Endosonographic features of pseudomyxoma peritonei.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
Y T Lee
Publications and source records attributed to Y T Lee.
Effects of menopause and obesity on lipid profiles in middle-aged Taiwanese women: the Chin-Shan Community Cardiovascular Cohort Study.
In this cross-sectional study, we examined the associations between lipid profiles and menopausal status, age, and obesity in Taiwanese women. The study population, established in 1990-91, consisted of 671 premenopausal and 872 postmenopausal women from the Chin-Shan Community Cardiovascular Cohort (CCCC). The associations of age, body mass index (BMI), and menopausal status with serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), apoproteins (Apo) A-1 and B, and lipoprotein (a) [Lp (a)] were evaluated. The results showed that menopause was associated with significant increases in TC, LDL-C, TG, and Apo B levels (all P < 0.001). Total cholesterol, LDL-C, TG, and Apo B levels increased consistently with BMI in middle-aged women, regardless of menopausal status. Among women aged 45-49, menopausal women had significantly higher levels of TC and LDL-C than premenopausal women (P < 0.01). However, TG and Apo B levels were higher in postmenopausal than in premenopausal women aged 50-54 years (P < 0.05). Standardized regression analyses showed all lipid variables, except those of Apo A1 and Lp (a) before menopause and TC, LDL-C, and Lp (a) after menopause, were significantly associated with BMI (all P < 0.01). We conclude serum lipid levels in Taiwanese women are no more strongly associated with menopause and BMI than with age.
Adult↗
Ultrasonic tissue characterization with integrated backscatter during inotropic stimulation.
Ultrasonic tissue characterization with integrated backscatter is an objective method to quantitatively define the physical state of the myocardium. To determine if backscatter imaging during inotropic stimulation could be used objectively to determine the myocardial viability and ischemia in patients with ischemic heart disease, the backscatter changes were examined in 23 patients with myocardial infarction during dobutamine stress two-dimensional (2-D) echocardiography. Coronary angiography was performed within 1 to 2 days after the stress test. The results of this study demonstrated that changes in backscatter variability correlated significantly with the wall motion changes in stress echocardiography during dobutamine infusion (p < 0.0001). In addition, it was shown that the backscatter changes were significantly different in various types of myocardial tissue. In 23 healthy control segments, the ultrasonic backscatter variability was preserved and unchanged during inotropic stimulation (p = NS). In 15 viable infarct zones, restoration or an increase in backscatter variability during low-dose dobutamine infusion was noted, this being lost when ischemia developing during high-dose dobutamine infusion (p < 0.01). In 9 nonviable infarct zones, the phase-weighted variation was usually < or = 0 and did not change significantly during inotropic stimulation, regardless of the patency of the infarct-related arteries. In 15 remote ischemic myocardial zones, the backscatter variability was preserved at the baseline level, did not change during low-dose dobutamine infusion, but decreased significantly during high-dose dobutamine stress (p < 0.01). In conclusion, dobutamine stress tissue characterization could offer an objective approach for the detection of myocardial viability and ischemia, and might be a useful adjunct to the conventional stress echocardiography.
Cardiotonic Agents↗
Power Doppler-derived speckle tracking image of intraventricular flow in patients with anterior myocardial infarction: correlation with left ventricular thrombosis.
The abnormal spatial distribution of intraventricular flow is superior to clinical and two-dimensional (2-D) echocardiographic variables in predicting left ventricular thrombosis after myocardial infarction. Echocardiography was prospectively performed in 79 patients within 72 h after anterior wall myocardial infarction onset and repeated before discharge. The apical rotating flow pattern in color flow map was recognized as abnormal. By power Doppler echocardiography, the moving blood could generate speckle tracking images to delineate the intraventricular flow. A swirling flow pattern indicating the compartmentalization of left ventricular blood flow with some blood stagnant in the apical dyssynergic area was identified. The flow pattern shown by the speckle tracking image was superior to the color-flow map in correlating with left ventricular thrombosis. It implicated that the more the detail in which we can describe the blood flow pathway, the more information we can realize.
