[Microvascular perfusion and cardiac function after revascularization assessed by myocardial contrast echocardiography in patients with acute ST-segment elevation myocardial infarction].

Objectives: To evaluate microvascular perfusion and left ventricular function in patients with acute ST-segment elevation myocardial infarction after revascularization using myocardial contrast echocardiography (MCE), and to explore clinical influencing factors of abnormal microvascular perfusion in these patients. Methods: This is a cross-sectional study. The analysis was performed among patients admitted to Peking University People's Hospital for acute ST-segment elevation myocardial infarction (STEMI) from June 2018 to July 2021. All patients underwent percutaneous coronary intervention (PCI) and completed MCE within 48 hours after PCI. Patients were divided into normal myocardial perfusion group and abnormal perfusion group according to the myocardial perfusion score. The echocardiographic indexes within 48 hours after PCI, including peak mitral valve flow velocity (E), mean value of early diastolic velocity of left ventricular septum and lateral mitral annulus (Em), left ventricular global longitudinal strain (GLS) and so on, were analyzed and compared between the two groups. Multivariate logistic regression analysis was used to evaluate the influencing factors of myocardial perfusion abnormalities. Results: A total of 123 STEMI patients, aged 59±13 years with 93 (75.6%) males, were enrolled. There were 50 cases in the normal myocardial perfusion group, and 73 cases in the abnormal myocardial perfusion group. The incidence of abnormal myocardial perfusion was 59.3% (73/123). The left ventricular volume index ((62.3±18.4)ml/m2 vs. (55.1±15.2)ml/m2, P=0.018), wall motion score index (WMSI) (1.59 (1.44, 2.00) vs. 1.24(1.00, 1.47), P<0.001) and mitral E/Em (17.8(12.0, 24.3) vs. 12.2(9.2, 15.7), P<0.001) were significantly higher whereas left ventricular global longitudinal strain (GLS) ((-10.8±3.4)% vs. (-13.8±3.5)%, P<0.001) was significantly lower in the abnormal myocardial perfusion group than those in the normal myocardial perfusion group. Multivariate logistic regression analysis showed that left anterior descending (LAD) as culprit vessel (OR=3.733, 95%CI 1.282-10.873, P=0.016), intraoperative no/low-reflow (OR=6.125, 95%CI 1.299-28.872, P=0.022), and peak troponin I (TnI) (OR=1.018, 95%CI 1.008-1.029, P=0.001) were independent risk factors of abnormal myocardial perfusion. As for ultrasonic indexes, deceleration time of mitral E wave (OR=0.979, 95%CI 0.965-0.993, P=0.003), mitral E/Em (OR=1.100, 95%CI 1.014-1.194, P=0.022) and WMSI (OR=7.470, 95%CI 2.630-21.222, P<0.001) were independently related to abnormal myocardial perfusion. Conclusions: The incidence of abnormal myocardial perfusion after PCI is high in patients with acute STEMI. Abnormal myocardial perfusion is related to worse left ventricular systolic and diastolic function. LAD as culprit vessel, intraoperative no/low-reflow and peak TnI are independent risk factors of abnormal myocardial perfusion.

Genome-wide identification and analysis of the SGR gene family in Cucumis melo L.

Chlorophyll (CHL) is present in many plant organs, and its metabolism is strongly regulated throughout plant development. Understanding the fate of CHL in senescent leaves or during fruit ripening is a complex process. The stay-green (SGR) protein has been shown to affect CHL degradation. In this study, we used the conserved sequences of STAY-GREEN domain protein (NP_567673) in Arabidopsis thaliana as a probe to search SGR family genes in the genome-wide melon protein database. Four candidate SGR family genes were identified in melon (Cucumis melo L. Hetao). The phylogenetic evolution, gene structure, and conserved motifs were subsequently analyzed. In order to verify the function of CmSGR genes in CHL degradation, CmSGR1 and CmSGR2 were transiently overexpressed and silenced using different plasmids in melon. Overexpression of CmSGR1 or CmSGR2 induced leaf yellowing or fruit ripening, while silencing of CmSGR1 or CmSGR2 via RNA interference delayed CHL breakdown during fruit ripening or leaf senescence compared with the wild type. Next, the expression profile was analyzed, and we found that CmSGR genes were expressed ubiquitously. Moreover, CmSGR1 and CmSGR2 were upregulated, and promoted fruit ripening. CmSGR3 and CmSGR4 were more highly expressed in leaves, cotyledon, and stem compared with CmSGR1 or CmSGR2. Thus, we conclude that CmSGR genes are crucial for fruit ripening and leaf senescence. CmSGR protein structure and function were further clarified to provide a theoretical foundation and valuable information for improved performance of melon.

[Clinical study on hemodynamics, blood gases and hemorheologic monitoring of patients with cor pulmonale].

14 patients of cor pulmonale in convalescent stage were studied with Swan-ganze catheter technique. The pulmonary arterial pressure, cardiac output, arterial blood gases, transcutaneous gases tension and hemorrheologic measurement were monitored simultaneously at definite intervals within 24 hours. The results showed that the mean value of the pulmonary arterial pressure (MPAP), arterial carbon dioxide tension (PaCO2), transcutaneous carbon dioxide tension (tcPCO2), hematocrit(H), whole blood viscosity (eta b) and plasma viscosity (eta p) were higher at night than those at daytime. While the value of cardiac output (CO), arterial oxygen tension (PaO2) and transcutaneous oxygen tension (tcPO2) showed a converse result, most of them showed more predominant at daytime and tended to be lowered at night. The MPAP in some of convalescent patients might decrease to normal, but in the pulmonary hypertension group [MPAP greater than or equal to 2.66 Kpa (20 mmHg)] the day and night measurements of MPAP, CO, PaO2, PaCO2, tcPO2, tcPCO2 were fluctuate more obviously than in normal group (P less than 0.01). The day and night hemorrheologic measurements such as H, eta b, eta p etc. showed that the blood viscosity increased more significantly at night than at daytime. The cardiac output (CO, CI) seemed to be a little bit lower in some patients especially in those with high pulmonary arterial pressure and at night. These results suggest that the variation of the day and night measurements of hemodynamics, blood gas, hemorrheologic changes have some rule.(ABSTRACT TRUNCATED AT 250 WORDS)

[Ventricular arrhythmias in patients with cor pulmonale].

This paper reported the results of 24 hours continuous ECG, day time and overnight arterial blood gas/pH and serum electrolytes in 20 patients with cor pulmonale, in order to investigate the rule of changes of ventricular arrhythmias (VA). The results were as follows: (1) Incidence of VA in 24 hours Holter Monitoring was 100%. (2) Frequent VPBs were increased significantly in period of acute attack (40%, P less than 0.05). (3) Non-sustained VT in the nocturnal (40%) was more than the day time in period of attack (P less than 0.05). (4) Relationship between VA and variables in period of attack: PaCO2 (r = 0.90) greater than arterial blood pH (r = -0.87) greater than PaO2 (r = -0.63); in relieved period VA were only related to serum potassium (r = -0.86). The authors speculated the severity of VA in period of attack was related with worse of arterial blood gas/pH, cardiac dysfunction and compensated enhance of sympathetic activity. It seems that the view accorded with theory of Yin-Yang in TCM.