Association of resting left ventricular global longitudinal strain with myocardial perfusion abnormalities evaluated by 13 N-ammonia positron emission tomography in patients with stable angina pectoris and normal left ventricular ejection fraction.

AIMS: Little is known about whether resting left ventricular global longitudinal strain (GLS) impairment is associated with myocardial perfusion abnormalities evaluated using 13 N-ammonia positron emission tomography (13 N-NH3 -PET)-myocardial perfusion imaging (MPI). This study aimed to investigate the correlation between resting GLS and myocardial perfusion parameters in patients with a normal left ventricular ejection fraction (LVEF). We evaluated whether resting GLS can predict myocardial perfusion abnormalities in these patients. METHODS AND RESULTS: We selected 157 patients with suspected stable angina pectoris who underwent both ATP-stress NH3 -PET-MPI and 2-dimentional speckle tracing echocardiography. All subjects had a preserved LVEF and no known history of myocardial infarction. Patients were stratified into Group N (normal perfusion; summed stress score [SSS], 0-3; n = 101), Group M (mildly to moderately abnormal perfusion; SSS, 4-11; n = 41), or Group S (severely abnormal perfusion; SSS, 12+; n = 15). GLS was more impaired as myocardial perfusion abnormality severity increased (-17.9 ± 2.9% for Group N, -16.8 ± 3.1% for Group M, and -14.2 ± 3.5% for Group S; p < .001). GLS was weakly but significantly correlated with SSS (R = .32, p < .001), summed difference score (R = .32, p < .001), and myocardial blood flow during stress (R = -0.27, p < .001). Multivariate logistic regression analysis showed that male sex, diabetes mellitus, systolic blood pressure, and GLS were independent predictors of myocardial perfusion abnormality defined as Groups M and S. Additionally, the area under the curve for GLS for detecting myocardial perfusion abnormality was .65, and the optimal cutoff value for GLS was -16.5%, with sensitivity and specificity of 59% and 66%, respectively. CONCLUSION: In patients with suspected angina pectoris, resting GLS impairment despite a normal LVEF might aid the detection of hemodynamically significant coronary artery disease.

Occludin induces microvillus formation via phosphorylation of ezrin in a mouse hepatic cell line.

Apical and basolateral cell membranes are separated by tight junctions (TJs). Microvilli are limited to the apical cell membrane. TJs and microvilli are the landmarks for epithelial cell polarity. However, the direct relationship between TJ proteins (TJPs) and the components of microvilli remains unclear. In this study, we investigated whether occludin, which is considered to be a functional TJP, is involved in microvillus formation. In occludin knockout mouse hepatic cells (OcKO cells), the microvillus density was less than that in wild-type (WT) cells and the length of microvilli was short. Immunoreactivity of ezrin was decreased in OcKO cells compared with that in WT cells. Although there was no change in the expression level of ezrin, phosphorylation of ezrin was decreased in OcKO cells. The microvillus density and the length of microvilli were increased in OcKO cells by transfection of full-length mouse occludin and COOH-terminal domains of occludin. These results suggested that occludin induced microvillus formation via phosphorylation of ezrin and that the COOH-terminal domain of occludin, which is localized in non-TJ areas, might be able to induce microvilli formation. Our results provide new insights into the function of occludin.

Resting echocardiographic parameters to detect patients with less symptomatic primary mitral regurgitation who require exercise stress echocardiography.