Adult↗
Water-soluble Hexasulfobutyl[60]fullerene inhibit low-density lipoprotein oxidation in aqueous and lipophilic phases.
Oxidative modification of low-density lipoprotein (LDL) plays a pivotal role in the pathogenesis of atherosclerosis. Increasing the resistance of LDL to oxidation may therefore mitigate, or even prevent, atherosclerosis. A new water-soluble C60 derivative, hexasulfobutyl[60]fullerene [C60 - (CH2CH2CH2CH2-SO3Na)6; FC4S], consisting of 6 sulfobutyl moieties covalently bound onto the C60 cage is a potent free radical scavenger. This study explored the antioxidative effect of sulfobutylated fullerene derivatives (FC4S) on LDL oxidation. FC4S was found to be effective in protecting LDL against oxidation induced by either Cu2+ or azo peroxyl radicals generated initially in the aqueous or lipophilic phase, respectively. Levels of the oxidative products, conjugated diene and thiobarbituric acid-reactive substances, and the relative electrophoresis mobility of the LDL were decreased. The addition of 20 microM FC4S at the early stage of oxidation increased the kinetic lag time from 69 +/- 11 to 14 +/- 10 min (P < 0.05) and decreased the propagation rate from 17.1 +/- 2.6 to 6.3 +/- 1.0 mOD/min (P < 0. 005). Persistent suppression of peroxidation reaction was observed upon further addition of FC4S after full consumption of all endogenous antioxidants during the propagation period. Intravenous injection of hypercholesterolemic rabbits with FC4S (1 mg/kg/day) efficiently decreased atheroma formation. Data substantiate the use of FC4S as an excellent hydrophilic antioxidant in protecting atheroma formation, via removing free radicals, in either aqueous or lipophilic phase.
Animals↗
Atrophy and intestinal metaplasia one year after cure of H. pylori infection: a prospective, randomized study.
BACKGROUND & AIMS: Helicobacter pylori-infected gastric mucosa evolves through stages of chronic gastritis, intestinal metaplasia (IM), glandular atrophy (GA), and dysplasia before carcinoma develops. We studied if H. pylori eradication would alter the course of premalignant histologic changes in the stomach. METHODS: Volunteers from the Yantai County in China underwent upper endoscopy with biopsy specimens obtained from the antrum and corpus. H. pylori-infected subjects were randomized to receive either a 1-week course of omeprazole, amoxicillin, and clarithromycin (OAC) or placebo. At 1 year, endoscopies with biopsies were repeated. RESULTS: A total of 587 H. pylori-infected subjects were randomized to OAC (n = 295) and placebo (n = 292). At 1 year, H. pylori was eradicated in 226 subjects assigned to OAC. In the placebo group, 245 patients remained H. pylori infected. Analysis of paired samples obtained from the same patients showed that acute and chronic gastritis decreased in both the antrum and corpus after H. pylori eradication (P<0.001) and activity of IM decreased in antrum (P = 0.014). In the H. pylori-infected group, antral biopsy specimens had more pronounced acute gastritis (P = 0.01), whereas corpus specimens showed increased acute and chronic gastritis (P<0.001) and a marginal increase in GA (P = 0.052). When histologic changes were compared between the 2 groups, decrease in acute and chronic gastritis was more frequent after H. pylori eradication (P<0.001) but changes in IM were similar. In the H. pylori-infected group, increase in GA was seen in the corpus (P = 0.01). CONCLUSIONS: At 1 year, H. pylori eradication is beneficial in preventing progression of pathologic changes of the gastric mucosa.
Adult↗
EUS-guided injection of cyanoacrylate for bleeding gastric varices.
