Hsueh-Wen Chang

Level and Value of Circulating Endothelial Progenitor Cells in Patients After Acute Ischemic Stroke

Background and Purpose— Endothelial progenitor cells (EPCs) migrate from bone marrow to systemic circulation in response to tissue ischemia where they differentiate into mature endothelial cells for angiogenesis in situ. This study tested the hypothesis that the level of circulating EPCs is substantially increased and predictive of prognostic outcomes after acute ischemic stroke (IS). Methods— The level of circulating EPCs (staining markers: CD31/CD34 [E1], CD62E/CD34 [E2], and KDR/CD34 [E3]) were examined using flow cytometry at 48 hours after acute IS in 138 consecutive patients. The EPC level was also evaluated once in 20 healthy volunteers and in 40 at-risk control subjects. Results— Level of circulating EPCs (E1–3) was significantly higher in patients with IS than in at-risk control subjects (P<0.05). Additionally, EPC (E1–3) level was significantly lower in patients with severe neurological impairment (defined as a score ≥12 on the National Institutes of Health Stroke Scale) than in patients with less severe impairment (National Institutes of Health Stroke Scale < score 12) at 48 hours after IS (P<0.0001). Moreover, the EPC (E3) level was strongly correlated with improved National Institutes of Health Stroke Scale ≥4 on day 21 after IS (P=0.0004). Furthermore, low circulating EPC level was independently predictive of severe neurological impairment (National Institutes of Health Stroke Scale ≥12) at 48 hours (E1–3) and combined major adverse clinical outcomes (defined as recurrent IS, any cause of death, or National Institutes of Health Stroke Scale of ≥12) on day 90 (E1) after IS (P<0.001). Conclusions— Level of circulating EPCs is independently predictive of prognosis after IS.

Melatonin treatment improves adipose-derived mesenchymal stem cell therapy for acute lung ischemia–reperfusion injury

This study investigated whether melatonin‐treated adipose‐derived mesenchymal stem cells (ADMSC) offered superior protection against acute lung ischemia–reperfusion (IR) injury. Adult male Sprague‐Dawley rats (n = 30) were randomized equally into five groups: sham controls, lung IR–saline, lung IR–melatonin, lung IR–melatonin–normal ADMSC, and lung IR–melatonin–apoptotic ADMSC. Arterial oxygen saturation was lowest in lung IR–saline; lower in lung IR–melatonin than sham controls, lung IR–melatonin–normal ADMSC, and lung IR–melatonin–apoptotic ADMSC; lower in lung IR–melatonin–normal ADMSC than sham controls and lung IR–melatonin–apoptotic ADMSC; lower in lung IR–melatonin–apoptotic ADMSC than sham controls (P < 0.0001 in each case). Right ventricular systolic blood pressure (RVSBP) showed a reversed pattern among all groups (all P < 0.0001). Changes in histological scoring of lung parenchymal damage and CD68+ cells showed a similar pattern compared with RVSBP in all groups (all P < 0.001). Changes in inflammatory protein expressions such as VCAM‐1, ICAM‐1, oxidative stress, TNF‐α, NF‐κB, PDGF, and angiotensin II receptor, and changes in apoptotic protein expressions of cleaved caspase 3 and PARP, and mitochondrial Bax, displayed identical patterns compared with RVSBP in all groups (all P < 0.001). Numbers of antioxidant (GR+, GPx+, NQO‐1+) and endothelial cell biomarkers (CD31+ and vWF+) were lower in sham controls, lung IR–saline, and lung IR–melatonin than lung IR–melatonin–normal ADMSC and lung IR–melatonin–apoptotic ADMSC, and lower in lung IR–melatonin–normal ADMSC than lung IR–melatonin–apoptotic ADMSC (P < 0.001 in each case). In conclusion, when the animals were treated with melatonin, the apoptotic ADMSC were superior to normal ADMSC for protection of lung from acute IR injury.