Objectives: We aimed to identify which resting echocardiographic parameters can detect asymptomatic or mildly symptomatic patients with primary mitral regurgitation (MR) who require exercise stress echocardiography (ESE) to determine their suitability for surgery. Methods: We examined 56 consecutive patients with primary moderate/severe MR who underwent ergometer-based ESE. Patients who met the surgical indications at rest were excluded. Eligible patients were divided into Group I (pulmonary artery systolic pressure [PASP] during exercise >60 mmHg; n=11) and Group II (PASP during exercise ≤60 mmHg; n=30). Results: Forty-one patients were included. Group I was significantly older (65±12 vs. 54±14 years, P=0.042) and had significantly higher serum N-terminal pro-B-type natriuretic peptide concentrations than Group II (351±278 vs. 125±163 pg/mL, P=0.002). The univariate analysis demonstrated that peak E wave velocity (Group I vs. Group II: 125±45 vs. 101±24 cm/sec, P=0.050), left ventricular (LV) end-diastolic diameter index (32±4 vs. 30±3 mm/m2, P=0.035), and left atrial volume index (LAVI; 45±14 vs. 30±11 mL/m2, P=0.008) were predictors of increased PASP during exercise. In the multivariate analysis, resting LAVI best predicted exercise-induced pulmonary hypertension (hazard ratio 1.081 [95% confidence interval 1.009-1.158], P=0.028), with a cutoff value of 37 mL/m2. Conclusions: In asymptomatic or mildly symptomatic patients with primary moderate/severe MR, increased resting LAVI indicates the requirement for ESE, even without LV dilatation.

Age-related etiologies of aortic regurgitation with moderate or greater severity and coronary cusp bending: evaluation using transesophageal echocardiography.

PURPOSE: The prevalence of valvular heart disease has been rising, especially among those ≥ 65 years of age, because of age-related valvular degeneration resulting in an increase in the number of patients diagnosed with aortic regurgitation (AR). We analyzed transesophageal echocardiography (TEE) images in AR patients to identify the etiologies and investigate any differences in them according to age. METHODS: We studied 146 consecutive patients with chronic moderate or severe AR who underwent TEE. AR etiology was evaluated based on the TEE images in all the patients, as well as in each group separated by age. RESULTS: The total number of patients eligible was 126 (mean age 67 ± 12 years), consisting of an older group (n = 85, mean age 74 ± 5 years) and younger group (n = 41, mean age 52 ± 11 years). In total, the most common etiology of AR was cusp bending (33.0%). In the older group, it was the most frequent as well (48.2%), with the right coronary cusp being the most commonly affected site (90.2%). In the younger group, bicuspid aortic valve was the most common (36.5%). Subsequently, all the study subjects were re-classified into two groups according to the presence/absence of cusp bending. Multivariate analysis revealed that age was the only factor associated with cusp bending. CONCLUSION: Cusp bending was the most frequent etiology of AR in the elderly. Preoperative detection of cusp bending by TEE would expand the therapeutic strategy for AR, including aortic valvuloplasty.

Hydrolyzed guar gum decreases postprandial blood glucose and glucose absorption in the rat small intestine.

We hypothesized that infusing partially hydrolyzed guar gum (PHGG) into the duodenum would reduce increases in postprandial plasma glucose by decreasing the rate of glucose diffusion from the small intestine luminal digesta of the rat. The postprandial plasma glucose and apparent glucose disappearance from the small intestine were measured after infusing artificial digesta containing 0 (control), 3.0, or 6.0 g/L PHGG into the duodenum via a cannula under anesthesia in experiments 1 and 2. The diffusion of glucose in the artificial digesta was estimated using dialysis tubing, filled with the same artificial digesta, soaked in a buffer in experiment 3. In experiment 1, the plasma glucose concentration was lower in the digesta containing 3.0 and 6.0 g/L PHGG than in the control digesta at 120 minutes (P < .05). The plasma insulin concentration was lower for the digesta containing 6.0 g/L PHGG than for the control digesta at 60 minutes (P < .05) and lower for the digesta containing 6.0 g/L PHGG than for that containing 3.0 g/L PHGG at 120 minutes (P < .05).The area under the curve of plasma glucose and insulin (experiment 1), apparent disappearance of glucose in the lumen of the small intestine (experiment 2), and net disappearance of glucose in the dialysis tube depended negatively on the viscosity of the artificial digesta (P < .05, .05, .001, and .05), which was increased by adding PHGG. Therefore, PHGG can decrease the postprandial blood glucose by lowering the rate of absorption from the small intestine in the rat by reducing the diffusion of glucose in the lumen.