Jong-Wei Lin

Efficacy of fenofibrate and simvastatin on endothelial function and inflammatory markers in patients with combined hyperlipidemia: relations with baseline lipid profiles

Given that combination therapy with statin plus fibrate confers a risk of myopathy, it is worthwhile to determine whether statin or fibrate monotherapy is associated with greater clinical benefit in individuals with combined hyperlipidemia. In this randomized double-blind study, we compared the efficacy of simvastatin and fenofibrate on indexes of endothelial function (flow-mediated dilation (FMD) of the brachial artery) and inflammatory markers (plasma high-sensitivity C-reactive protein (CRP), interleukin-1 beta (IL-1 beta), soluble CD40, and soluble CD40 ligand (sCD40L) levels), as surrogate indicators of future coronary heart disease (CHD), in patients with combined hyperlipidemia. A total of 70 patients with plasma triglyceride levels between 200 and 500 mg/dl and total cholesterol levels of >200 mg/dl were randomly assigned to receive either simvastatin (20 mg/day) (n=35) or micronized fenofibrate (200 mg/day) (n=35) for 8 weeks. Treatment with simvastatin was associated with significantly greater reduction of total cholesterol and low-density lipoprotein cholesterol (LDL-C), while the decrease in triglycerides was significantly greater in patients receiving fenofibrate. Both fenofibrate and simvastatin markedly reduced plasma levels of high-sensitivity CRP, IL-1 beta, and sCD40L, and improved endothelium-dependent FMD without mutual differences. The changes in plasma inflammatory markers did not correlate with baseline clinical characteristics in both groups. However, the improvement in FMD with fenofibrate treatment correlated inversely with baseline high-density lipoprotein cholesterol (HDL-C) levels, whereas the improvement in FMD with simvastatin treatment was positively related to HDL-C levels. Accordingly, in the subgroup with a baseline HDL-C of < or =40 mg/dl, only fenofibrate significantly improved the endothelium-dependent FMD. On the other hand, in the subgroup with HDL-C >40 mg/dl, only treatment with simvastatin achieved significant improvement in FMD. The data here indicate that in patients with combined hyperlipidemia, both fenofibrate and simvastatin have comparative beneficial effects on various inflammatory markers and differential beneficial effects on endothelial function according to baseline HDL-C levels. These findings should be validated by additional prospective studies, in which patients are stratified by baseline HDL-C prior to randomization.

Attenuation of increased myocardial ischaemia-reperfusion injury conferred by hypercholesterolaemia through pharmacological inhibition of the caspase-1 cascade

Hypercholesterolaemia has been shown to be associated with greater myocardial ischaemia‐reperfusion injury, in which apoptosis and inflammation‐mediated necrosis both play a key role. Caspase‐1 is involved in the activation of both apoptosis and inflammation, through the intermediate of interleukin‐1β (IL‐1β). We herein examined whether pharmacological inhibition of the caspase‐1 cascade, using Ac‐Tyr‐Val‐Ala‐Asp‐CH2Cl (Ac‐YVAD.cmk), after myocardial ischaemia have greater protective effects on myocardial ischaemia‐reperfusion injury in diet‐induced hypercholesterolaemic rabbits. Male rabbits fed with standard chow or chow supplemented with 0.5% cholesterol and 10% coconut oil for 8 weeks were subjected to 30 min of left circumflex artery occlusion followed by 4 h of reperfusion. An intravenous bolus of Ac‐YVAD.cmk (1.6 mg kg−1) or vehicle was given 20 min after coronary occlusion. Postischaemic administration of Ac‐YVAD.cmk markedly decreased infarct size from 26±3% to 12±2% in normally fed rabbits (P=0.005) and from 41±6% to 14±2% in cholesterol‐fed rabbits (P<0.001). In the ischaemic non‐necrotic area, treatment with Ac‐YVAD.cmk markedly reduced the percentage of terminal deoxynucleotidyl transferase‐mediated dUTP‐biotin nick end labelling (TUNEL)‐positive cardiomyocytes from 15.5±0.8% to 2.2±0.1% in normally fed rabbits (P<0.001) and from 39.0±2.3% to 2.2±0.1% in cholesterol‐fed rabbits (P<0.001). Ac‐YVAD.cmk treatment resulted in a reduction not only of IL‐1β and caspase‐1, but also of caspase‐3 in the ischaemic myocardium in both normally fed and cholesterol‐fed rabbits. No differences in infarct size, the percentage of TUNEL‐positive cardiomyocytes, IL‐1β levels or activity of caspase‐1 and caspase‐3 were observed between Ac‐YVAD.cmk‐treated normally fed and cholesterol‐fed rabbits. This study demonstrates that injection of a selective caspase‐1 inhibitor after myocardial ischaemia markedly reduced the detrimental effect conferred by hypercholesterolaemia on myocardial ischaemia‐reperfusion injury by attenuating both necrotic as well as apoptotic cell death pathways through inhibition of IL‐1β production and activation of caspase‐1 and caspase‐3.

