Increase of microsomal glucose-6-phosphatase activity after chronic ethanol administration

To study the effect of chronic ethanol administration on the activity of hepatic microsomal glucose-6-phosphatase, female rats were pair-fed liquid diets with 36% of total calories either as ethanol or isocaloric carbohydrate (controls). The remainder of the diet contained 35% of total calories as fat, 18% as protein, and 11% as additional carbohydrate. Six weeks of ethanol feeding as isocaloric substitution for carbohydrate increased significantly the activity of glucose-6-phosphatase (expressed per mg microsomal protein) both in fed (38%; p < 0.001) and fasted 18%; p < 0.02) rats. When expressed per unit of body weight, the enzyme activity was increased even further both in fed (66%; p < 0.01) and fasted (43%; p < 0.01) rats. Another group of rats received diets containing 36% of calories either as ethanol or isocaloric fat. The remainder of the diet contained 11% of total calories as carbohydrate, 18% as protein, and 35% as additional fat. Six weeks of this ethanol feeding as isocaloric substitution for fat again increased glucose-6-phosphatase activity significantly. Ultracentrifugation in a Cs⁺-containing sucrose gradient to separate rough and smooth microsomes revealed that the increase in glucose-6-phosphatase activity after ethanol feeding occurred mainly in the smooth microsomal membranes.     

Treatment and prophylaxis of ventricular arrhythmias in acute myocardial infarction

Remarkable advances have been made in the management of cardiac disease in the last 20 years, but antiarrhythmic drug strategy in the acute phase of myocardial infarction remains less than satisfactory. Primary ventricular fibrillation (VF), once considered predictable on the basis of detection of “warning arrhythmias,” cannot be anticipated. Management must be either expectant or prophylactic. Restriction of drug use to selected patients and the apparent lack of effect of VF on late prognosis argue for the former approach, yet safe and effective prevention of VF is an attractive therapeutic goal. High-dose intravenous lidocaine probably offers efficacy but the risk-benefit ratio of this regimen is still debated. Adoption of a prophylactic regimen mandates drug administration to a large number of patients who either are not at risk of developing VF (noninfarct patients) or who are destined not to develop VF (70 to 95% of infarct patients). Ventricular arrhythmias other than VF are common in acute infarction and, for emotional rather than scientific reasons, often are aggressively treated. Little evidence exists to support this management. Few ventricular arrhythmias at this time in infarction have either immediate importance or prognostic significance. Reevaluation of antiarrhythmic drug use and arrhythmia treatment in acute myocardial infarction is long overdue. However, there is a paucity of controlled data upon which to base new strategies, and clinical research in this field is hampered by ethical considerations, by rigidly held but unscientifically based beliefs and by a lack of fundamental knowledge of arrhythmia mechanisms and their significance.     

Analysis of exercise-induced changes in R wave amplitude in asymptomatic men with electrocardiographic ST-T changes at rest

Fifty asymptomatic men, 44 (88 percent) of whom were pilots or allied aviation personnel, were referred because of resting ST-T electrocardiographic changes indistinguishable from those of myocardial ischemia. Because of the nature of their occupations, cardiac catheterization was performed to establish the presence or absence of coronary artery disease. Exercise tests were performed and analyzed retrospectively with respect to exercise-induced changes in the S-T segment and R wave amplitude. The results were correlated with coronary angiographic and echocardiographic findings.The 50 subjects were classified into two groups: Group I, 5 men with angiographically proved coronary artery disease, and Group II, 45 men without significant coronary arterial obstruction. Analysis of the S-T segment changes at peak exercise showed 21 subjects (42 percent) with a positive exercise test and 29 (58 percent) with a negative test. All subjects in Group I had a positive test. Sixteen subjects (35 percent) in Group II had a false positive result. Analysis of exercise-induced changes in R wave amplitude revealed that six subjects had a positive R wave response on the basis of sum of the changes in voltage in the leads measured (Δ∑R). Four of the six subjects had coronary artery disease and the other two were thought to have a cardiomyopathy. One subject with coronary artery disease had a negative R wave response. Echocardiography revealed five subjects with asymmetric septal hypertrophy; two of these had a positive exercise test and three a negative test on the basis of S-T segment criteria.Thus, symptom-limited treadmill exercise testing of asymptomatic men with resting ST-T electrocardiographic changes produced a high incidence rate of false positive results when S-T segment criteria were used, whereas analysis of changes in R wave amplitude yielded only two false positive results, both in men who had evidence of other heart disease.     

