Epicardial Adipose Tissue Thickness Is Related to Plaque Composition in Coronary Artery Disease.

(1) Background: Currently, limited data are available regarding the relationship between epicardial fat and plaque composition. The aim of this study was to assess the relationship between visceral fat surrounding the heart and the lipid core burden in patients with coronary artery diseases; (2) Methods: Overall, 331 patients undergoing coronary angiography with combined near-infrared spectroscopy and intravascular ultrasound imaging were evaluated for epicardial adipose tissue (EAT) thickness using transthoracic echocardiography. Patients were divided into thick EAT and thin EAT groups according to the median value; (3) Results: There was a positive correlation between EAT thickness and maxLCBI4mm, and maxLCBI4mm was significantly higher in the thick EAT group compared to the thin EAT group (437 vs. 293, p < 0.001). EAT thickness was an independent predictor of maxLCBI4mm ≥ 400 along with age, low-density lipoprotein-cholesterol level, acute coronary syndrome presentation, and plaque burden in a multiple linear regression model. Receiver operating characteristic curve analysis showed that EAT thickness was a predictor for maxLCBI4mm ≥ 400; (4) Conclusions: In the present study, EAT thickness is related to the lipid core burden assessed by NIRS-IVUS in patients with CAD which suggests that EAT may affect the stability of the plaques in coronary arteries.

Translesional Fractional Flow Reserve is Related to Plaque Components in Coronary Artery Disease: A Study Combining Pressure Wire and NIRS-IVUS Analysis.

OBJECTIVES: It remains unclear whether atherosclerotic plaque structure or composition is related to translesional biomechanical stresses in coronary artery disease. The aim of this study was to evaluate the association between translesional pressure parameters (using a pressure wire) and plaque characteristics (using a combined near-infrared spectroscopy [NIRS] and intravascular ultrasound [IVUS] imaging catheter). METHODS: Fractional flow reserve (FFR), delta (Δ) FFR, and Δ pressure were obtained during adenosine-induced maximum hyperemic status. Lipid core burden index (LCBI) and maximum LCBI within 2 mm (maxLCBI2mm) and tomographic anatomy were evaluated by NIRS-IVUS. RESULTS: Sixty-six lesions from 57 patients were analyzed (57 lesions for FFR, 45 lesions for ΔFFR). There was a negative correlation between FFR and maxLCBI2mm (r=-0.264; P=.049) and a positive correlation between ΔFFR and maxLCBI2mm (r=0.299; P=.049). ΔFFR of lesions with maxLCBI2mm ≥500 was significantly higher than maxLCBI2mm <500 (0.159 ± 0.085 vs 0.104 ± 0.075, respectively; P=.04). By receiver-operating characteristic curve analysis, ΔFFR ≥0.1 was a predictor for maxLCBI2mm ≥500 (area under curve, 0.707; 95% confidence interval, 0.552-0.862; P=.03). On multivariate analysis, ΔFFR was the only predictor of maxLCBI2mm (ß=0.347; P=.03). CONCLUSION: ΔFFR across a coronary artery lesion is related to lipid core burden assessed using NIRS-IVUS and might be a meaningful predictor of high-risk plaque (plaque with high lipid content).

Synthesis of arbutin-gold nanoparticle complexes and their enhanced performance for whitening.

Arbutin, a natural polyphenol, possesses numerous biological activities including whitening, anti-oxidant, anti-cancer, anti-inflammatory activities, as well as strong reducing power, making it an ideal bioactive ingredient for preparing gold nanoparticles (GNPs). Previously, we developed a novel green, mild synthetic method for GNPs using glycosides such as arbutin as reducing agents and stabilizers. Herein, we optimized the synthetic method for glycoside-GNPs using arbutin, methyl ß-D-glucoside, and phenyl ß-D-glucoside and validated their whitening efficacy in vitro and in vivo. The resulting glycoside-GNPs were predominantly mono-dispersed and spherical (10.30-17.13 nm diameter). Compared with arbutin itself, arbutin-GNP complexes (GNP-A1 and GNP-P2) displayed enhanced whitening capabilities. Furthermore, GNP-P2 exhibited enhanced anti-inflammatory activity and lacked the toxicity associated with arbutin. Bioactive glycoside-GNP complexes may open new directions for cosmeceuticals, and GNP-P2 may serve as a useful whitening ingredient in future cosmeceutical applications.

