The association of prealbumin, transferrin, and albumin with immunosenescence among elderly males.

OBJECTIVE: As people get older, the innate and acquired immunity of the elderly are affected, resulting in immunosenescence. Prealbumin (PAB), transferrin (TRF), and albumin (ALB) are commonly used markers to monitor protein energy malnutrition (PEM). However, their relationship with the immune system has not been fully explored. METHODS: In our study, a total of 93 subjects (≥65 years) were recruited from Tongji Hospital between January 2015 and February 2017. According to the serum levels of these proteins (PAB, TRF, and ALB), we divided the patients into the high serum protein group and the low serum protein group. Then, we compared the percent expression of lymphocyte subsets between two groups. RESULTS: All the low serum protein groups (PAB, TRF, and ALB) had significant decreases in the percentage of CD4+ cells, CD3+CD28+ cells, CD4+CD28+ cells and significant increases in the percentage of CD8+ cells, CD8+CD28- cells. PAB, TRF, and ALB levels revealed positive correlations with CD4/CD8 ratio, proportions of CD4+ cells, CD3+CD28+ cells, CD4+CD28+ cells, and negative correlation with proportions of CD8+ cells, CD8+CD28- cells. CONCLUSIONS: This study suggested PAB, TRF, and ALB could be used as immunosenescence indicators. PEM might accelerate the process of immunosenescence in elderly males.

Development and validation of an interpretable machine learning model-Predicting mild cognitive impairment in a high-risk stroke population.

Background: Mild cognitive impairment (MCI) is considered a preclinical stage of Alzheimer's disease (AD). People with MCI have a higher risk of developing dementia than healthy people. As one of the risk factors for MCI, stroke has been actively treated and intervened. Therefore, selecting the high-risk population of stroke as the research object and discovering the risk factors of MCI as early as possible can prevent the occurrence of MCI more effectively. Methods: The Boruta algorithm was used to screen variables, and eight machine learning models were established and evaluated. The best performing models were used to assess variable importance and build an online risk calculator. Shapley additive explanation is used to explain the model. Results: A total of 199 patients were included in the study, 99 of whom were male. Transient ischemic attack (TIA), homocysteine, education, hematocrit (HCT), diabetes, hemoglobin, red blood cells (RBC), hypertension, prothrombin time (PT) were selected by Boruta algorithm. Logistic regression (AUC = 0.8595) was the best model for predicting MCI in high-risk groups of stroke, followed by elastic network (ENET) (AUC = 0.8312), multilayer perceptron (MLP) (AUC = 0.7908), extreme gradient boosting (XGBoost) (AUC = 0.7691), and support vector machine (SVM) (AUC = 0.7527), random forest (RF) (AUC = 0.7451), K-nearest neighbors (KNN) (AUC = 0.7380), decision tree (DT) (AUC = 0.6972). The importance of variables suggests that TIA, diabetes, education, and hypertension are the top four variables of importance. Conclusion: Transient ischemic attack (TIA), diabetes, education, and hypertension are the most important risk factors for MCI in high-risk groups of stroke, and early intervention should be performed to reduce the occurrence of MCI.

Clinical efficacy of selenium supplementation in patients with Hashimoto thyroiditis: A systematic review and meta-analysis.

BACKGROUND: Evidence suggests that selenium supplementation could be useful in the treatment of Hashimoto thyroiditis (HT), but the available trials are heterogeneous. This study investigates clinically relevant effects of selenium supplementation in patients with HT. METHODS: A systematic search was performed in PubMed, Web of Science, EMBASE, Scopus, and the Cochrane Library. The latest update was performed on December 3, 2022. We investigated the changes in thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb) after selenium supplementation. The effect sizes were expressed as weighted mean difference (WMD) with 95% confidence intervals (CIs). RESULTS: After screening and full-text assessment, 7 controlled trials comprising 342 patients were included in the systematic review. The results showed that there was no significant change in TPOAb levels (WMD = -124.28 [95% CI: -631.08 to 382.52], P = .631, I2 = 94.5%) after 3 months of treatment. But there was a significant decrease in TPOAb levels (WMD = -284.00 [95% CI: -553.41 to -14.60], P < .05, I2 = 93.9%) and TgAb levels (WMD = -159.86 [95% CI: -293.48 to -26.24], P < .05, I2 = 85.3%) after 6 months of treatment. CONCLUSIONS: Selenium supplementation reduces serum TPOAb and TgAb levels after 6 months of treatment in patients with HT, but future studies are warranted to evaluate health-related quality or disease progression.