Plasma nuclear and mitochondrial DNA levels as predictors of outcome in severe sepsis patients in the emergency room

Background and aimThe sensitivity and specificity of biomarkers and scoring systems used for predicting fatality of severe sepsis patients remain unsatisfactory. This study aimed to determine the prognostic value of circulating plasma DNA levels in severe septic patients presenting at the Emergency Department (ED).MethodsSixty-seven consecutive patients with severe sepsis and 33 controls were evaluated. Plasma DNA levels were estimated by real-time quantitative polymerase chain reaction assay using primers for the human β-hemoglobin and ND2 gene. The patients’ clinical and laboratory data on admission were analyzed.ResultsThe median plasma nuclear and mitochondria DNA levels for severe septic patients on admission were significantly higher than those of the controls. The mean plasma nuclear DNA level on admission correlated with lactate concentration (γ = 0.36, p = 0.003) and plasma mitochondrial DNA on admission (γ = 0.708, p < 0.001). Significant prognostic factors for fatality included mechanical ventilation within the first 24 hours (p = 0.013), mean sequential organ failure assessment (SOFA) score on admission (p = 0.04), serum lactate (p < 0.001), and both plasma nuclear and mitochondrial DNA on admission (p < 0.001). Plasma mitochondrial DNA was an independent predictor of fatality by stepwise logistic regression such that an increase by one ng/mL in level would increase fatality rate by 0.7%.ConclusionPlasma DNA has potential use for predicting outcome in septic patients arriving at the emergency room. Plasma mitochondrial DNA level on admission is a more powerful predictor than lactate concentration or SOFA scores on admission.

Normal tension glaucoma in patients with obstructive sleep apnea/hypopnea syndrome.

PurposeTo determine the prevalence of normal tension glaucoma (NTG) in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) and further investigate whether the severity of OSAHS would increase the risk of glaucoma. Patients and MethodsTwo hundred fifty-six participants were consecutively admitted for polysomnographic exam to diagnose OSAHS. All participants, then underwent a complete ophthalmologic evaluation, including best-corrected visual acuity, intraocular pressure, slit lamp biomicroscopy, gonioscopy, fundoscopy, automated visual field (VF), and retinal nerve fiber layer (RNFL) evaluation. ResultsA total of 247 participants were enrolled in the study. Two hundred nine patients were OSAHS and 38 participants were classified as the normal group. Among the OSAHS patients, NTG was found in 12 patients with a prevalence of 5.7%, which was higher than that in the normal group (P=0.003). In the NTG patients, 1 was in the mild, 3 were in the moderate, and 8 were in the severe OSAHS group. There was no glaucoma patient in the normal group. The prevalence of NTG in moderate/severe OSAHS patients was 7.1%, significantly higher (P=0.033) than that in normal/mild OSAHS patients. The mean saturation of oxygen and lowest saturation of oxygen correlated with the average thickness of RNFL in the OSAHS patients. ConclusionsPatients with OSAHS had a high prevalence of NTG, especially in patients with moderate and severe OSAHS. The severity of OSAHS inversely correlated with retinal nerve fiber layer thickness. Clinicians need to consider the possibility of glaucoma in patients with moderate and severe OSAHS.

Serial Changes in Platelet Activation in Patients After Ischemic Stroke Role of Pharmacodynamic Modulation

Background and Purpose— Enhanced platelet activity has previously been reported in the acute phase after ischemic stroke. We tested the hypothesis that activated platelets (expressed by CD62p) are substantially increased in the acute stage after a stroke and decrease thereafter, and that antiplatelet therapies can suppress CD62p expression. Methods— We serially examined platelet CD62p expression using flow cytometry after acute ischemic stroke in 87 consecutive patients. The CD62p expression was also evaluated in 20 healthy volunteers and 33 at-risk control subjects. Results— CD62p expression was significantly higher in the acute phase after ischemic stroke than in normal and at-risk control subjects (both P < 0.0001). CD62p expression decreased to a significantly lower level on day 21, and to a substantially lower level on day 90. CD62p expression was not significantly suppressed by warfarin. However, CD62p expression was significantly suppressed by aspirin treatment (P = 0.024) and more substantially suppressed by clopidogrel (P < 0.0001) on day 90. Furthermore, only clopidogrel treatment (P = 0.0016) was significantly independently associated with decreased CD62p expression on day 90. Conclusions— Platelet activation was significantly increased in acute ischemic stroke and substantially decreased thereafter. The lesser long-term pharmacodynamic potency of aspirin relative to clopidogrel raises the prospect of the need for more effective antiplatelet agents or a synergistic combination therapy for stroke prevention in the future.

