes. Based on the optical leak of the plasmonic WG mode, the optical influences led by the surroundings with a variable refractive index are considered. Device performance criteria such as optical power leak, resonant wavelength shift, and threshold gain are studied. Full wave simulations are also employed and the results present good consistency with analytic solutions. The metal-coated resonator assisted by an active material is expected to provide promising performance as a refractometric sensor.