Age-related changes in peripheral T-cell subpopulations in elderly individuals: An observational study.

The age-related decline in T-cell function among elderly individuals remains unclear. We thus investigated the interrelationship between T-cell subsets and age to identify the changes in T-cell phenotypes and develop an age prediction model for the elderly population. A total of 127 individuals aged >60 years were divided into three groups (youngest-old group, 61-70 years, n = 34; middle-old group, 71-80 years, n = 53; and oldest-old group, ≥ 81 years, n = 40). The percentage of CD8+CD28- cells (P = 0.001) was highest in the oldest-old group and then followed by the middle-old group, while the youngest-old group was the lowest. Both females and males demonstrated significant decreases in the absolute counts of CD4+CD45RA+ cells (P = 0.020; P = 0.002) and CD8+CD28+ cells (P = 0.015; P = 0.005) with age. Multivariate linear regression showed that the percentage of CD8+CD28- cells (P < 0.001) was an independent predictor of aging after adjusting for sex, body mass index, hospitalization duration, smoking, drinking, chronic medical illness, and medications at admission. In conclusion, our results suggest that aging in elderly individuals is accompanied by a decrease in the counts of T-cell subpopulations. CD8+CD28- cells may be potential targets for elderly individuals in antiaging-related immunosenescence.

Alternating Early Afterdepolarizations Underlying Bradycardia-Dependent Macroscopic T Wave and Discordant Mechanical Alternans.

BACKGROUND: Macroscopic T wave alternans (macro-TWA) often heralds the onset of Torsades de Pointes in patients with QT prolongation. However, the mechanisms underlying macro-TWA remain unclear. We examined the cellular and ionic basis for macro-TWA in rabbits with left ventricular hypertrophy (LVH). METHODS: The renovascular hypertension model was used to induce LVH in rabbits. Action potentials were simultaneously recorded from epicardium and endocardium together with a transmural ECG and isometric contractility in arterially perfused left ventricular wedges. Late sodium current (INa-L) was recorded in single-isolated left ventricular myocytes with the whole cell patch-clamp technique. RESULTS: Macro-TWA and accompanied mechanical alternans occurred spontaneously in 8 of 33 LVH rabbits (P<0.05, versus 0/15 in controls) and were induced by an INa-L enhancer ATX-II at 1 to 3 nM in additional 7. Macro-TWA and mechanical alternans occurred discordantly, that is, that longer QT interval and larger T wave were associated with weaker isometric contvractility. Alternating early afterdepolarizations in the endocardium caused macro-TWA in 12 of 15 LVH rabbits and, therefore, early afterdepolarization-dependent R-from-T extrasystoles and Torsades de Pointes always originated from the beats with longer QT and larger T wave during macro-TWA. INa-L density was significantly larger in LVH myocytes than that of control myocytes. Macro-TWA, mechanical alternans, R-from-T extrasystoles, and Torsades de Pointes were all abolished by INa-L blocker ranolazine or mexiletine. CONCLUSIONS: LVH enhances INa-L density and promotes alternating early afterdepolarizations in the left ventricular endocardium that manifest as macro-TWA with discordant mechanical alternans. INa-L blockade abolishes macro-TWA, mechanical alternans, early afterdepolarization-dependent R-from-T extrasystoles, and Torsades de Pointes.

Is elevated triglyceride/high-density lipoprotein cholesterol ratio associated with poor prognosis of coronary heart disease? A meta-analysis of prospective studies.