Free-space QKD system hacking by wavelength control using an external laser.

We develop a way to hack free-space quantum key distribution (QKD) systems by changing the wavelength of the quantum signal laser using an external laser. Most free-space QKD systems use four distinct lasers for each polarization, thereby making the characteristics of each laser indistinguishable. We also discover a side-channel that can distinguish the lasers by using an external laser. Our hacking scheme identifies the lasers by automatically applying the external laser to each signal laser at different intensities and detecting the wavelength variation according to the amount of incident external laser power. We conduct a proof-of-principle experiment to verify the proposed hacking structure and confirm that the wavelength varies by several gigahertzes to several nanometers, depending on the intensity of the external laser. The risk of hacking is successfully proven through the experimental results. Methods for prevention are also suggested.

Limits on manipulating conditional photon statistics via interference of weak lasers.

Photon anti-bunching, measured via the Hanbury-Brown-Twiss experiment, is one of the key signatures of quantum light and is tied to sub-Poissonian photon number statistics. Recently, it has been reported that photon anti-bunching or conditional sub-Poissonian photon number statistics can be obtained via second-order interference of mutually incoherent weak lasers and heralding based on photon counting [Phys. Rev. A92, 033855 (2015)10.1103/PhysRevA.92.033855; Opt. Express24, 19574 (2016)10.1364/OE.24.019574; https://arxiv.org/abs/1601.08161]. Here, we report theoretical analysis on the limits of manipulating conditional photon statistics via interference of weak lasers. It is shown that conditional photon number statistics can become super-Poissonian in such a scheme. We, however, demonstrate explicitly that it cannot become sub-Poissonian, i.e., photon anti-bunching cannot be obtained in such a scheme. We point out that incorrect results can be obtained if one does not properly account for seemingly negligible higher-order photon number expansions of the coherent state.

Evaluation of engraftment of superparamagnetic iron oxide-labeled mesenchymal stem cells using three-dimensional reconstruction of magnetic resonance imaging in photothrombotic cerebral infarction models of rats.

OBJECTIVE: To evaluate engraftment by visualizing the location of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) three-dimensionally in photothrombotic cerebral infarction (PTCI) models of rats. MATERIALS AND METHODS: Magnetic resonance imaging (MRI) of an agarose block containing superparamagnetic iron oxide (SPIO)-labeled hBM-MSCs was performed using a 3.0-T MRI, T2-(T2WI), T2(*)-(T2(*)WI), and susceptibility-weighted images (SWI). PTCI was induced in 6 rats, and 2.5 × 10(5) SPIO-labeled hBM-MSCs were infused through the ipsilateral internal carotid artery (ICA group) or tail vein (IV group). MRI was performed on days 1, 3, 7, and 14 after stem cell injection. Dark signal regions were confirmed using histology. Three-dimensional MRI reconstruction was performed using the clinical workflow solution to evaluate the engraftment of hBM-MSCs. Volumetric analysis of the engraftment was also performed. RESULTS: The volumes of SPIO-labeled hBM-MSCs in the phantom MRI were 129.3, 68.4, and 25.9 µL using SWI, T2(*)WI, and T2WI, respectively. SPIO-labeled hBM-MSCs appeared on day 1 after injection, encircling the cerebral infarction from the ventral side. Dark signal regions matched iron positive cells and human origin (positive) cells. The volume of the engraftment was larger in the ICA group on days 1, 3, and 7, after stem cell injection (p < 0.05 on SWI). SWI was the most sensitive MRI pulse sequence (p < 0.05). The volume of infarction decreased until day 14. CONCLUSION: The engraftment of SPIO-labeled hBM-MSCs can be visualized and evaluated three-dimensionally in PTCI models of rats. The engraftment volume was larger in the ICA group than IV group on early stage within one week.

Sensitivity of susceptibility-weighted imaging in detecting superparamagnetic iron oxide-labeled mesenchymal stem cells: a comparative study.

