A Lipophilic Fucoxanthin-Rich Phaeodactylum tricornutum Extract Ameliorates Effects of Diet-Induced Obesity in C57BL/6J Mice

Phaeodactylum tricornutum (P. tricornutum) comprise several lipophilic constituents with proposed anti-obesity and anti-diabetic properties. We investigated the effect of an ethanolic P. tricornutum extract (PTE) on energy metabolism in obesity-prone mice fed a high fat diet (HFD). Six- to eight-week-old male C57BL/6J mice were switched to HFD and, at the same time, received orally placebo or PTE (100 mg or 300 mg/kg body weight/day). Body weight, body composition, and food intake were monitored. After 26 days, blood and tissue samples were collected for biochemical, morphological, and gene expression analyses. PTE-supplemented mice accumulated fucoxanthin metabolites in adipose tissues and attained lower body weight gain, body fat content, weight of white adipose tissue (WAT) depots, and inguinal WAT adipocyte size than controls, independent of decreased food intake. PTE supplementation was associated with lower expression of Mest (a marker of fat tissue expandability) in WAT depots, lower gene expression related to lipid uptake and turnover in visceral WAT, increased expression of genes key to fatty acid oxidation and thermogenesis (Cpt1, Ucp1) in subcutaneous WAT, and signs of thermogenic activation including enhanced UCP1 protein in interscapular brown adipose tissue. In conclusion, these data show the potential of PTE to ameliorate HFD-induced obesity in vivo.

Late apical filling by color Doppler M-mode during dipyridamole stress echocardiography: a useful contribution to wall motion analysis

It has been shown that regional myocardial ischemia during angioplasty is associated with retarded apical filling. To test the importance of retarded apical filling by color Doppler M-mode to detect ischemia during dipyridamole stress echocardiography, we evaluated 29 patients (12 women, aged 57 to 87 years). High-dose dipyridamole (0.84 mg/kg for 10 minutes) was used. The color M-mode record was used to calculate the duration of abnormal apical flow as measured from the onset of the QRS complex to the disappearance of color signals directed toward the apex. Echocardiographic images were compared at rest and during stress to identify the presence of new or worsening wall motion abnormalities (WMAs). Fourteen patients (group A) were designated as having coronary artery disease on the basis on WMAs during the stress test and abnormal coronary anatomy. Fifteen patients (group B) without WMAs in the presence of normal coronary anatomy were designated as having no coronary artery disease. All but two patients in group A had an abnormal apical filling response to dipyridamole stress (sensitivity 86%). In these patients the marked retardation of apical filling was detected during ischemia (55 +/- 18 msec versus 120 +/- 34 msec) (p <0.01). In group B there were no dynamics in apical filling (specificity 100%). Color M-mode Doppler imaging showed retarded apical filling during dipyridamole-induced myocardial ischemia. This abnormal filling pattern may be a useful adjunct to WMAs during dipyridamole stress echocardiography.

Pulsed Doppler assessment of left ventricular diastolic function in atrial septal defect

From January 1986 through December 1990, we used pulsed Doppler echocardiography to evaluate left ventricular diastolic function in 43 patients with an ostium secundum atrial septal defect. The study population included 27 females and 16 males, whose ages ranged from 6 to 58 years (mean, 26 years). The patients were grouped according to degree of pulmonary hemodynamic impairment: patients in Group 1 (n = 6) had severe pulmonary hypertension, those in Group 2 (n = 10) had mild-to-moderate pulmonary hypertension, and those in Group 3 (n = 27) had no pulmonary hypertension. For comparison, we also evaluated 30 healthy individuals. All control subjects had a normal left ventricular filling profile. Of the 43 study patients, 8 (19%) showed Doppler echocardiographic signs of impaired left ventricular relaxation, including a prolonged left ventricular isovolumic relaxation time, decreased peak left ventricular diastolic inflow velocity, and a prolonged mean deceleration time of early diastolic flow velocity. Of these 8 patients, 5 were from Group 1, 1 was from Group 2, and 2 were from Group 3. A positive correlation (r = 0.66; standard error of the estimate = 0.32) was found between the late-to-early left ventricular diastolic inflow velocity ratio and the pulmonary-to-systemic vascular resistance ratio. Our results showed impaired left ventricular relaxation in 8 (19%) of patients with atrial septal defect; 5 of these patients had severe pulmonary hypertension. We therefore conclude that left ventricular diastolic dysfunction is closely related to severe pulmonary hypertension.

Use of continuous-wave Doppler echocardiography to evaluate the hemodynamic importance of atrial systole in patients with mitral stenosis

Continuous-wave Doppler echocardiography was used to assess the hemodynamic role of left atrial systole and its effect on left ventricular performance in 31 patients with pure mitral stenosis. Seventeen (group I) had severe stenosis, and 14 (group II) had mild-to-moderate stenosis. The contribution of atrial systole to cardiac output was 15% in group I and 24% in group II (p < 0.01). This study shows the effectiveness of using continuous-wave Doppler echocardiography to assess the influence of atrial systole on left ventricular performance in patients with mitral stenosis.

Doppler echocardiographic analysis of the transmitral flow velocity profile in patients with ventricular septal defects

Using continuous-wave Doppler echocardiography, we evaluated the mitral flow velocity pattern in 30 ventricular septal defect patients, 11 of whom had severe pulmonary vascular obstructive disease (Group I); 10 of whom had severe pulmonary hypertension without pulmonary vascular obstructive disease (Group II); and 9 of whom had no pulmonary hypertension and hemodynamically unimportant left-to-right shunts (Group III). In addition, 25 healthy subjects (Group IV) were studied for comparative purposes. The peak velocity of early left ventricular filling (E) was significantly lower in Group I than in all the other groups (p < 0.01). The peak velocity of late left ventricular filling (A) was significantly higher (p < 0.01) in Group I than in Group III, or than in normal individuals (Group IV) (p < 0.01). The ratio A/E was the most prominent difference between Group I patients and the other groups, with Group I having a significantly higher ratio (p < 0.01), which was 1 or greater in 9 of 11 patients. In contrast, none of the remaining ventricular septal defect patients or normal subjects had an A/E ratio of 1 or greater. Group II had increased mitral flow velocities, while Group III had normal mitral flow velocity profiles. A positive correlation between the magnitude of the left-to-right shunt and early mitral flow velocity peak (r = 0.86) and late peak (r = 0.81) was found, regardless of the degree of pulmonary hypertension. These results indicate that significant alterations of the mitral flow velocity pattern, which mimic the abnormalities associated with impaired left ventricular diastolic function (A/E ratio of 1 or greater), occur in ventricular septal defect patients who have severe pulmonary vascular obstructive disease. The transmitral velocity profiles in the ventricular septal defect patients without severe pulmonary vascular obstructive disease were similar to those of the normal patients, although the values relative to the degree of left-to-right shunting were higher in the ventricular septal defect patients.