BACKGROUND: Elevated triglycerides (TG) and reduced high-density lipoprotein cholesterol (HDL-C) are recognized as essential and independent hazard factors for total death and major adverse cardiovascular events (MACE) in patients with coronary heart disease (CHD). However, whether the increased TG/HDL-C forecasted the prognosis of CHD is still unknown. Therefore, we performed a meta-analysis to investigate the relationship between the elevated TG/HDL-C ratio and poor prognosis of CHD. METHODS: A systematic literature search was conducted in PubMed, Web of Science, EMBASE, and The Cochrane Library, until August 30, 2021. Prospective observational studies regarding the association between TG/HDL-C and long-term mortality/MACEs in CHD patients were included. RESULTS: In total, 6 independent prospective studies of 10,222 participants with CHD were enrolled in the systematic and meta-analysis. Our outcomes of the meta-analysis indicated that the elevated TG/HDL-C group had a significantly increased risk of long-term all-cause mortality (hazard ratio [HR] = 2.92, 95% confidence interval [CI]: 1.75-4.86, P < .05) and long-term MACEs (HR = 1.56, 95%CI 1.11-2.18, P < .05). CONCLUSION: In patients with CHD, the present study showed that the high TG/HDL-C was associated with increased risk of long-term all-cause mortality and MACE.

Monocyte to high-density lipoprotein ratio predict long-term clinical outcomes in patients with coronary heart disease: A meta-analysis of 9 studies.

BACKGROUND: A novel inflammation-related biomarker, the monocyte to high-density lipoprotein cholesterol ratio (MHR), had a great relation to the development and prognosis of coronary atherosclerotic heart disease. Current study was to investigate whether the MHR was a potential tool in predicting the mortality and major adverse cardiac events (MACEs) in patients suffering coronary heart disease (CHD) by meta-analysis. METHODS: The Cochrane Library, PubMed, MEDLINE, Scopus, EMBASE, and Web of science were searched for relevant cohort studies published prior to February 10, 2022. The association between MHR and mortality/MACEs was analyzed in patients with CHD. Hazard ratios (HR) with 95% confidence interval (CI) were calculated to estimate the strength of association. RESULTS: In the meta-analysis, a total of 9 studies of 11,345 patients with CHD were included. Compared with the low level of MHR group, the high MHR value was associated with higher long-term MACEs (HR = 1.72 95% CI 1.36-2.18, P < .001), long-term mortality (HR = 1.71, 95% CI 1.10-2.66, P = .017), and in-hospital mortality/MACEs (HR = 2.82, 95% CI = 1.07-7.41, P = .036). CONCLUSIONS: This study suggested that increased MHR value might be associated with higher long-term mortality and long-term MACEs in CHD patients. MHR might serve as a potential prognostic indicator for risk stratification in patients with CHD.

The effect of glucocorticoids on mortality in severe COVID-19 patients: Evidence from 13 studies involving 6612 cases.

BACKGROUND: Since the start of the coronavirus disease 2019 (COVID-19) pandemic, there is an urgent need for effective therapies for patients with COVID-19. In this study, we aimed to assess the therapeutic efficacy of glucocorticoids in severe COVID-19. METHODS: A systematic literature search was performed across PubMed, Web of Science, EMBASE, and the Cochrane Library (up to June 26, 2021). The literature investigated the outcomes of interest were mortality and invasive mechanical ventilation. RESULTS: The search identified 13 studies with 6612 confirmed severe COVID-19 patients. Our meta-analysis found that using glucocorticoids could significantly decrease COVID-19 mortality (hazard ratio (HR) 0.60, 95% confidence interval (CI) 0.45-0.79, P < .001), relative to non-use of glucocorticoids. Meanwhile, using glucocorticoids also could significantly decrease the risk of progression to invasive mechanical ventilation for severe COVID-19 patients (HR = 0.69, 95% CI 0.58-0.83, P < .001). Compared with using dexamethasone (HR = 0.68, 95% CI 0.50-0.92, P = .012), methylprednisolone use had a better therapeutic effect for reducing the mortality of patients (HR = 0.35, 95% CI 0.19-0.64, P = .001). CONCLUSION: The result of this meta-analysis showed that using glucocorticoids could reduce mortality and risk of progression to invasive mechanical ventilation in severe COVID-19 patients.