Imaging Cytometry of Human Leukocytes with Third Harmonic Generation Microscopy

Based on third-harmonic-generation (THG) microscopy and a k-means clustering algorithm, we developed a label-free imaging cytometry method to differentiate and determine the types of human leukocytes. According to the size and average intensity of cells in THG images, in a two-dimensional scatter plot, the neutrophils, monocytes, and lymphocytes in peripheral blood samples from healthy volunteers were clustered into three differentiable groups. Using these features in THG images, we could count the number of each of the three leukocyte types both in vitro and in vivo. The THG imaging-based counting results agreed well with conventional blood count results. In the future, we believe that the combination of this THG microscopy-based imaging cytometry approach with advanced texture analysis of sub-cellular features can differentiate and count more types of blood cells with smaller quantities of blood.

In vivo metabolic imaging of insulin with multiphoton fluorescence of human insulin-Au nanodots.

Functional human insulin-Au nanodots (NDs) are synthesized for the in vivo imaging of insulin metabolism. Benefiting from its efficient red to near infrared fluorescence, deep tissue subcellular uptake of insulin-Au NDs can be clearly resolved through a least-invasive harmonic generation and two-photon fluorescence (TPF) microscope. In vivo investigations on mice ear and ex vivo assays on human fat tissues conclude that cells with rich insulin receptors have higher uptake of administrated insulin. Interestingly, the insulin-Au NDs can even permeate into lipid droplets (LDs) of adipocytes. Using this newly discovered metabolic phenomenon of insulin, it is found that enlarged adipocytes in type II diabetes mice have higher adjacent/LD concentration contrast with small-sized ones in wild type mice. For human clinical samples, the epicardial adipocytes of patients with diabetes and coronary artery disease (CAD) also show elevated adjacent/LD concentration contrast. As a result, human insulin-Au nanodots provide a new approach to explore subcellular insulin metabolism in model animals or patients with metabolic or cardiovascular diseases.

Residual platelet reactivity after aspirin and clopidogrel treatment predicts 2-year major cardiovascular events in patients undergoing percutaneous coronary intervention

BACKGROUND Studies on the prognostic significance of residual platelet reactivity despite the use of dual anti-platelet agents are limited and seldom extend beyond 1year. METHODS This study enrolled 144 patients treated with standard-dose aspirin and clopidogrel and undergoing percutaneous coronary intervention (PCI). Platelet reactivity was measured by the Platelet Function Analyzer-100 (PFA-100) just before PCI and presented as collagen/epinephrine closure time (CEPI-CT) and collagen/adenosine diphosphate closure time (CADP-CT). Primary endpoint included cardiovascular death, myocardial infarction, and stroke. Secondary endpoint was the primary endpoint plus hospitalization due to unstable angina or urgent target vessel revascularization. RESULTS During the 24-month follow-up, 14 patients (9.7%) developed the primary endpoint events and 33 had the secondary endpoints. After controlling possible confounding factors, both CEPI-CT <193s and CADP-CT <95s were independently predictive of the primary endpoint (hazard ratio=3.5; 95% confidence interval: 1.04-11.7; p=0.044 and 5.3; 1.4-20.1; p=0.015, respectively). Only CADP-CT <95s remained significantly predictive of secondary endpoints in the follow-up periods of 0-9 and 9-24months, during which clopidogrel was mostly discontinued. CONCLUSION This study demonstrates that increased residual platelet reactivity measured by PFA-100 CADP-CT consistently predicts the occurrence of cardiovascular events following PCI throughout the 24-month follow-up period, irrespective of the changes in anti-platelet use.