Risk Stratification of In-Hospital Mortality in Patients Hospitalized for Chronic Congestive Heart Failure Secondary to Non-Ischemic Cardiomyopathy

The study population consisted of 234 consecutive patients hospitalized for acute exacerbation of congestive heart failure secondary to non-ischemic cardiomyopathy. Of the 234 patients, there were 55 in-hospital deaths. Their medical records were deliberatively reviewed and the association of 38 clinical, hemodynamic and biochemical variables with in-hospital mortality was evaluated by multiple stepwise logistic regression analysis. The following variables were statistically associated with in-hospital mortality: profound cardiogenic shock, severe hyponatremia, the presence of ventricular arrhythmias, history of stroke, the presence of acute renal failure, and requirement of dobutamine therapy. In stratified analyses, the rates of in-hospital mortality rose rapidly as the number of risk factors increased: 0 risk factors, 2.5%; 1 risk factor, 5.1%; 2 risk factors, 36.4%; 3 risk factors, 75%, and no less than 4 risk factors, 100%. In conclusion, our study identified 6 variables that correlated with in-hospital death in patients with heart failure secondary to non-ischemic cardiomyopathy. The identification of these variables may allow more accurate risk stratification of individuals at risk of in-hospital mortality in this clinical setting.

Effect of obesity reduction on preservation of heart function and attenuation of left ventricular remodeling, oxidative stress and inflammation in obese mice

BackgroundObesity is an important cardiovascular risk factor. This study tested the effect of obesity reduction on preserving left ventricular ejection fraction (LVEF) and attenuating inflammation, oxidative stress and LV remodeling in obese mice.Methods and resultsEight-week-old C57BL/6 J mice (n=24) were equally divided into control (fed a control diet for 22 weeks), obesity (high-fat diet, 22 weeks), and obese reduction (OR) (high-fat diet, 14 weeks; then control diet, 8 weeks). Animals were sacrificed at post 22-week high-fat diet and the LV myocardium collected. Heart weight, body weight, abdominal-fat weight, total cholesterol level and fasting blood glucose were higher in obesity than in control and OR (all p<0.001). Inflammation measured by mRNA expressions of IL-6, MMP-9, PAI-1 and leptin and protein expression of NF-κB was higher, whereas anti-inflammation measured by mRNA expressions of adiponectin and INF-γ was lower in obesity than in control and OR (all p<0.003). Oxidative protein expressions of NOX-1, NOX-2 and oxidized protein were higher, whereas expression of anti-oxidant markers HO-1 and NQO-1 were lower (all p<0.01); and apoptosis measured by Bax and caspase 3 was higher, whereas anti-apoptotic Bcl-2 was lower in obesity as compared with control and OR (all p<0.001). The expressions of fibrotic markers phosphorylated Smad3 and TGF-β were higher, whereas expression of anti-fibrotic phosphorylated Smad1/5 and BMP-2 were lower (all p<0.02); and LVEF was lower, whereas the LV remodeling was higher in obesity than in control and OR (all p<0.001).ConclusionImpaired LVEF, enhanced LV remodeling, inflammation, fibrosis, oxidative stress and apoptosis were reversed by reduction in mouse obesity.

Link between Platelet Activity and Outcomes after an Ischemic Stroke

Background: Platelets play an important role in atherosclerosis and thromboembolic events. We examined the relationship between platelet activity and outcomes after an ischemic stroke. Methods: Using flow cytometry, we serially measured the fractions of circulating platelet activity (CD62p expression) after an ischemic stroke in early (<48 h), recent (day 7), convalescent (day 21) and chronic (day 90) phases in 92 consecutive patients with an ischemic stroke. Patients were classified into high (CD62p expression >3.16%) and low (CD62p expression ≤3.16%) platelet activity groups according to the median value of CD62p expression in the early phase of a stroke. Results: The composite end point – death, recurrent stroke and severe neurological impairment (alive in care), defined as a score of >13 on the National Institutes of Health Stroke Scale – within the first 30 days and at an interval of 8.2 ± 1.5 months of follow-up was determined for each group. In the first 30 days, the composite end point occurred in 37.0% of patients in the high platelet activity group as compared with 6.5% in the low platelet activity group (p = 0.0004). At a mean follow-up of 8.2 ± 1.5 months, the composite end point occurred in 36.6% of patients in the high platelet activity group as compared with 10.9% in the low platelet activity group (p = 0.0044). Multiple stepwise logistic regression analysis displayed that high platelet activity (p = 0.011), age (p = 0.013) and the presence of coronary artery disease (p = 0.021) were independently associated with adverse outcomes at the intermediate-term follow-up. Conclusions: Results of this study showed that high platelet activity is strongly associated with adverse clinical outcomes after an early ischemic stroke.

