Relationship between left ventricular mechanical synchrony and left ventricular systolic function: a CZT-SPECT analysis.

BACKGROUND: CZT-SPECT has good agreement in the evaluation of mechanical synchronization compared with conventional SPECT. The aim of this study was to evaluate the correlation between left ventricular mechanical contraction synchrony and left ventricular systolic function by gated myocardial perfusion imaging (GMPI) using cadmium-zine-telluride (CZT) single photon emission computed tomography (SPECT). METHODS: This retrospective study involved 371 patients (239 males and 132 females, mean age 61.06 ± 11.78 years old) who underwent GMPI at the Nuclear Medicine Department of Shanxi Cardiovascular Hospital from January 2020 to August 2020. Systolic synchrony parameters and left ventricular systolic function parameters were calculated via Emory Cardiac Toolbox, including PP, PSD, PHB, HS, HK, EDV, ESV, and LVEF. Based on LVEF value, patients were divided into the severe reduction group (group 1, 127 cases, EF < 35%), moderate reduction group (group 2, 47 cases, 35% ≤ EF < 45%), mild reduction group (group 3, 50 cases, 45% ≤ EF < 50%) and normal group (group 4, 147 cases, EF ≥ 50%). Differences in PP, PSD, PHB, HS and HK among the four groups were compared using one-way ANOVA. Differences between two groups were compared using LSD-t test. The correlation among functional and mechanical contraction synchrony factors were analyzed using Pearson test. RESULTS: PP, PSD, PHB, HS and HK were significantly different among the four groups (F = 5.20, 188.72, 202.88, 171.05, 101.36, P < 0.001). Pairwise comparison tests showed significant differences in PSD and PHB in each two groups, and HS and HK in each two groups except for group 2 and 3 (t = 0.28 and 0.39, both P > 0.001). PP was significantly higher in group 1, relative to group 3 (t = 2.43, P < 0.001) and group 4 (t = 3.67, P < 0.001). Pearson correlation analysis revealed that LVEF negatively correlates with PP, PSD, PHB (r = 0.194, - 0.790, - 0.799, all P < 0.001). HS and HK showed positive correlation for LVEF (r = 0.778 and 0.795, P < 0.001), PSD, PHB and ESV were had good positive correlation (r = 0.778, 0.795, P < 0.001), PSD, PHB and EDV had good positive correlation (r = 0.722, 0.732, P < 0.001). However, PP had poor correlation with EDV (r = 0.095, P > 0.001). HS and HK were negatively correlated with EDV and ESV (r = - 0.700 to - 0.594, P < 0.001). CONCLUSION: CZT SPECT GMPI provided left ventricular mechanical contraction synchrony parameters that correlated well with left ventricular systolic function. Worse left ventricular mechanical contraction synchrony lead to decreased LVEF, making the systolic synchrony parameters valuable in the prediction of left ventricular systolic function.

MiR-451 suppresses proliferation, migration and promotes apoptosis of the human osteosarcoma by targeting macrophage migration inhibitory factor.

Previous studies have shown that MiR-451 plays an important role in human osteosarcoma carcinogenesis, but the underlying mechanism by which MiR-451 affects the osteosarcoma has not been fully understood. This study intends to uncover the mechanism by which MiR-451 functions as a tumor suppressor. The expression of MiR-451 in osteosarcoma tissues and osteosarcoma cell lines was monitored by real-time PCR. The proliferation ability was examined by MTT and cell cycle assay. The migration and apoptosis of cells were monitored by migration assay and flow cytometry, respectively. Moreover, the angiogenesis of HUVEC cells transfected with MiR-451 mimics was examined by tube formation assay. The effect of MiR-451 on MIF was determined by luciferase assays and Western blot assay. The results showed that MiR-451 expression level was significantly reduced in the osteosarcoma compared with normal bone tissues. Overexpression of MiR-451 significantly attenuated the proliferation and migration, and induced the apoptosis of osteosarcoma cells. Furthermore, the angiogenesis of HUVEC cells transfected with MiR-451 mimics was assayed and the decreased angiogenic ability was detected compared to the controls. Finally, we demonstrated that MiR-451 overexpression inhibited the malignant behavior of osteosarcoma by downregulating MIF. These findings suggest that MiR-451 may act as a tumor suppressor in osteosarcoma. MiR-451 inhibited cell proliferation, migration and angiogenesis and promoted apoptosis of human osteosarcoma cells, at least partially, by inhibiting the expression of MIF. MiR-451/MIF may be a novel therapeutic target in treatment of osteosarcoma.