Anterolateral ST segment depression in acute inferior myocardial infarction: angiographic and clinical implications

We examined the relationship between coronary anatomy and anterolateral ST segment depression during inferior acute myocardial infarction (AMI) in 84 consecutive survivors of inferior AMI, who underwent prospective coronary angiography a median time of 2 weeks after AMI. Multivessel disease was defined as two or more significantly (greater than 70%) stenosed vessels. A QRS scoring system was used to estimate myocardial infarct size. Patients with ST depression had more multivessel disease compared to patients with no ST depression (53% vs 6%, p less than 0.01), more left anterior descending stenoses (36% vs 10% p less than 0.05), and higher QRS scores (5.8 +/- 3.2 vs 2.6 +/- 1.8, p less than 0.01) indicating larger infarcts. Patients with ST depression and one-vessel disease (47%) still had higher QRS scores compared to patients with no ST depression (4.8 +/- 2.9 vs 2.6 +/- 1.8, p less than 0.001) and had an increased prevalence of infarct-related vessels with a terminal branch supplying the left ventricular lateral wall or apex. We conclude that anterolateral ST depression during inferior AMI may indicate the presence of additionally stenosed vessels or that the infarct-related vessel has a large vascular territory. The absence of ST depression virtually precludes multivessel disease.     

Postinfectious glomerulonephritis in a renal allograft associated with a mycotic aneurysm of a coronary artery

Postinfectious glomerulonephrltis is well known to occur after various infections but is rare in renal allografts, perhaps as a result of immunosuppressive therapy. This report describes a 47-year-old man who, seven years after receiving a cadaveric renal transplant, had biopsy-proved crescentic glomerulonephritls presenting with gross hematuria and rapidly progressive renal failure. The patient underwent cardiac surgery to define an abnormal structure shown on echocardiography, and a mycotic aneurysm of the left circumflex artery was discovered. Such aneurysms are uncommon and rarely diagnosed during life. This case appears to be the first report of glomerulonephritis associated with a mycotic aneurysm of a coronary artery and one of the few reports of postinfectious glomerulonephritis in a renal allograft.     

罂粟科植物罂粟、延胡索和岩黄连镇痛作用的研究进展

疼痛是人类的第五大生命体征,既是机体的一种自我保护,同时也是机体对伤害性刺激的预警。尽管阿片类药物具有显著的不良反应及成瘾性,但目前该类药物仍是治疗严重急慢性疼痛的主要治疗药物。本文整理了具有镇痛功效的罂粟科植物罂粟、延胡索和岩黄连,从古籍记载、主要活性成分、药理作用和临床研究几个方面对其进行综述,以期更科学地发掘具有镇痛强,成瘾性低,毒副作用小的药物。     

GE Discovery MR750W磁共振故障维修三例

目的通过对GE 3.0T磁共振MR750W的3例故障进行分析、检修并总结,降低设备故障率。方法通过分析我院GE 3.0T磁共振MR750W近年来发生的氦压机停机、RRX与RF Hub连接中断和氦压机流速过低故障产生原因,进行针对性预防性维护。结果通过快速、精准的故障判断,为设备维修节省了时间,保障病人的就诊需求,总结经验促进做好平时维护保养工作。结论磁共振系统庞大、精密、复杂,定期做好预防性维护保养,多注意观察设备运行状态,降低设备的故障率。