Kinetics studies on effects of extraction techniques on bioactive compounds from Vernonia cinerea leaf.

Recently, unconventional methods especially microwave-assisted hydrodistillation extraction (MAHE) is being used as an alternative technique for extracting bioactive compounds from plant materials due to its advantages over conventional methods such as Soxhlet extraction (SE). In this study, bioactive compounds were extracted from Vernonia cinerea leaf using both MAHE and SE methods. In addition, the kinetic study of MAHE and SE methods were carried out using first- and second-order kinetic models. The results obtained showed that MAHE can extract higher yield of bioactive compounds from V. cinerea leaf in a shorter time and reduced used of extracting solvent compared with SE method. Based on the results obtained, second-order kinetic models can actually describe the extraction of bioactive compounds from V. cinerea leaf through MAHE with extraction rate coefficient of 0.1172 L/gmin and extraction capacity of 1.0547 L/g as compared to SE with 0.0157 L/gmin and 1.1626 L/g of extraction rate coefficient and extraction capacity, respectively. The gas chromatography-mass spectrometry analysis of the oil showed the presence of numerous heavy fractions in the oil obtained through MAHE as compared with the SE method. Moreover, the electric consumption and environmental impacts analysis of the oil suggested that MAHE can be a suitable green technique for extracting bioactive compounds from V. cinerea leaf.

Myocardial perfusion imaging in humans by contrast echocardiography using polygelin colloid solution.

This study evaluated the myocardial contrast effect and safety of polygelin colloid solution selectively injected into the coronary arteries in 25 patients during two-dimensional echocardiography. Six patients (group I) had selective intracoronary injections of nonagitated and 19 (group II) of hand-agitated polygelin colloid solution. Myocardial contrast was seen on two-dimensional echocardiographic cross sections in three patients of group I and in all patients of group II; in 16 patients it was also seen on M-mode echocardiograms. The contrast effect lasted for 15 to 60 seconds. The intensity of myocardial opacification was not significantly influenced by the amount of polygelin colloid solution injected, heart rate or cardiac size. The total number of contrast-enhanced segments after right and left coronary artery injections delineated the entire cross-sectional area in any given view. None of the patients developed symptoms during or immediately after the injections. One patient had transient second degree atrioventricular block after a right coronary wedge injection, one patient showed a QRS axis shift and two others had transient T wave changes. There were no aortic blood pressure changes and no significant serum enzyme (creatine kinase [CK], CK-MB fraction, glutamic oxaloacetic transaminase) elevation or alterations of left ventricular function assessed echocardiographically. It is concluded that hand-agitated polygelin colloid solution is a useful and safe intracoronary contrast agent for delineating myocardial perfusion areas on two-dimensional echocardiography in humans.

Assessment of right heart hemodynamics by contrast echocardiography.

We studied inferior vena cava contrast echocardiography after upper extremity injection in 70 subjects; 59 were patients and 11 were controls. Inferior vena cava contrast was seen in 35 patients and in 1 control. "A-wave synchronous pattern" of contrast appearance was observed in 13 patients and 1 normal subject. The pattern did not depend upon the height of right atrial a-wave pressure or the right ventricular (RV) end-diastolic pressure, but was related to the respiratory cycle. A "random pattern" of contrast appearance was seen in 3 patients with cardiac arrhythmia and normal right heart hemodynamics. One patient with ventricular premature beats showed both "a-wave synchronous" and "random" patterns. A "v-wave synchronous pattern" was found in 20 patients, of which 17 had tricuspid regurgitation. Persistence of inferior vena cava contrast correlated with the height of right atrial v-wave (r = 0.87, p less than 0.001) and the severity of tricuspid regurgitation estimated from RV cineangiography. The differences of RV systolic pressure and echocardiographic right ventricular dimension between the study patients with and without tricuspid regurgitation did not reach statistical significance. We conclude: the echocardiographic RV dimension and the degree of RV hypertension are not predictors for the presence of tricuspid regurgitation and its severity; inferior vena cava contrast echocardiography may be used to estimate the severity of tricuspid regurgitation.

Visualization and analysis of right heart blood flow patterns by contrast echocardiography.

UNLABELLED: The clinical utility of visualization of blood flow patterns across the tricuspid valve (TV) and pulmonary valve (PV) by M-mode contrast echocardiography was studied in 38 patients with documented valvular or congenital heart disease and in 15 controls. Diastolic turbulence was observed in the TV outflow side in three patients with tricuspid stenosis. Turbulent flow was also detected during systole in patients with septal defects (atrial septal defect in four patients and ventricular septal defect in one patient) in the right ventricular outflow tract and in three atrial septal defect patients also in the inflow tract, presumably because of increased volume of flow. Tricuspid regurgitation (11 patients) was characterized by retrograde laminar jet throughout systole, while in pulmonary regurgitation (six patients) retrograde flow was initially laminar although later on it might become turbulent. In pulmonary hypertension (29 patients) antegrade flow occurred approximately to mid-systole and then was interrupted by retrograde laminar flow which contributed to the mid-systolic closure of the pulmonary valve and pulmonary regurgitation in some cases. CONCLUSIONS: contrast echocardiography is a useful technique to analyse right heart blood flow patterns and may aid the diagnosis of various right heart abnormalities.