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Objectives: The aim of this study was to investigate the influence of microvascular damage in one vessel territory on invasively measured physiological parameters in the other vessel, using a porcine microvascular damage model., Background: Although fractional flow reserve (FFR)-guided decision-making for the nonculprit stenosis in patients with acute myocardial infarction has been reported to be better than angiography-guided revascularization, there have been debates regarding the influence of microvascular dysfunction on measured FFR in nonculprit vessels., Methods: In Yorkshire swine, microvascular damage was induced with selective intracoronary injection of microspheres (100 μm × 10 5 each) into the left anterior descending artery (LAD). Coronary stenosis was created in both the LAD and the left circumflex artery (LCx) using balloon catheters. Coronary physiological changes were assessed with index of microcirculatory resistance (IMR) and FFR at baseline and at each subsequent injection of microsphere up to a fifth dose in both the LAD and LCx. Measurements were repeated 5 times at each stage, and a total of 424 measurements were made in 12 Yorkshire swine models., Results: The median area stenosis in LAD and LCx was 48.1% (interquartile range: 40.8% to 50.4%) and 47.9% (interquartile range: 31.1% to 62.9%), respectively. At baseline, FFR in the LAD was lower than that in the LCx (0.89 ± 0.01 and 0.94 ± 0.01; p < 0.001). There was no difference in the IMR (18.4 ± 5.8 U and 17.9 ± 1.2 U; p = 0.847). With repeated injections of microspheres, IMR in LAD was significantly increased, up to 77.7 ± 15.7 U (p < 0.001). Given the same stenosis, FFR in the LAD was also significantly increased, up to 0.98 ± 0.01 along with IMR increase (p < 0.001). Conversely, IMR and FFR were not changed in the LCx throughout repeated injury to the LAD territory (p = 0.105 and p = 0.286 for IMR and FFR, respectively). The increase in LAD IMR was mainly driven by the increase in hyperemic mean transit time (p < 0.001)., Conclusions: In Yorkshire swine models, local microvascular damage increased both FFR and IMR in a vessel supplying target myocardial territory. However, IMR and FFR were maintained in the other vessel. These physiological results in swine support the concept that FFR measurement might provide useful information for evaluating nonculprit lesions in clinical settings involving significant acute myocardial injury., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Nontuberculous mycobacteria (NTM) have been increasingly recognized as an important cause of chronic pulmonary infections. The Mycobacterium avium complex (MAC), which is composed of two species, Mycobacterium avium and Mycobacterium intracelluare, is the most commonly encountered pathogen associated with NTM lung disease. MAC pulmonary infection typically presents in a fibrocavitary form or a nodular bronchiectatic form. However, there have been atypical presentations of MAC pulmonary infections, including solitary pulmonary nodules (SPN). There have been several previous reports of SPN due to MAC infection in the United States, Japan, and Korea. In 2009, Sekine and colleagues reported a case of MAC pulmonary infection presenting with multiple nodules. To date, however, there have been no cases of NTM lung infection with multiple cavitary pulmonary nodules, and neither a fibrotic change nor nodular bronchiectasis. The present case showed a multiple cavitating nodular lung infection due to MAC, which is very rare and different from the typical presentation of MAC pulmonary infections. We also showed that percutaneous transthoracic needle aspiration can be a useful diagnostic tool to evaluate a case of multiple cavitary nodules.

The aim of this study was to evaluate antiproliferative sirolimus- and antioxidative alpha-lipoic acid (ALA)-eluting stents using biodegradable polymer [poly-L-lactic acid (PLA)] in a porcine coronary overstretch restenosis model. Forty coronary arteries of 20 pigs were randomized into four groups in which the coronary arteries had a bare metal stent (BMS, n = 10), ALA-eluting stent with PLA (AES, n = 10), sirolimus-eluting stent with PLA (SES, n = 10), or sirolimus- and ALA-eluting stent with PLA (SAS, n = 10). A histopathological analysis was performed 28 days after the stenting. The ALA and sirolimus released slowly over 30 days. There were no significant differences between groups in the injury or inflammation score; however, there were significant differences in the percent area of stenosis (56.2 ± 11.78% in BMS vs. 51.5 ± 12.20% in AES vs. 34.7 ± 7.23% in SES vs. 28.7 ± 7.30% in SAS, P < 0.0001) and fibrin score [1.0 (range 1.0-1.0) in BMS vs. 1.0 (range 1.0-1.0) in AES vs. 2.0 (range 2.0-2.0) in SES vs. 2.0 (range 2.0-2.0) in SAS, P < 0.0001] between the four groups. The percent area of stenosis based on micro-computed tomography corresponded with the restenosis rates based on histopathological stenosis in different proportions in the four groups (54.8 ± 7.88% in BMS vs. 50.4 ± 14.87% in AES vs. 34.5 ± 7.22% in SES vs. 28.9 ± 7.22% in SAS, P < 0.05). SAS showed a better neointimal inhibitory effect than BMS, AES, and SES at 1 month after stenting in a porcine coronary restenosis model. Therefore, SAS with PLA can be a useful drug combination for coronary stent coating to suppress neointimal hyperplasia.

