ObjectiveTo observe and analyze the short-term effects of intravitreal injection of Conbercept (IVC) on the expression levels of matrix metalloproteinase (MMP)-2 and MMP inhibitor-2 (TIMP-2) in the aqueous humor of eyes with proliferative diabetic retinopathy (PDR). MethodsA prospective clinical study. From March 2024 to June 2024, 30 consecutive patients with 30 eyes with PDR (PDR group) undergoing IVC combined with pars plana vitrectomy (PPV) at Department of Ophthalmology of The First Affiliated Hospital of University of Science and Technology were included in the study, along with 20 patients with 20 eyes undergoing cataract surgery (control group) during the same period. In the PDR group, IVC treatment was performed 3 to 7 days before PPV, and 0.05-0.10 ml aqueous humor was collected before IVC and before PPV. In the control group, 0.05-0.10 ml aqueous humor was collected before cataract surgery. The levels of vascular endothelial growth factor (VEGF), MMP-2, and TIMP-2 in the aqueous humor were measured using enzyme-linked immunosorbent assay. For normally distributed data, independent samples t-test were used for comparison between two groups; for non-normally distributed data, the Mann-Whitney U test was used. Correlation analysis was performed using Pearson's correlation coefficient. ResultsThere were no statistically significant differences in age (Z=－1.810) and gender composition (χ2=3.450) between the PDR group and the control group (P＞0.05). Before IVC, VEGF and MMP-2 expression levels were (0.23±0.10), (2.11±1.32) ng/ml and (0.12±0.03), (0.53±0.26) ng/ml in patients' aqueous fluid in PDR group and control group, respectively. The expression level of TIMP-2 and the ratio of MMP-2/TIMP-2 were (0.99±0.26), (1.76±0.11) ng/ml and 2.04 (1.19, 2.98), 0.36 (0.15, 0.39), respectively. Compared with the control group, the expression levels of VEGF and MMP-2 in aqueous humor in PDR group (t=－5.030, －5.260) and the ratio of MMP-2/TIMP-2 (Z=－5.740) were significantly increased, with statistical significance (P＜0.01). The expression level of TIMP-2 was significantly lower than that of control group, the difference was statistically significant (t=12.120, P＜0.01). After IVC, the expression levels of VEGF and MMP-2 in aqueous humor of PDR patients were (0.13±0.03) and (2.11±1.32) ng/ml, respectively. The expression level of TIMP-2 and the ratio of MMP-2/ TIMP-2 were (0.95±0.28) ng/ml and 1.57 (1.02, 3.13), respectively. Compared with before IVC, the expression level of VEGF in aqueous humor in PDR group after IVC was significantly decreased, and the difference was statistically significant (t=6.080, P＜0.01). The expression levels of MMP-2 (t=1.220), TIMP-2 (t=0.290) and the ratio of MMP-2/TIMP-2 (Z=－0.260) were not significantly different (P=0.270, 0.780, 0.800). After IVC, there was no significant difference in VEGF expression level between PDR group and control group (t=－1.200, P=0.240). The expression level of MMP-2 was still significantly increased (t=－5.880), the expression level of TIMP-2 was still significantly decreased (t=11.520), and the ratio of MMP-2/TIMP-2 was still significantly increased (Z=－5.780), with statistical significance (P＜0.01). Correlation analysis showed that VEGF was positively correlated with MMP-2 in aqueous humor of PDR patients before IVC (r=0.590, P＜0.01). ConclusionsIVC can effectively reduce the level of VEGF in the aqueous humor of eyes with PDR in the short term, but it has no significant effect on the levels of MMP-2 and TIMP-2.
Objective To compare the graft patency rates of conventional on-pump coronary artery bypass grafting （CCABG） and off-pump coronary artery bypass grafting （OPCAB） at 2 weeks，3 months and 1 year after surgery. Methods Clinical data of 200 patients who underwent coronary artery bypass grafting （CABG） in the First Affiliated Hospital of Harbin Medical University from May 2010 to November 2011 were retrospectively analyzed. All the 200 patients were divided into two groups according to different surgical procedures they received：CCABG group，61 patients including 32 male patients and 29 female patients with their age of 59.8±4.7 years；and OPCAB group，139 patients including 72 male patients and 67 female patients with their age of 59.6±8.9 years. Graft patency of all the patients was evaluated by 256-slice multislice computed tomography angiography （256-MSCTA） at 2 weeks，3 months and 1 year after CABG and compared between two groups. Results At 2 weeks，3 months and 1 year after CABG，the graft patency rates of left internal mammary artery （LIMA） grafting were not statistically different between CCABG group and OPCAB group，as well as those of great saphenous vein （GSV） grafting （P＞0.05）. The 1 year graft patency rates of LIMA grafting of CCABG group and OPCAB group were 92.31% and 91.94% respectively，and 1 year graft patency rates of GSV grafting of CCABG group and OPCAB group were 91.35% and 90.00% respectively. To compare the graft patency rates of different distal anastomotic locations，grafting to the left anterior descending （LAD） coronary artery had significantly higher patency rate than grafting to the right coronary artery （RCA，P＜0.05）. The 1 year graft patency rates of LAD grafting and RCA grafting were 97.78% and 85.90% respectively. But there was no statistical difference in graft patency rates at different respective distal anastomotic locations between OPCAB group and CCABG group （P＞0.05）. To compare early clinical outcomes of two groups，postoperative mechanical ventilation time，length of ICU stay，24-hour mediastinal drainage，24-hour blood transfusion，length of hospital stay，and hospitalization cost of OPCAB group were significantly shorter or lower than those of CCABG group （P＜0.05）. Conclusion Short-term graft patency rates of CCABG and OPCAB are quite similar. Patency rate of grafting to LAD is higher than that of grafting to RCA. OPCAB can produce better perioperative clinical outcomes than CCABG.