Worldwide prevalence of early repolarization pattern in general population and physically active individuals: A meta-analysis.

BACKGROUND: The early repolarization pattern (ERP) has recently been associated with cardiac events such as ventricular arrhythmias and sudden cardiac death. However, estimates of the prevalence of ERP vary widely, especially between the general population and physically active individuals. We performed this systematic review and meta-analysis to quantitatively evaluate the worldwide prevalence of ERP in the general population and physically active individuals. METHODS: We thoroughly searched the PubMed, EMBASE, Web of science, the Cochrane Library, and Scopus databases for relevant studies published until December 20, 2020. Studies in which prevalence was presented or could be estimated from eligible data were included. The pooled prevalence was analyzed using a random-effect model. RESULTS: Finally, we included 29 studies (182,135 subjects) in the general population and 14 studies (8087 subjects) in the physically active individuals. The worldwide pooled prevalence of ERP in the general population was 11.6% (95% confidence interval [CI]: 10.0%-13.3%). The incidence of ERP was 17.0% and 6.2% in men and women, respectively. The prevalence was 20.9% in blacks, 13.4% in Asians, and 10.1% in Caucasians. Additionally, the prevalence of ERP in physically active individuals was 33.9% (95% CI: 25.3%-42.6%). CONCLUSION: A significant difference in the worldwide prevalence of ERP is revealed in this study. The ERP is highly prevalent in men, blacks, and physically active individuals.

Prognostic Utility of the Combination of Platelet Count with Neutrophil-to-Lymphocyte Ratio in Aged Patients with Acute Myocardial Infarction Undergoing Percutaneous Coronary Intervention.

METHOD: This was a study recording 637 patients who were diagnosed with acute myocardial infarction. Our patients were grouped according to the combination of platelet count and neutrophil-to-lymphocyte ratio. The prognostic role of the combination of platelet count and neutrophil-to-lymphocyte ratio on mortality was assessed by the univariate and multivariate Cox regression analysis. RESULT: Our study population was divided into three parts according to the median values of platelet count and neutrophil-to-lymphocyte ratio. It was indicated that platelet count and neutrophil-to-lymphocyte ratio were correlative mutually to a certain degree (p=0.010). The Kaplan-Meier analysis showed that the combination of high platelet count and high neutrophil-to-lymphocyte ratio had a greater risk of death in short- and long-term endpoints (log-rank p=0.046, p < 0.001, respectively). Moreover, by multivariate analysis, both high platelet count and high neutrophil-to-lymphocyte ratio groups were an independent predictor (hazard ratio: 2.132, 95% confidence interval: 1.020-4.454, p=0.044) and long-term mortality (hazard ratio: 2.791, 95% confidence interval: 1.406-5.538, p=0.003). CONCLUSION: The combination of platelet count and neutrophil-to-lymphocyte ratio could be a useful predictor for the prediction of in-hospital and long-term mortality in aged patients with acute myocardial infarction.

The relationship between Chlamydia pneumoniae infection and CD4/CD8 ratio, lymphocyte subsets in middle-aged and elderly individuals.

Chlamydia pneumoniae (C. pneumoniae) is a common respiratory pathogen associated with many inflammatory diseases. There are few data concerning the lymphocyte subsets in middle-aged and elderly individuals with C. pneumoniae infection. A total of 191 patients were included in this study. The study population was categorized into the middle-aged group (40-64 years old) and the elderly group (65-89 years old). Lymphocyte subsets in peripheral blood were examined with multi-colored flow cytometry. Immunological monitoring included lymphocyte subsets, C. pneumoniae IgG and IgM serology. In the middle-aged group, 69.83% individuals presented IgG positivity, which was associated with the inverted CD4/CD8 ratio. Individuals with C. pneumoniae IgG positivity also presented an increased percentage of CD8+CD28- cells and a decreased CD4/CD8 ratio when compared to weakly-positive individuals. In the elderly group, C. pneumoniae IgG positivity was associated with a significant increase in the percentage of CD3+CD56+CD45+ (NKT) cells. In conclusion, altered lymphocyte homeostasis was shown in middle-aged individuals with C. pneumoniae IgG positivity. The senescent phenotypes of T cells might be associated with C. pneumoniae infection in middle-aged individuals.