BACKGROUND: Susceptibility-weighted imaging (SWI) is extremely sensitive in the detection of superparamagnetic iron oxide (SPIO) nanoparticle-labeled cells. However, no study has compared molecular imaging for stem cell detection using SWI and other MRI pulse sequences. OBJECTIVES: This study aims to assess the sensitivity of SWI in detecting SPIO nanoparticle-labeled, human bone marrow-derived mesenchymal stem cells (SPIO-hMSCs) compared with that of T2- and T2*-weighted imaging (T2WI and T2*WI, respectively) in a phantom and in vivo study in rats. MATERIALS AND METHODS: A phantom was prepared with various cell concentrations. In one normal rat, SPIO-hMSCs were implanted directly through burr holes into both caudate putamens, while in three rats without and six rats with photothrombotic infarction, 2.5 × 10(5)/ml SPIO-hMSCs were infused into the ipsilateral internal carotid artery (ICA). T2WI, T2*WI, and SWI findings were compared for dark regions representing SPIO-hMSCs. RESULTS: SWI and T2*WI detected 15 µL of 13 SPIO-hMSCs/µL and 15 µL of 27 SPIO-hMSCs/µL in the phantom, respectively and 3 µL of 333 SPIO-hMSCs/µL and 3 µL of 167 SPIO-hMSCs/µL in the normal rat brain (direct implantation). In the normal rat brain (ICA infusion), one of the three cases showed numerous foci of dark regions dispersed throughout the brain on T2*WI and SWI. Dark regions surrounded the infarcts in all six infracted rat brains. The dark region was most prominent on SWI, followed by T2*WI and T2WI in all six rats (P = 0.002). Implanted SPIO-hMSCs were confirmed using Prussian blue staining. CONCLUSIONS: SWI is the most sensitive in the detection of SPIO-hMSCs, with the dark regions representing SPIO-hMSCs being more prominent on SWI than on T2*WI and T2WI.

Susceptibility-weighted imaging for stem cell visualization in a rat photothrombotic cerebral infarction model.

BACKGROUND: In cell therapy, magnetic resonance imaging (MRI) has been used to visualize superparamagnetic iron oxide (SPIO)-labeled stem cells homing to a lesion. Improving traceability is to utilize the sequence that maximizes sensitivity to the susceptibility effect of SPIO. PURPOSE: To explore the best method by comparing the MRI sequences to visualize mesenchymal stem cells (MSCs) labeled with SPIO. MATERIAL AND METHODS: Human bone marrow (hBM)-derived MSCs were labeled by internalization of SPIO nanoparticles. In vitro MRI was performed for the SPIO-labeled hBM-MSCs in tubes with T2-weighted (T2W), T2*-weighted (T2*W), and susceptibility-weighted images (SWI). Contrast-to-noise ratio (CNR) and volumes of dark signal of SPIO-labeled hBM-MSCs were obtained on images of each sequence. Photothrombotic cerebral infarction (PTCI) was induced in eight rats, and 2.5 × 10(5) SPIO-labeled hBM-MSCs were infused through the tail vein on the third day. In vivo MRI of the rat brain was performed using a 3.0 T MRI on the first, third, seventh, and 14th days. CNRspio was obtained on T2W imaging, T2*W imaging, and SWI. The dark signals were compared with the SPIO-positive cells of Prussian blue staining. RESULTS: In vitro MRI of 5 × 10(5) SPIO-labeled hBM-MSCs showed the CNR and volume of dark signal to be 63, 517 mm(3) in SWI, 41, 228 mm(3) in T2*W imaging, and 56, 41 mm(3) in T2W imaging, respectively. In vivo MRI showed a dark signal surrounding the high signal intensity of PTCI. Pathologically, the dark signals were matched with SPIO-labeled hBM-MSC in the corresponding rat. The dark signal was most prominent in SWI, then T2*W imaging, and finally in T2W imaging (P <0.05). In SWI, other causes of dark signals were matched with the veins and the choroid plexuses on histopathology. CONCLUSION: SWI can visualize SPIO-labeled hBM-MSCs more sensitively, earlier, and with larger size and greater contrast than T2W imaging and T2*W imaging.

Synthesis of gold nanoparticles with glycosides: synthetic trends based on the structures of glycones and aglycones.