Virtual optical biopsy of human adipocytes with third harmonic generation microscopy.

Using the sectioning capability of third harmonic generation (THG) microscopy, we assessed the morphologic features of human adipocytes directly without fixation and labeling. At the plane of the largest cross-sectional area, both area-equivalent circular diameters (AECD) and perimeters of adipocytes were measured, and their statistical distributions were examined. We found, in patients with no cardiovascular risk factors, the average AECD of epicardial adipocytes were 70–90 μm with 11–17 μm standard deviations. In contrast, for patients with coronary artery disease, amounts of small-sized (AECD <40 µm) epicardial adipocytes were observed and the corresponding standard deviations of AECD were increased to 20–29 μm. Our results indicate that the THG tomography platform can be used to explore the histopathological features of adipocytes in clinical scenarios based on its superior resolution for virtual optical biopsy.

Investigate the variation in optical redox ratio of epicardial adipose tissue in patients with CAD through auto-fluorescence metabolic molecular image(Conference Presentation)

In recent years, it has been suggested that epicardial adipose tissue (EAT) plays an important role in development of coronary artery disease (CAD) and diabetes mellitus (DM). In this article, we used two-photon fluoresce microscope to measure the fluorescence metabolic image of EAT, which obtained from the patient with/without CAD/DM. We used 740nm and 890nm infrared light to excite the auto-fluorescence of metabolic molecules NADH and FAD respectively. We collected the fluorescence signal at wavelength 450nm to 500nm and 500nm to 550nm to obtain the metabolic image. Through the image, we computed the redox ratio (NADH/FAD) by analyzing the intensity. The preliminary result showed that the redox ratio increase in the patients with CAD. It indicates EAT adipocytes of patient with CAD have decreased cellular metabolic activity. But there were no significant variation of redox ratio in the patients with DM.

Q-005 SECRETION OF ADIPOKINES FROM EPICARDIAL, MEDIASTINAL, AND SUBCUTANEOUS ADIPOSE TISSUES IN HYPERTENSIVE PATIENTS WITH CORONARY ARTERY DISEASE

Subtitle Adipokines and hypertension Background Epicardial adipose tissue (EAT) shares a common embryological origin with intra-abdominal visceral fat depots and has been shown to be quantitatively related to various components of the metabolic syndrome, including hypertension. However, it is still not certain whether the secretions of adipokines from EAT and other fat depots differ between patients with and without hypertension. Methods Epicardial, mediastinal, and subcutaneous adipose tissues were collected from 36 patients with coronary artery disease underwent elective coronary artery bypass surgery. Levels of adiponectin, resistin, and leptin in adipose tissue-conditioned media were determined by ELISA. Hypertension was defined as patients being treated for hypertension or having a seated systolic blood pressure of ≥140 mm Hg or a diastolic blood pressure of ≥ 90 mm Hg. Results Overall, releases of adiponectin (∼2-fold), resistin (∼20-fold), and leptin (∼2-fold) were significantly higher in EAT than in subcutaneous adipose tissue, whereas only leptin release (∼2-fold) was increased in mediastinal than in subcutaneous adipose tissue. Compared to patients without hypertension (n = 10), hypertensive patients (n = 26) were associated with a significantly increased level of resistin (by 80%, p = 0.031) in subcutaneous adipose tissue-conditioned media. Despite no differences in levels of adipokines in EAT-conditioned media between patients with hypertension and those without, hypertensive patients had a significantly lower EAT/subcutaneous adipose tissue adiponectin ratio (1.9 ± 0.6 vs 3.8 ± 1.5, p = 0.014), after adjustments for age, gender, body-mass index, waist circumference, and conventional risk factors. Conclusions The co-existence of hypertension is associated with changes in adipokine secretions in both EAT and subcutaneous adipose tissue in patients with coronary artery disease. This finding provides a novel pathophysiologic link between hypertension and coronary artery disease.