The predictive value of lymphocyte-to-monocyte ratio in the prognosis of acute coronary syndrome patients: a systematic review and meta-analysis.

BACKGROUND: The association between the lymphocyte-to-monocyte ratio (LMR) and prognosis in the patients with acute coronary syndrome (ACS) is not fully understood. We performed this systematic review and meta-analysis to evaluate the correlation between LMR and mortality or major adverse cardiac events (MACE) in patients with ACS. METHODS: A systematic search was performed in PubMed, MEDLINE, EMBASE, the Cochrane Library, Scopus, and Web of science. The association between LMR and mortality/MACE was analyzed in patients with ACS. The search was updated to April 15, 2020. RESULTS: A total of 5 studies comprising 4343 patients were included in this meta-analysis. The results showed that lower LMR predicted higher short-term mortality/MACE (hazard ratio [HR] = 3.44, 95% confidence interval [CI]: 1.46-8.14, P <  0.05) and long-term mortality/MACE (HR = 1.70, 95% CI: 1.36-2.13, P <  0.05). In the subgroup analysis, there was still statistical significance of long-term mortality/MACE in all subgroups. CONCLUSIONS: This study suggested that lower LMR value might be associated with higher short-term and long-term mortality/MACE in ACS patients. Especially for younger ACS patients, low LMR was more closely associated with poor prognosis.

Neutrophil to high-density lipoprotein ratio has a superior prognostic value in elderly patients with acute myocardial infarction: a comparison study.

BACKGROUND: The importance of the lipid-related biomarkers has been implicated in the pathological process and prognosis of acute myocardial infarction (AMI). Our work was conducted to discuss and compare the predictive ability of the neutrophil to high-density lipoprotein cholesterol (HDL-C) ratio (NHR) with other existing prognostic indices, for instance, the monocyte to HDL-C ratio (MHR) and the low-density lipoprotein cholesterol (LDL-C) to HDL-C ratio (LDL-C/HDL-C) in elderly patients with AMI. METHODS: Our population was 528 consecutive elderly AMI patients (65-85 years) who were enrolled from Tongji Hospital and grouped according to the cutoff points which were depicted by the receiver operating characteristic (ROC). The Kaplan-Meier curves were plotted with the survival data from the follow-up to investigate the difference between cutoff point-determined groups. Moreover, we assessed the impact of NHR, MHR, LDL-C/HDL-C on the long-term mortality and recurrent myocardial infarction (RMI) with Cox proportional hazard models. RESULTS: Mean duration of follow-up was 673.85 ± 14.32 days (median 679.50 days). According to ROC curve analysis, NHR ≥ 5.74, MHR ≥ 0.67, LDL-C/HDL-C ≥ 3.57 were regarded as high-risk groups. Kaplan-Meier analysis resulted that the high-NHR, high-MHR and high-LDL-C/HDL-C groups presented higher mortality and RMI rate than the corresponding low-risk groups in predicting the long-term clinical outcomes (log-rank test: all P < 0.050). In multivariate analysis, compared with MHR and LDL-C/HDL-C, only NHR was still recognized as a latent predictor for long-term mortality (harzard ratio [HR]: 1.96, 95% confidence interval [CI]: 1.02 to 3.75, P = 0.044) and long-term RMI (HR: 2.23, 95% CI: 1.04 to 4.79, P = 0.040). Furthermore, the positive correlation between NHR and Gensini score (r = 0.15, P < 0.001) indicated that NHR was relevant to the severity of coronary artery to some extent. CONCLUSIONS: NHR, a novel laboratory marker, might be a predictor of the long-term clinical outcomes of elderly patients with AMI, which was superior to MHR and LDL-C/HDL-C.