A new, room temperature synthetic method for gold nanoparticles from auric acid with glycosides as reducing agents in aqueous NaOH is presented. As a mechanistic study of the oxidation sites on the glycosides, eight sugar-containing reductants (glycoside, glucose, glucuronic acid) have been tested in the synthesis of gold nanoparticles to determine their trends based on the structures of glycones and aglycones. As a result of the comparison among the eight sugar-containing reductants, it was determined that C-6 of glycosides is oxidized to a carboxylic acid during the reduction of auric acid. To detect the oxidized compounds of the glycosides, the reaction mixtures were monitored by (13)C NMR. Among the eight sugar-containing reductants, phenyl ß-D-glucoside generated the highest synthetic yield of mono-dispersed, round gold nanoparticles (13.15±1.30 nm, 99.7% yield).

Asymmetric synthesis and evaluation of α-quaternary chiral lactam derivatives as novel anticancer agents.

Asymmetric synthesis of α-quaternary chiral lactam derivatives as novel anticancer agents and evaluation of their cytotoxic potentials and spectrums are reported. Among the developed lactam derivatives, the most active new compounds (S)-4m and (S)-4n synthesized via asymmetric phase-transfer catalytic alkylation in very high optical yields (98 % ee) show promising in vitro anticancer activities with low micromolar IC50 values against colon, uterus, lung, and breast human cancer cells.

Engraftment of human mesenchymal stem cells in a rat photothrombotic cerebral infarction model : comparison of intra-arterial and intravenous infusion using MRI and histological analysis.

OBJECTIVE: This study aimed to evaluate the hypotheses that administration routes [intra-arterial (IA) vs. intravenous (IV)] affect the early stage migration of transplanted human bone marrow-derived mesenchymal stem cells (hBM-MSCs) in acute brain infarction. METHODS: Male Sprague-Dawley rats (n=40) were subjected to photothrombotic infarction. Three days after photothrombotic infarction, rats were randomly allocated to one of four experimental groups [IA group : n=12, IV group : n=12, superparamagnetic iron oxide (SPIO) group : n=8, control group : n=8]. All groups were subdivided into 1, 6, 24, and 48 hours groups according to time point of sacrifice. Magnetic resonance imaging (MRI) consisting of T2 weighted image (T2WI), T2(*) weighted image (T2(*)WI), susceptibility weighted image (SWI), and diffusion weighted image of rat brain were obtained prior to and at 1, 6, 24, and 48 hours post-implantation. After final MRI, rats were sacrificed and grafted cells were analyzed in brain and lung specimen using Prussian blue and immunohistochemical staining. RESULTS: Grafted cells appeared as dark signal intensity regions at the peri-lesional zone. In IA group, dark signals in peri-lesional zone were more prominent compared with IV group. SWI showed largest dark signal followed by T2(*)WI and T2WI in both IA and IV groups. On Prussian blue staining, IA administration showed substantially increased migration and a large number of transplanted hBM-MSCs in the target brain than IV administration. The Prussian blue-positive cells were not detected in SPIO and control groups. CONCLUSION: In a rat photothrombotic model of ischemic stroke, selective IA administration of human mesenchymal stem cells is more effective than IV administration. MRI and histological analyses revealed the time course of cell migration, and the numbers and distribution of hBM-MSCs delivered into the brain.

Design of deformable chitosan microspheres loaded with superparamagnetic iron oxide nanoparticles for embolotherapy detectable by magnetic resonance imaging.

The purpose of this study was to design chitosan microspheres (MS) loaded with superparamagnetic iron oxide nanoparticles (SPIO) suitable for anti-cancer embolotherapy detectable by MRI. Deformable chitosan MS loaded with varying SPIO concentrations (SPIO-chitosan MS) were prepared by ionotropic gelation and a porogenic technique using polyethylene glycol, followed by genipin crosslinking. Adding SPIO nanoparticles to chitosan MS did not significantly affect the chitosan MS morphology. An in vitro phantom study led to selecting SPIO-chitosan MS prepared with 1.0 mM SPIO for an in vivo MR traceability study. SPIO-chitosan MS could be identified following embolization in the renal artery by MRI at 18 weeks. Histological and pathological evidence also showed that SPIO-chitosan MS blocked and remained in the target vessels. Therefore, deformable SPIO-chitosan MS is MR-detectable embolic material with a possible application for anti-cancer embolotherapy.