BACKGROUND: Bleeding gastric varices is a highly fatal condition. Recurrent bleeding after hemostasis achieved by endoscopic methods is common, and obliteration of gastric varices is difficult to assess. Our aim was to investigate the use of endosonography (EUS) in monitoring cyanoacrylate injection to obliterate gastric varices. METHODS: Patients who presented with bleeding gastric varices were treated with bolus injection(s) of cyanoacrylate (0.5 mL cyanoacrylate mixed with 0.7 mL Lipiodol) until bleeding was controlled; 47 patients received "on-demand" injection only in response to recurrent bleeding (on-demand group). Another group of 54 patients underwent biweekly EUS followed by repeated injection of cyanoacrylate (repeated-injection group) until all gastric varices were obliterated. The primary outcome was recurrent bleeding-free interval and survival rate. RESULTS: The two groups of patients were comparable demographically. Although the rates of early (</=48 hour) bleeding recurrence were similar with repeated or on-demand injection (7.4% versus 12.8%, p = 0.5), late recurrence of bleeding (>48 hour) was significantly reduced in the repeated-injection group (18.5% versus 44.7%, p = 0.0053, odds ratio 0.28 (95% CI [0.12, 0. 69]). Cumulative probability of recurrent bleeding-free interval was higher in the repeated-injection than the on-demand group (log-rank test, p = 0.0053). There was a numeric trend toward improved survival in the repeated-injection group. CONCLUSION: Gastric varices obliteration with cyanoacrylate under EUS monitoring reduces recurrent bleeding and may improve survival.
Adult↗
Seasonal effects on cardiovascular mortality in older patients.
Explore the source record for details and available documents.
Cardiovascular Diseases↗
Effect of n-3 fatty acids on the composition and binding properties of lipoproteins in hypertriglyceridemic patients.
BACKGROUND: Treatment of hyperlipidemic patients with fish oil results in an increase in plasma LDL cholesterol despite a marked decrease in the LDL precursor, VLDL. OBJECTIVE: We studied the relation between VLDL composition and LDL concentrations. DESIGN: Fourteen hypertriglyceridemic patients were treated with encapsulated fish oil (containing 1.45 g eicosapentaenoic acid and 1. 55 g docosahexaenoic acid/d) for 4 wk. Venous blood samples were collected before and after treatment. Eleven normolipidemic subjects served as a control group. RESULTS: Fish oil effectively lowered plasma lipid and apolipoprotein (apo) E concentrations in the hypertriglyceridemic patients, whereas apo B concentrations increased. The lipid and apolipoprotein content of VLDL decreased, whereas LDL cholesterol and LDL apo B increased. Fractionation of VLDL by heparin-affinity chromatography showed that before treatment hypertriglyceridemic patients had more VLDL in the 0.05-mol NaCl/L subfraction and less in the 0.20-mol/L subfraction than did control subjects (P < 0.05), whereas the subfraction distribution pattern was normalized after fish-oil treatment. Nevertheless, plasma concentrations of the 0.05-mol NaCl/L subfraction were decreased and those of the 0.20-mol/L subfraction were increased in hypertriglyceridemic patients after fish-oil treatment (P < 0.05). Fish-oil treatment both enhanced VLDL binding and lowered LDL binding to fibroblasts. CONCLUSION: Treatment of hypertriglyceridemic patients with fish oil caused differential effects on VLDL subfractions and decreased LDL binding to fibroblast receptors, which may have contributed to the paradoxical increase in LDL-cholesterol concentrations.
Apolipoproteins B↗
Water-soluble hexasulfobutyl [60] fullerene inhibits plasma lipid peroxidation by direct association with lipoproteins.