Could platelet-to-lymphocyte ratio be a predictor for contrast-induced nephropathy in patients with acute coronary syndrome?: A systematic review and meta-analysis.

BACKGROUND: Contrast-induced nephropathy (CIN) is acute renal failure observed after administration of iodinated contrast media during angiographic or other medical procedures. In recent years, many studies have focused on biomarkers that recognize CIN and/or predict its development in advance. One of the many biomarkers studied is the platelet-to-lymphocyte ratio (PLR). We performed a systematic review and meta-analysis to evaluate the correlation between PLR level and CIN. METHODS: Relevant studies were searched in PUBMED, EMBASE, and Web of Science until September 15, 2018. Case-control studies reporting admission PLR levels in CIN and non-CIN group in patients with acute coronary syndrome (ACS) were included. The pooled weighted mean difference (WMD) and 95% confidence intervals (95%CI) were calculated to assess the association between PLR level and CIN using a random-effect model. RESULTS: Six relevant studies involving a total of 10452 ACS patients (9720 non-CIN controls and 732 CIN patients) met our inclusion criteria. A meta-analysis of 6 case-control studies showed that PLR levels were significantly higher in CIN group than those in non-CIN group (WMD = 33.343, 95%CI = 18.863 to 47.823, P < .001, I = 88.0%). CONCLUSION: For patients with ACS after contrast administration, our meta-analysis shows that on-admission PLR levels in CIN group are significantly higher than those of non-CIN group. However, large and matched cohort studies are needed to validate these findings and assess whether there is a real connection or just an association.

Comparison of two malnutrition risk screening tools with nutritional biochemical parameters, BMI and length of stay in Chinese geriatric inpatients: a multicenter, cross-sectional study.

OBJECTIVES: The aims of this study were to assess malnutrition risk in Chinese geriatric inpatients using Nutritional Risk Screening 2002 (NRS2002) and Mini-Nutritional Assessment (MNA), and to identify the most appropriate nutritional screening tool for these patients. DESIGN: Cross-sectional study. SETTING: Eight medical centres in Hubei Province, China. PARTICIPANTS: A total of 425 inpatients aged ≥70 years were consecutively recruited between December 2014 and May 2016. PRIMARY AND SECONDARY OUTCOME MEASURES: Nutritional risk was assessed using NRS2002, MNA, anthropometric measurements and biochemical parameters within 24 hours of admission. Comorbidities and length of hospitalisation were recorded. Nutritional parameters, body mass index (BMI) and length of hospital stay (LOS) were employed to compare MNA and NRS2002. Kappa analysis was used to evaluate the consistency of the two tools. RESULTS: The average age was 81.2±5.9 years (range, 70-98). The prevalence of undernutrition classified by NRS2002 and MNA was 40.9% and 58.6%, respectively. Patients undergoing malnutrition had lower BMI, haemoglobin, albumin and prealbumin (p<0.05), and longer LOS (p<0.05). The NRS2002 showed moderate agreement (κ=0.521, p<0.001) with MNA. Both tools presented significant correlation with age, BMI and laboratory parameters (p<0.001). In addition, a significant association between both tools and LOS was found (p<0.05). In addition, the NRS2002 was not different from MNA in predicting nutritional risk in terms of the area under the receiver operating characteristic curve (p>0.05). CONCLUSIONS: The results show a relatively high prevalence of malnutrition risk in our sample cohort. We found that NRS2002 and MNA were both suitable in screening malnutrition risk among Chinese geriatric inpatients.

Association between fetuin-A and prognosis of CAD: A systematic review and meta-analysis.

