Impact of the COVID-19 Pandemic on the Professional Attitudes of Medical Students: A Pre-Post-Like Study.

OBJECTIVE: This study assesses the difference in professional attitudes among medical students, both before and after coronavirus disease 2019 (COVID-19), and identifies the determinants closely associated with it, while providing precise and scientific evidence for implementing precision education on such professional attitudes. METHODS: A pre-post-like study was conducted among medical students in 31 provinces in mainland China, from March 23, to April 19, 2021. RESULTS: The proportion of medical students whose professional attitudes were disturbed after the COVID-19 pandemic, was significantly lower than before the COVID-19 pandemic (χ2 = 15.6216; P < 0.0001). Compared with the "undisturbed -undisturbed" group, the "undisturbed-disturbed" group showed that there was a 1.664-fold risk of professional attitudes disturbed as grade increased, 3.269-fold risk when others suggested they choose a medical career rather than their own desire, and 7.557-fold risk for students with COVID-19 in their family, relatives, or friends; while the "disturbed-undisturbed" group showed that students with internship experience for professional attitudes strengthened was 2.933-fold than those without internship experience. CONCLUSIONS: The professional attitudes of medical students have been strengthened during the COVID-19 pandemic. The results provide evidence of the importance of education on professional attitudes among medical students during public health emergencies.

Evaluation of myocardial injury induced by different ablation approaches (radiofrequency ablation versus cryoablation) in atrial flutter patients: a meta-analysis.

Background: To evaluate myocardial injury in Atrial flutter (AFL) patients undergoing Radiofrequency ablation (RF) and cryoablation (CRYO) treatments.Methods: We conducted a systematic search on PubMed, Embase, Cochrane Library, and CBM databases. All relevant clinical trials (up to October 2018) on myocardial injury in AFL patients were retrieved and subsequent results analyzed with a random-effects model or a fixed-effects model.Results: A total of eight clinical trials with a sample size of 644 patients, were identified and incorporated in the present study. The results indicated no significant differences in creatine kinase (CK) levels (mean difference (MD) = 62.74, P=0.46; 4-6 h and MD = 30.73, P=0.49; 12-24 h after ablation), creatine kinase MB(CK-MB) levels (MD = 17.32, P=0.25; 12-24 h post-ablation), troponinI (TnI) levels (MD = 0.12, P=0.08; 6 h after ablation), and troponin T (TnT) levels (MD = 0.30, P=0.08; 4-6 h post-ablation) between the two treatment approaches. However, patients receiving CRYO xhibited higher levels of CK (MD = 179.54, P=0.04; tested immediately after the procedure), CK-MB (MD = 10.08, P=0.004) 4-6 h after ablation, and TnT (MD = 0.19, P=0.002) tested the next morning. Moreover, those patients had a significantly reduced pain perception (odds ratio (OR) = 0.05, P=0.04) compared with those in the RF group.Conclusion: These results indicate that CRYO in comparison with RF significantly increases myocardial injury in AFL patients. Additionally, it decreases pain perception during the procedure. Further large-sampled studies are needed to support these findings.

Telmisartan protects against microvascular dysfunction during myocardial ischemia/reperfusion injury by activation of peroxisome proliferator-activated receptor γ.

BACKGROUND: We investigated the potential of telmisartan to improve microvascular dysfunction induced by myocardial ischemia/reperfusion (I/R) injury by activating the peroxisome proliferator-activated receptor gamma (PPARG) pathway. METHODS: Forty-eight male rabbits were randomly allocated into sham-operated, I/R, GW9662, telmisartan, telmisartan-GW9662, or candesartan groups. Rabbits were anesthetized, and the left anterior descending coronary artery (LAD) was ligated for 60 minutes. Following reperfusion for 6 hours, angiotensin II content of the heart was determined using radioimmunoassay. Myocardial neutrophil accumulation and microvessel cross-sectional area were examined histologically. Myocardial capillaries were examined with transmission electron microscopy. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the myocardium were measured using enzyme-linked immunosorbent assay. Western blot was utilized for investigating the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and PPARG. RESULTS: Angiotensin II concentration was significantly increased in all treatment groups compared with the sham-operated group (P < 0.05, all). Accumulation of polymorphonuclear neutrophils was significantly lower, while microvessel cross-sectional area was significantly higher in the telmisartan, telmisartan-GW9662, and candesartan groups compared with the I/R group (P < 0.05). ICAM-1 and VCAM-1 levels were also significantly lower, and correlated with lower NF-κB expression in these groups. The effects were the most significant in the telmisartan group compared with the telmisartan-GW9662 and candesartan groups. Telmisartan significantly increased PPARG protein expression compared with all other groups (P < 0.05, all). CONCLUSIONS: Except for the typical effects of angiotensin II-receptor blocker, telmisartan improved microvascular dysfunction during myocardial I/R injury via the PPARG pathway.

[Effect of probucol and losartan on growth factors after balloon angioplasty in rabbits].