Free radicals can induce lipid peroxidation, leading to the formation of atherosclerosis. A new class of water-soluble C60 derivative, hexasulfobutyl [60] fullerene [C60-(CH2CH2CH2CH2SO3Na)6; (FC4S)], comprising six sulfobutyl functional groups covalently bound on a C60 cage, is a potent free radical scavenger. This study sought to define the effect of FC4S in protecting plasma from peroxidation. At concentrations of 10-100 microM, FC4S efficiently protected plasma against Cu2+-induced oxidation, as shown by maintenance of apoprotein B integrity and decrease in oxidative products levels, conjugated diene, and thiobarbituric acid-reactive substances. Addition of FC4S to both plasma and isolated lipoproteins, including very low density, low-density, and high-density lipoproteins, resulted in an increased mobility of the lipoprotein on agarose gel electrophoresis. This was attributed to FC4S associating with the lipoproteins because of the negative charge of the sulfonate groups after hydrolysis in the electrophoretic buffer. When lipoprotein was oxidized by 2,2-azobis (2,4-dimethyl-valeronitrile), which produces peroxyl radicals within lipoprotein, but not in the aqueous phase, the FC4S still efficiently inhibited lipoprotein oxidation. These data substantiate that FC4S acts efficiently in protecting plasma lipid from oxidation by associating with lipoprotein to scavenge free radicals in both the aqueous and lipophilic phases.
Apolipoproteins B↗
Exercise shifts the platelet aggregation modulatory role from native to mildly oxidized low-density lipoprotein.
PURPOSE: The role of low-density lipoprotein (LDL) lipid peroxides in strenuous exercise-induced changes in platelet function was studied in 30 patients (male/female = 22/8) aged 30-62 yr (mean +/- SD = 508). METHODS: All subjects were subjected to a treadmill exercise test, using the standard Bruce protocol. Blood samples were collected pre-, peak, and 10 min postexercise to assess hematological and biochemical parameters and platelet aggregation. Ex vivo whole blood platelet aggregation during treadmill exercise was assessed in 10 subjects by adding mildly oxidized LDL. RESULTS: Preexercise, a correlation existed between plasma thromboxane (TX) levels and plasma LDL cholesterol or beta-thromboglobulin (beta-TG) levels (r = 0.48, P < 0.05: r = 0.47, P < 0.05, respectively), whereas, at peak exercise, TX and beta-TG levels increased, but no correlation was seen. At peak exercise, platelets showed hyperaggregability in terms of maximal amplitude and reaction slope (P < 0.001 and P < 0.01, respectively). In contrast to the increase in plasma lipid peroxide levels seen during peak exercise (P < 0.05), LDL lipid peroxides decreased during exercise, this decrease reaching a statistical significance at 10 min postexercise (P < 0.05). In addition, the ex vivo addition of mildly oxidized LDL (10 mg protein x L(-1)) to peak exercise blood resulted in a significant attenuation of platelet aggregation and a decrease in TX release. At 10 min postexercise, a correlation was seen between LDL lipid peroxides and TX levels (r = 0.78, P < 0.001) or beta-TG levels (r = 0.68, P < 0.005). CONCLUSION: These results suggest that LDL lipid peroxides play a role in modulating and attenuating platelet aggregation during strenuous exercise.
Adult↗
Apparent ventricular bigeminy in the congenital long QT syndrome: what is the mechanism?
Explore the source record for details and available documents.
Action Potentials↗
Distension of urinary bladder induces exaggerated coronary constriction in smokers with early atherosclerosis.
