ABSTRACT
Objective To investigate the protective effect of high-density lipoprotein (HDL) on the mice cardiac myocytes induced by oxygen and glucose deprivation (OGD).Methods Cardiac cells of primary scavenger receptor-B1 knockout mice (SR-B1-/-) and normal C57 mice (SR-B1+/+) were obtained by protease digestion and differential adhesion method. ① The two kinds of cells were divided into normal control group (Con group), OGD group, OGD+HDL group. Propidium iodide (PI) staining were used to determine the necrosis of cardiac myocytes. ② SR-B1+/+cardiac cells were divided into Con group, OGD group, OGD+HDL group, and phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) inhibitor LY294002 group. PI staining were used to determine the necrosis of cardiac myocytes. TUNEL staining was used to determine the cell apoptosis. The kit was used to determine the contents of MB isoenzyme of creatine kinase (CK-MB) and lactate dehydrogenase (LDH) in the culture medium supernatant. The expressions of SR-B1 and Akt protein were determined by Western Blot.Results ① In SR-B1+/+ cardiomyocytes, HDL could inhibit cell necrosis induced by OGD. There was no protective effect of HDL on OGD in the SR-B1-/- cardiomyocytes.② The study of SR-B1+/+ cells was showed that compared with Con group, necrotic cells were significantly increased and cell activity were significantly decreased, the cell viability were significantly decreased, the contents of LDH and CK-MB in supernatant were significantly increased, the expressions of phosphorylated Akt (p-Akt) and SR-B1 were significantly decreased in OGD group. Compared with OGD group, the number of necrotic cells in the OGD+HDL group was significantly decreased [PI positive cells rate: (26.71±5.94)％ vs. (64.24±18.34)％], the cell activity was significantly increased [(63.84±6.95)％ vs. (26.71±5.13)％], the contents of LDH and CK-MB in supernatant were significantly decreased [LDH (U/L): 896.3±161.5 vs. 1568.3±243.5, CK-MB (U/L): 304.3±72.9 vs. 583.6±81.6], the expressions of p-Akt and SR-B1 were significantly increased (p-Akt/t-Akt: 0.84±0.13 vs. 0.18±0.06, SR-B1/β-actin: 1.23±0.19 vs. 0.09±0.02), with statistically significant differences (allP < 0.05). Compared with OGD+HDL group, necrotic cells in LY294002 group were increased, cell activity was decreased, LDH and CK-MB contents in supernatant were increased, p-Akt and SR-B1 expressions were decreased; there was no statistical difference between LY294002 group and OGD group. There was no significant difference in cell apoptosis among the 4 groups.Conclusions HDL has protective effect on the mice myocardial cells. The mechanism may be related with the up regulation of the expression of SR-B1 protein by the activation of PI3K/Akt pathway.
ABSTRACT
Objective To investigate the feasibility of differentiating lymph node metastases of four types of primary tumors (lymphoma, lung adenocarcinoma, lung squamous cell carcinoma and cholangiocarcinoma) using gemstone spectral imaging (GSI) . Methods Three cases with lymphoma (28 lymph node), five cases with lung adenocarcinoma(30 lymph node), four cases with lung squamous cell carcinoma(24 lymph node) and two cases with cholangiocarcinoma( 10 lymph node) were evaluated by germstona spectra imaging CT scans. Imaging protocol included unenhanced conventional CT scan (120 kVp) ,enhanced GSI (80/140 kVp) on arterial phase and conventional CT scan (120 kVp) on portal phase. CT attenuation values of lymph nodes in the monochromatic images at 11 sets of keV levels (40-140 keV, 10 keV step) and the iodine and water contents of these lymph nodes were measured. All results were analyzed with ANOVA and t test. Results The optimal monochromatic level was 70 keV for the optimal contrast-noise ratio (CNR) of metastatic lymphadenopathy. The CT attenuation values of metastatic lymphadenopathy were (81.36 ±9. 81 ), (58.33 ± 21.55 ), (56. 47 ± 10.62) and (73. 57 ±4. 43 ) HU,respectively, at 70 keV( F = 17.29, P ＜0. 01 ). There were significant differences in CT attenuation values between lymphoma and lung adenocarcinoma, between lymphoma and lung squamous cell carcinoma and between lung squamous cell carcinoma and cholangiocarcinoma (P ＜ 0. 05 ). The differences in CT attenuation values were significant between cholangiocarcinoma and lung squamous cell carcinoma, between cholangiocarcinoma and lymphoma ( P ＜ 0. 05 ). There was no difference in CT attenuation values at all 11 sets of keV levels between lung squamous cell carcinoma and lung adenocarcinoma ( P ＞ 0. 05 ). The iodine contents of lymphoma, lung adenocarcinoma, lung squamous cell carcinoma and cholangiocarcinoma were ( 1. 93 ± 0. 04 ), ( 1.16 ± 0. 15 ), ( 1.25 ± 0. 21 ) and ( 1.44 ± 0. 04 ) g/L, respectively. The water contents of lymphoma, lung adenocarcinoma, lung squamous cell carcinoma and cholangiocarcinoma were (1029.40 ± 20. 85), (1024.98 ± 11.19), (1022.12 ± 12. 94) and (1030.87 ± 10.10) g/L,respectively. Except between lung squamous cell carcinoma and lung adenocarcinoma, the differences in the iodine contents of metastatic lymphadenopathy were significant among tumors ( P ＜ 0. 05 ). There was no difference in the water contents of metastatic lymphadenopathy among tumors ( P ＞ 0. 05 ). Conclusions Although CT spectral imaging fails to differentiate metastatic lymphadenopathy of lung adenocarcinoma and lung squamous cell carcinoma, it is also a promising method of distinguishing metastatic lymphadenopathy of malignant tumors by CT attenuation values in monochromatic images and iodine contents in material density images. The optimal monochromatic level was determined to be at 70 keV for providing the optimal CNR of metastatic lymphadenopathy.