Three-dimensional echocardiography of the thoracic aorta.

OBJECTIVES: The feasibility and diagnostic potential of three-dimensional echocardiography, using transoesophageal multiplane echocardiography for the assessment of thoracic aortic pathology, has not been evaluated. METHODS: We studied 21 patients (10 women, 11 men), mean age 52.1 years (range 20-78). Images for three-dimensional reconstruction were acquired during a diagnostic multiplane transoesophageal echocardiographic examination. In all, 30 acquisitions were performed: 19 of the ascending aorta and 11 of the arch and descending aorta. Three-dimensional reconstruction was performed to visualize normal aortic segments in three patients with a normal thoracic aorta, postoperative anatomy in seven, chronic aortic dissection in two, non-dissecting aneurysm in seven (three patients had coexisting thrombi) and protruding aortic atheroma in two. RESULTS: Three-dimensional image quality was scored excellent in 17 acquisitions (57%), adequate in 10 (33%) and inadequate in three (10%). Anyplane two-dimensional views of regions of interest of the aorta were reconstructed off-line from the data sets, which provided improved analysis with potential for quantitation. Advanced computer-assisted imaging modalities (electronic vivisection, lumen cast display, detail extraction) were feasible. CONCLUSIONS: We conclude that three-dimensional echocardiography of the thoracic aorta is feasible. Adequate image quality is obtained in the vast majority of patients, which adds additional qualitative and quantitative information to routine multiplane transoesophageal echocardiographic studies.

Biochemical evaluation of acetyl salicylic acid in relation to different diets.

Effect of aspirin on some biochemical and nutritional parameters was studied in rats fed with high fat, low fat, high protein or low protein diets. Two doses of aspirin (50 and 150 mg/kg rat body weight) were tested. The experiment continued for 10 days. Results showed that, when rats fed high fat diet, high dose of aspirin significantly decreased body weight gain, food efficiency ratio, plasma high density lipoproteins-cholesterol and its ratio to total cholesterol. Low dose of aspirin significantly reduced plasma total lipids. Low aspirin dose significantly increased plasma glucose level, when low fat diet was fed. Feeding high protein diet during administration of both doses of aspirin significantly reduced plasma total lipids and albumin/globulin ratio, while both doses significantly elevated plasma globulins. Low aspirin dose reduced plasma HDL-ch and significantly elevated plasma total proteins. In rats fed low protein diet, both aspirin doses significantly increased plasma triglycerides. The high dose significantly increased albumin/globulin ratio.

Dobutamine stress echocardiography for assessment of perioperative cardiac risk in patients undergoing major vascular surgery.

BACKGROUND: The purpose of this study was to determine the predictive value of dobutamine stress echocardiography for perioperative cardiac events in patients scheduled for elective major noncardiac vascular surgery. METHODS AND RESULTS: Patients (n = 136; mean age, 68 years) unable to exercise underwent a dobutamine stress test before surgery (incremental dobutamine infusion [10-40 micrograms.kg-1.min-1] continued with atropine [0.25-1 mg i.v.] if necessary to achieve 85% of the age-predicted maximal heart rate without symptoms or signs of ischemia). The clinical risk profile was evaluated by Detsky's modification of Goldman's risk factor analysis. Echocardiographic images were evaluated by two observers blinded to the clinical data of the patients, and results of the test were not used for clinical decision making. Technically adequate images were obtained in 134 of 136 patients, one major complication occurred (ventricular fibrillation), and three tests were discontinued prematurely because of side effects. Finally, data from 131 patients were analyzed with univariate and multivariate methods. The dobutamine stress test was positive (new or worsened wall motion abnormality) in 35 of 131 patients. In the postoperative period, five patients died of myocardial infarction, nine patients had unstable angina, and one patient developed pulmonary edema. All patients with cardiac complications (15 patients) had a positive dobutamine stress test. No cardiac events occurred in patients with negative tests. Five patients with a technically inadequate or prematurely stopped test were operated on without complications. By multivariate analysis (logistic regression), only age > 70 years and new wall motion abnormalities during the dobutamine test were significant predictors of perioperative cardiac events. CONCLUSIONS: Dobutamine stress echocardiography is a feasible, safe, and useful method for identifying patients at high or low risk of perioperative cardiac events. The test yields additional information, beyond that provided by clinical variables, in patients who are scheduled for major noncardiac vascular surgery.

[Bioelectrical characteristics of the membrane of identified Coretus corneus mollusk neurons A and B upon activation and blocking of the electrogenic sodium pump]. / Bioélektricheskie kharakteristiki membrany identifitsirovannykh neironov A i B molliuska Coretus corneus pri aktivatsii i blokirovanii élektrogennogo natrievogo nasosa

Activation of the electrogenic sodium pump by means of increasing concentration of intracellular sodium ions in identified neurons A and B of the mollusc was followed by the hyperpolarization, decrease of the excitability, and depression of the neurons rhythmic activity. Apart from that, the amplitude and the maximal rates of rise of ascending (VB) and descending (VH) phases of action potential (AP) were almost unchanged. The depression of the electrogenic sodium pump activity due to 2,4-DNP and potassium-free medium, led to the depolarization, increase of excitability and frequency of the rhythmic activity, and decrease of AP, VB, and VH. The decrease and increase of the excitability may be explained by the changes of the critical level of depolarization. The decrease of AP, VB and VH may be accounted for by the changes of time parameters of activation and inactivation of sodium and potassium channels which are characteristic for the depolarization effect.