BACKGROUND: Fetuin-A is an anti-inflammation and anti-calcification factor involved in the course of coronary artery disease (CAD). But the association between serum fetuin-A level and the prognosis of CAD patients was still controversial. To clarify the association between serum fetuin-A level and the prognosis of CAD patients, we conducted the present meta-analysis. METHODS: The included studies should be potentially relevant prospective studies published in English language before January 2019. The target population of the present meta-analysis was restricted to patients with CAD. The results of studies must report hazard ratio (HR) or Kaplan-Meier survival curve for all-cause mortality or incidence of secondary cardiovascular disease (CVD) events. The pooled HRs were analysed by the method of meta-analysis. RESULTS: A total of four prospective studies, including 4256 participants with CAD disease, were chosen to be included. The pooled HR for all-cause mortality was 0.57 (95% CI: 0.37-0.87), showing a statistically significant association between high serum fetuin-A level and low all-cause mortality in CAD patients. For the incidence of secondary CVD events, the pooled HR was 0.86 (95% CI: 0.60-1.23), indicating no statistically significant association between serum fetuin-A level and incidence of secondary CVD events in CAD patients. CONCLUSION: High serum fetuin-A level associated with lower all-cause mortality in patients with CAD. No association between serum fetuin-A level and incidence of secondary CVD events was found in patients with CAD.

Use of humour in medical education: a survey of students and teachers at a medical school in China.

OBJECTIVE: Humour is a powerful resource in medical education. The purpose of this study is to investigate what students and teachers think about the use of humour. What challenges do teachers face in using humour and how they address them are also the subject of the present study. DESIGN: Separate cross-sectional questionnaire surveys. SETTING: Tongji Medical College and Tongji Hospital in China. PARTICIPANTS: 327 students at Tongji Medical College and 165 physician teachers at Tongji Hospital in China. MAIN OUTCOME MEASURES: The primary study outcome was assessed by proportion. RESULTS: 87% of student and teacher respondents agreed with using humour in the didactic setting. They felt humour fostered a positive didactic atmosphere. Interesting clinical case was the most frequently used humour type by teachers and considered the most effective by students. Lack of humorous materials related to the lecture subject was the main challenge to humour use cited by teachers. Collecting humorous materials in teacher's daily work and life, observing teachers with a reputation for successfully using humour, and efficiently using the internet-enhanced humour use ability. CONCLUSION: The present study confirms that most medical students and physician teachers support the use of humour in medical didactics, with particular strategies aiding its use and positive impact.

Verapamil suppresses cardiac alternans and ventricular arrhythmias in acute myocardial ischemia via ryanodine receptor inhibition.

T-wave alternans (TWA) is a potent arrhythmia substrate under the conditions of acute myocardial ischemia. Abnormal intracellular calcium cycling contributes to the genesis of cardiac alternans. Ryanodine receptor (RyR) is a pivotal Ca2+ cycling protein central to Ca2+ signaling in the heart. Here, we investigated the potential role of RyR in cardiac alternans and ventricular arrhythmias in acute myocardial ischemia. Transmembrane action potentials were simultaneously recorded from epicardium and endocardium together with a transmural ECG and isometric contraction force in the arterially perfused left ventricular wedge preparations. Calcium alternans were induced by incremental frequency of field stimulation in rat ventricular myocytes. TWA, mechanical alternans and ventricular arrhythmias were reproducibly induced by rapid pacing in the acute ischemic wedge preparations. Compared with control group, calcium alternans ratio and spontaneous calcium release were increased in acute ischemic myocytes. Verapamil, a phenylalkylamine calcium channel blocker, can successfully abolish spontaneous calcium release, TWA, and ventricular arrhythmias. The inhibition effect of verapamil could be diminished by low concentration of ryanodine (10 nmol/L). However, nifedipine, a dihydropyridine calcium channel blocker, could not block TWA or arrhythmias. Moreover, verapamil, but not nifedipine, significantly decreased ROS production in ischemic myocytes. Collectively, our results indicate that verapamil can significantly inhibit the development of cardiac alternans and ventricular arrhythmias in acute myocardial ischemia, and the mechanism was related to the inhibition of RyR and the protective function to oxidative stress.