In this study, we aimed to evaluate the mechanical effects of different stent linker designs on in-stent restenosis in porcine coronary arteries. We fabricated stents with an open-cell structure composed of nine main cells and three linker structures in model 1 (I-type), model 2 (S-types) and model 3 (U-types)) as well as Model 4, which is similar to a commercial bare metal stent design. The stent cells were 70 mm thick and wide, with a common symmetrical wave pattern. As the radial force increased, the number of main cells increased and the length of linker decreased. Radial force was higher in model 1, with a linear I-linker, than in models with S- or U-linkers. The flexibility measured by three-point bending showed a force of 1.09 N in model 1, 0.35 N in model 2, 0.19 N in model 3, and 0.31 N in model 4. The recoil results were similar in all models except model 4 and were related to the shape of the main cells. The foreshortening results were related to linker shape, with the lowest foreshortening observed in model 3 (U-linker). Restenosis areas in the porcine restenosis model 4 weeks after implantation were 35.4 ± 8.39% (model 1), 30.4 ± 7.56% (model 2), 40.6 ± 9.87% (model 3) and 45.1 ± 12.33% (model 4). In-stent restenosis rates measured by intravascular ultrasound (IVUS) and micro-computed tomography (micro-CT) showed similar trends as percent area stenosis measured by micro-CT. Model 2, with optimized flexibility and radial force due to its S-linker, showed significantly reduced restenosis in the animal model compared to stents with different linker designs. These results suggest that the optimal stent structure has a minimum radial force for vascular support and maximum flexibility for vascular conformability. The importance of the effects of these differences in stent design and their potential relationship with restenosis remains to be determined., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The drug-eluting stent still has limitations such as thrombosis and inflammation. These limitations often occur in the absence of endothelialization. This study investigated the effects of WKYMVm- and sirolimus-coated stents on re-endothelialization and anti-restenosis. The WKYMVm peptide, specially synthesized for homing endothelial colony-forming cells, was coated onto a bare-metal stent with hyaluronic acid through a simple dip-coating method (designated HA-Pep). Thereafter, sirolimus was consecutively coated to onto the HA-Pep (designated Pep/SRL). The cellular response to stents by human umbilical-vein endothelial cells and vascular smooth-muscle cells was examined by XTT assay. Stents were implanted into rabbit iliac arteries, isolated 6 weeks post-implantation, and then subjected to histological analysis. The peptide was well attached to the surface of the stents and the sirolimus coating made the surface smooth. The release pattern for sirolimus was similar to that of commercial sirolimus-coated stents (57.2% within 7 days, with further release for up to 28 days). Endothelial-cell proliferation was enhanced in the HA-Pep group after 7 days of culture (38.2 ± 7.62%, compared with controls). On the other hand, the proliferation of smooth-muscle cells was inhibited in the Pep/SRL group after 7 days of culture (40.7 ± 6.71%, compared with controls). In an animal study, the restenosis rates for the Pep/SRL group (13.5 ± 4.50%) and commercial drug-eluting stents (Xience Prime™; 9.2 ± 7.20%) were lower than those for bare-metal stents (25.2 ± 4.52%) and HA-Pep stents (26.9 ± 3.88%). CD31 staining was incomplete for the bare-metal and Xience Prime™ groups. On the other hand, CD31 staining showed a consecutive linear pattern in the HA-Pep and Pep/SRL groups, suggesting that WKYMVm promotes endothelialization. These results indicate that the WKYMVm coating could promote endothelial healing, and consecutive coatings of WKYMVm and sirolimus onto bare-metal stents have a potential role in re-endothelialization and neointimal suppression.

Unlabelled: CuraVAC Ag, a product that delivers negative pressure wound therapy through a polyurethane foam dressing, contains silver nanoparticles, which, when moistened with water, release silver ions onto a wound surface. The in vitro antimicrobial action of silver can destroy both gram-positive and gram-negative bacteria, as well as methicillin-resistant Staphylococcus aureus (MRSA). The purpose of this study was to assess the efficacy and in vivo outcomes of using the product., Methods: Thirty-six female Sprague-Dawley white rats, 8-weeks old and 250 g - 300 g in weight, were used. The experimental product was prepared using a vacuum-assisted closure (VAC) kit and coating it using the silver nanoparticles. For the control group, a 10% povidone-iodine solution was applied., Results: All groups showed decreases in wound area over time, in the order CuraVAC Ag (group A) > CuraVAC (group B) > control (group C). On the third, fifth, and seventh days, wound healing efficacy scores increased in both group A and group C. Groups A and B showed more rapid decreases than group C in bacterial culture from wounds., Conclusion: CuraVAC Ag may be useful for treatment of wounds infected with bacteria..