Distension of the urinary bladder causes an increase in efferent sympathetic activity, which can precipitate myocardial ischemia. Smoking has been shown to modulate activities of afferent nerves from the distended urinary bladder and to impair endothelial function in response to sympathetic activation. To assess the effect of bladder distension on coronary dynamics in smokers, we measured epicardial and microvascular responses in 24 patients with early atherosclerosis (< 50% diameter stenosis). Patients were classified into habitual smokers (group 1, n = 14) and nonsmokers (group 2, n = 10). Habitual smokers were randomized into two subgroups on the basis of the use of doxazosin, as follows: subgroup 1A (n = 7), without administration of doxazosin before catheterization; subgroup 1B (n = 7), with dosing doxazosin. In response to bladder distension (mean intravesical pressure 21.5 mmHg), bladder distension significantly decreased coronary diameter at the stenotic segments, coronary blood flow, and increased coronary resistance compared with baseline values, in subgroup 1A patients. In subgroup 1B patients during bladder distension, coronary diameter, coronary blood flow, and coronary resistance did not show significant changes compared with baseline values. There were significant differences of coronary diameter at the stenotic segments, coronary blood flow, and of changes of coronary vascular resistance between subgroup 1A and group 2 during bladder distension, despite similar changes in rate-pressure product. The present study showed that urinary bladder distension caused an abnormal vasomotor response of epicardial vasoconstriction and a concomitant increased coronary resistance, which leads to reduction in coronary blood flow in patients with early atherosclerosis. Smoking may further impair the response, implying that smoking has exaggerated response to sympathetic stimulation of conduit and resistance vessels. The abnormal response was abolished by pretreated administration of doxazosin, suggesting that the involved mechanisms are related to alpha(1)-adrenoceptors.
Aged↗
Integrated backscatter for quantification and risk stratification of blood stagnation in left atrial appendages of patients with rheumatic mitral stenosis.
This study was designed to quantify the blood stagnation in left atrial appendages (LAA) of patients with rheumatic mitral stenosis, and to stratify the risk of spontaneous echo contrast (SEC) for thrombus formation. A total of 45 patients were enrolled in this study. Thirty of the 45 patients had rheumatic mitral stenosis. All the above patients were evaluated for LAA contractility by transesophageal echocardiography. Acoustic density of the stagnant blood was assessed using the integrated backscatter (IBS) mode. Multivariate linear regression analysis showed that the significant independent variables determining relative IBS in LAA were the mitral valve area (p = 0.02) and the atrial fibrillation rhythm (p = 0.0003). In patients with mitral stenosis, the IBS in LAA correlated well with the presence of thrombus (p = 0.004) and SEC (p = 0.002). Using the relative IBS in LAA with 6.8 dB as the cutoff value, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy of SEC formation in LAA was 83, 86, 95, 60 and 83%, respectively. Using the relative IBS in LAA with 10.0 dB as the cutoff value, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy of SEC with thrombus formation in LAA was 80, 80, 67, 89 and 80%, respectively. In conclusion, the blood stasis in LAA can be objectively quantified using IBS. Utilizing different cutoff values, the acoustic densitometry in LAA enables identification of stagnant blood which represents a risk for the development of either SEC only or SEC with thrombus formation.
Adolescent↗
Amyotrophic lateral sclerosis with a 'pseudo-infarction' pattern on the electrocardiograph. A case report.
Amyotrophic lateral sclerosis (ALS) is a motor neuron disease involving both the upper and lower motor neurons in the brain stem and spinal cord. Although it is well known that various central nervous system disorders can produce a 'pseudo-infarction' pattern on the electrocardiogram, there have been no reports of this particular pattern in ALS patients. This report concerns an ALS patient who presented with an ECG pattern of S-T elevation followed by biphasic T and inverted T without any detectable myocardial abnormality. Data from the present case suggest that this pattern may be an inherent characteristic of ALS.
Amyotrophic Lateral Sclerosis↗
A randomized crossover evaluation of antianginal efficacy and safety of nitrolingual-spray and nitroglycerin tablet form in coronary artery disease patients.
Twenty-eight coronary artery disease patients with more than 50% stenosis in at least one major coronary artery completed this randomized crossover clinical trial for the comparison of efficacy and safety of Nitrolingual-Spray and nitroglycerin (NTG) tablets. Exercise time was lengthened to 399.1 s (spray) or 408.5 s (tablets), compared to a baseline of 387.3 s. Ischemic burden decreased to about -4.0 mm with both forms, compared to -7.5 mm at baseline (ANOVA: p = 0.003). The ischemic time improved to 137.2 s (spray) or 152.9 s (tablets), compared to 253.4 s at baseline (ANOVA: p = 0. 005). Patients taking tablets experienced more episodes of hypotension and/or headache compared to patients taking the spray. Nitrolingual-Spray is as effective and safe as NTG tablets for the treatment of symptomatic coronary heart disease.