Left Atrial Platelet Activity With Rheumatic Mitral Stenosis: Correlation Study of Severity and Platelet P-Selectin Expression by Flow Cytometry

BACKGROUND Previous studies have demonstrated that platelet activation, evaluated by measuring the secretory substances of platelets (ie, platelet factor 4 and beta-thromboglobulin), occurs in the peripheral blood of patients with rheumatic mitral stenosis (MS). However, the differences in platelet activation between peripheral and atrial blood, and the relationship between regional left atrial platelet P-selectin expression and the severity of MS have never been investigated. METHODS AND RESULTS A total of 16 patients with symptomatic MS undergoing percutaneous transluminal mitral valvuloplasty were studied (group 1). The fractions of platelets expressing P selectin in the prevalvuloplasty left atrial, right atrial, peripheral venous, and arterial blood were determined by flow cytometry. The mitral valve area was calculated by means of the Doppler pressure half-time method. Peripheral venous platelet activity also was evaluated in 23 control patients (including 15 healthy volunteers who were in sinus rhythm [group 2] and 8 patients who had chronic lone atrial fibrillation [group 3]). The fraction of peripheral venous platelets expressing P selectin among group 1 patients was significantly higher than that of group 2 or 3 patients (p = 0.008). In group 1 patients, the fraction of platelets expressing P selectin in the left atrium was significantly higher than that in the right atrium, the femoral vein, or the femoral artery (p < 0.01). Correlation analysis demonstrated that there was a significantly direct relationship between the severity of MS and the fraction of left atrial platelets expressing P selectin (p = 0.01; r = -0.620). The fraction of peripheral venous platelets expressing P selectin among group 2 patients did not differ from that of group 3 patients CONCLUSIONS In patients with rheumatic MS, increased regional left atrial platelet P-selectin expression had a significantly direct relationship with the severity of MS. The increased regional left atrial platelet P-selectin expression was not reflected in peripheral venous blood samples.

Atrial myocardial nox2 containing NADPH oxidase activity contribution to oxidative stress in mitral regurgitation: potential mechanism for atrial remodeling

BACKGROUND Oxidative stress is linked with several cardiovascular diseases. However, the NADPH oxidase activity in severe mitral regurgitation patients with and without atrial fibrillation has not yet been explored. METHODS This study involved 16 adult patients (eight patients with persistent atrial fibrillation and eight with sinus rhythm) with severe mitral and moderate-to-severe tricuspid regurgitation and five control patients without mitral and tricuspid disease. Atrial tissues of the right and left atrial appendages were obtained during surgery. Superoxide anion production was measured by lucigenin-enhanced chemiluminescence, and the expression of nox2 containing NADPH oxidase mRNA was measured by quantitative real-time RT-PCR. Additionally, immunohistochemical study was performed. RESULTS NADPH-stimulated superoxide release was significantly higher than basal superoxide production from right [5671.9±3498.7 vs. 232.7±70.0 relative light units per second per milligram of protein (RLU s(-1) mg protein(-1)), P=.008) and left atrial homogenates (6475.1±1890.8 vs. 229.0±79.6 RLU s(-1) mg protein(-1), P=.008) in atrial fibrillation patients. The NADPH-stimulated superoxide release from right atrial homogenates was also significantly higher than basal superoxide production in sinus patients (6809.1±1327.1 vs. 244.2±65.5 RLU s(-1) mg protein(-1), P=.008). Additionally, there was a borderline significant correlation between NADPH-stimulated superoxide production from left atrial homogenates and left atrial sizes (r=0.683, P=.062) in atrial fibrillation patients. Membrane-bound nox2 containing NADPH oxidase mRNA expression was increased and was similar in both the atrial fibrillation patients and sinus patients. The NADPH-stimulated superoxide production in right atrial homogenates in control atrial samples was 1863.7±137.2 RLU s(-1) mg protein(-1). Immunohistochemical study demonstrated increased expression of nox2 in myocytes with moderate-to-severe myolysis and hypertrophy. CONCLUSIONS Results of this study demonstrate that membrane-bound nox2 containing NADPH oxidase activity and expression in the atrial myocardium is increased in patients with severe mitral regurgitation, possibly contributing to atrial remodeling in this clinical setting.