OBJECTIVE: To investigate the effect of probucol and losartan on the prevention of restenosis after balloon angioplasty in hypercholesterolaemic rabbits, and to examine the expression of growth factors. METHODS: Forty male New Zealand white rabbits were randomly divided into high cholesterol diet group, probucol group, losartan group and combined drugs group. After one week of diet, all rabbits were injured on iliac arteries with balloon. Four weeks after the injury, the morphology of the iliac arteries of the rabbits were observed, and the insulin-like growth factor-I receptor (IGF-IR) and vascular endothelial growth factor (VEGF) were examined by immunohistochemical methods. RESULTS: Compared with the high cholesterol diet group, the lumen areas of the probucol group, losartan group and combined drugs group were larger (P < 0.01), the intimal areas were smaller (P < 0.05), and the expression of IGF-IR and VEGF significantly decreased (P < 0.05). There was no statistically significant difference among the three groups. CONCLUSION: Probucol and losartan can prevent the restenosis of rabbits' iliac artery from balloon injury, and inhibit the expression of IGF-IR and VEGF. There is no statistical difference between combined drugs and single drug administration.

[Cox regression analysis on influencing factors of coronary heart disease among people over 40 years of age].

OBJECTIVE: To explore the affecting factors on coronary heart disease among people over 40 years of age in Guangxi area, China. METHODS: Baseline data was gathered through the Third National Blood Pressure Survey in 1991 in China. A total number of 11 818 adults over 40 years old had been studied in Guangxi province. Data of morbidity and mortality of coronary heart disease was obtained. RESULTS: Cardiovascular events were related to systolic blood pressure, diastolic blood pressure, pulse pressure, smoking, BMI regardless of their myocardial infarct (MI) history. Cox regression analysis showed that the relative risk for cardiovascular events increased by 21 [95% confidence interval (CI): 9.06-48.44] times for those people having MI history. When pulse pressure, systolic blood pressure, diastolic blood pressure increased by every 10 mm Hg, the relative risk for cardiovascular events increased by 1.29 (95% CI: 1.11-1.49), 1.18 (95% CI: 1.02-1.22), 1.13 (95% CI: 1.05-1.28) respectively. There was 1.23 (95% Cl: 1.05-1.45) times higher in smoker than non-smoker on relative risk for cardiovascular events. When BMI increasing 1, the relative risk for cardiovascular events would increase 1.03 (95% CI: 1.01-1 .05) times. CONCLUSION: Hypertension, smoking, increase of BMI were the risk factors of coronary heart disease among people who were over 40 years of age.

[Effect of lycopene on DNA oxidative damage of cells in rats].

OBJECTIVE: Observe the protective effect of Lycopene(LP) on DNA damage. METHODS: Rats were given LP after 4 weeks, the DNA break in peripheral blood lymphocytes and liver cells from the rats were analyzed with single cell gel electrophoresis. RESULTS: Compared with control, the damage of DNA in LP group were reduced significantly(P < 0.05). CONCLUSION: LP could protect DNA damage of peripheral blood lymphocytes and liver cells in rats.

[The effect and mechanism of felodipine on monocrotaline induced pulmonary hypertension in rats].

OBJECTIVE: To explore the effect and the mechanism of felodipine on pulmonary hypertension. METHODS: Adult male Wistar rats were given a single dose of subcutaneous monocrotaline (MCT, 60 mg/kg) to induce the mold of pulmonary hypertension. Felodipine (5 mg/kg) was administered intraperitoneally every day for 4 weeks after MCT injection. The parameters of right ventricular systolic pressure were monitored. The levels of endothelin-like immunoreactivity (ir-ET) and calcitonin gene related peptide (CGRP) in the plasma and the heart and pulmonary tissues were measured by radioimmunoassay and colorimetric analysis. Right ventricular myocardial tissue was studied under electron microscope. RESULTS: Continuous injection of felodipine significantly inhibited the progression of pulmonary artery pressure [(44.6 +/- 4.4) mm Hg versus (30.3 +/- 2.1) mm Hg, (18.7 +/- 2.2) mm Hg]. Histological examination revealed that felodipine effectively prevented pulmonary arterial medial thickening. Felodipine significantly increased the level of CGRP in plasma [(84 +/- 19) pg/ml versus 149 +/- 21) pg/ml], pulmonary homogenate [(22 +/- 4) pg/ml versus (29 +/- 3) pg/ml] and myocardial homogenate [(20.9 +/- 1.6) pg/ml versus 27.5 +/- 2.9) pg/ml]. There was no change in the level of ir-ET in the heart and pulmonary tissues. Myocardial damage in the right ventricle was less severe in the felodipine treated group. CONCLUSIONS: Long-term use of felodipine was effective in preventing pulmonary hypertension induced by MCT. The underlying mechanism may be partly related to the increase of CGRP as well as the inhibition of Ca(2+) inflow. The results indicate that felodipine may be considered for clinical trials in the treatment of primary pulmonary hypertension.