Administration, Inhalation↗
Intraventricular isovolumic relaxation flow patterns improve the predicting power of Doppler echocardiography for the left ventricular filling pressure in patients with anterior wall myocardial infarction.
BACKGROUND AND PURPOSE: Previous studies have shown that left ventricular systolic asynchrony affects both the relaxation and filling phases of diastole. The purpose of this study was to delinate how the anterior wall dyssynergy influenced the intraventricular flow redistribution patterns during the isovolumic relaxation (IVR) period, which delineated the changes in diastolic suction performance and, therefore, determined the significant Doppler flow variables for predicting left ventricular filling pressure. METHODS: Seventy-three patients with anterior wall myocardial infarction and dyssynergy were enrolled. Those who exhibited the whole IVR intraventricular flow redistributing toward the mitral apparatus, which indicated the reverse physiologic intraventricular pressure gradient in early diastole, were classified as group B, otherwise, as group A. The Doppler echocardiographic variables of mitral inflow were correlated with the left ventricular end-diastolic pressures (LVEDP). RESULTS: With lower ejection fraction rate and more apical dyssynergy, the group B patients had much slower mitral flow propagation. For group A patients, the independent determinants for LVEDP were the ratio of mitral flow propagation rate to peak velocity in early diastole, the early mitral flow deceleration time and the IVR time, all occurring in early diastole. In contrast, the only independent determinant for LVEDP in group B patients was the ratio of mitral peak flow velocity in early diastole to that in late diastole. CONCLUSIONS: The intraventricular IVR flow patterns could delineate how the left ventricular systolic dyssynergy influenced the diastolic process, and determine which echocardiographic variables were more useful for predicting LVEDP in patients with anterior wall myocardial infarction.
Adult↗
Impairment of cerebrovascular reactivity by methionine-induced hyperhomocysteinemia and amelioration by quinapril treatment.
BACKGROUND AND PURPOSE: Human studies have shown that methionine-induced hyperhomocysteinemia impairs brachial artery endothelial function via decreasing nitric oxide activity. However, the effect of homocysteine on cerebrovascular reactivity (CVR), which has been reported to be nitric oxide related in experimental and animal studies, remains unclear in humans. Inhibition of angiotensin-converting enzyme may improve nitric oxide-mediated cerebral as well as peripheral endothelial function. The aim of the present study was to investigate the effect of methionine-induced hyperhomocysteinemia on CVR before and after treatment with quinapril, an angiotensin-converting enzyme inhibitor, in healthy adults. METHODS: Plasma homocysteine and CVR were measured at baseline and 4 hours after methionine load (0.1 g/kg body wt) before and after quinapril treatment (10 mg/d for 1 week) in both younger and older groups. CVR was assessed by transcranial Doppler ultrasonography, measuring the percent increase of flow velocity in the middle cerebral artery after brief carotid compression (expressed as transient hyperemic response ratio [THRR]). RESULTS: Homocysteine levels were significantly increased after methionine load either before or after quinapril treatment in both groups. Before quinapril treatment, postmethionine THRR was preserved in younger adults (24.2+/-5.3% versus 23.8+/-6.3% at baseline, P:=0.73) and decreased in older adults (12.9+/-2.2% versus 21.8+/-4.0% at baseline, P:<0.001). After quinapril treatment, postmethionine THRR was preserved in both groups (24.5+/-5.9% versus 24.0+/-5.0% at baseline, P:=0.42 in younger adults; 20.4+/-3.9% versus 21.3+/-3.3% at baseline, P:=0.35 in older adults). CONCLUSIONS: Our study suggests that methionine-induced hyperhomocysteinemia may be causally associated with impairment of CVR in older normal subjects.
Adult↗