Short-term safety and efficacy of the biodegradable iron stent in mini-swine coronary arteries / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>To overcome the drawbacks of permanent stents, biodegradable stents have been studied in recent years. The bioabsorbable polymer vascular scaffold (BVS) was the first bioabsorbable stent to undergo clinical trials, demonstrating safety and feasibility in the ABSORB studies. Iron can potentially serve as the biomaterial for biodegradable stents. This study aimed to assess the short-term safety and efficacy of a biodegradable iron stent in mini-swine coronary arteries.</p><p><b>METHODS</b>Eight iron stents and eight cobalt chromium alloy (VISION) control stents were randomly implanted into the LAD and RCA of eight healthy mini-swine, respectively. Two stents of the same metal base were implanted into one animal. At 28 days the animals were sacrificed after coronary angiography, and histopathological examinations were performed.</p><p><b>RESULTS</b>Histomorphometric measurements showed that mean neointimal thickness ((0.46 ± 0.17) mm vs. (0.45 ± 0.18) mm, P = 0.878), neointimal area ((2.55 ± 0.91) mm(2) vs. (3.04 ± 1.15) mm(2), P = 0.360) and percentage of area stenosis ((44.50 ± 11.40)% vs. (46.00 ± 17.95)%, P = 0.845) were not significantly different between the iron stents and VISION stents. There was no inflammation, thrombosis or necrosis in either group. The scanning electron microscopy (SEM) intimal injury scores (0.75 ± 1.04 vs. 0.88 ± 0.99, P = 0.809) and number of proliferating cell nuclear antigen (PCNA) positive staining cells were not significantly different between the two groups. The percentage of neointimal coverage by SEM examination was numerically higher in iron stents than in VISION stents ((84.38 ± 14.50)% vs. (65.00 ± 22.04)%, P = 0.057), but the difference was not statistically significant. Iron staining in the tissue surrounding the iron stents at 28 days was positive and the vascular wall adjacent to the iron stent had a brownish tinge, consistent with iron degradation. No abnormal histopathological changes were detected in coronary arteries or major organs.</p><p><b>CONCLUSIONS</b>The biodegradable iron stent has good biocompatibility and short-term safety and efficacy in the miniswine coronary artery. Corrosion of iron stents is observed at four weeks and no signs of organ toxicity related to iron degradation were noted.</p>

Role of aerodynamic parameters in voice function assessment / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the application and significance of aerodynamic parameters in voice function assessment.</p><p><b>METHODS</b>The phonatory aerodynamic system (PAS) was used to collect aerodynamic parameters from subjects with normal voice, vocal fold polyp, vocal fold cyst, and vocal fold immobility. Multivariate statistical analysis was used to compare measurements across groups.</p><p><b>RESULTS</b>Phonation threshold flow (PTF), mean flow rate (MFR), maximum phonation time (MPT), and glottal resistance (GR) in one hundred normal subjects were significantly affected by sex (P < 0.05), while phonation threshold pressure (PTP), subglottal pressure (SGP), and vocal efficiency (VE) were not (P > 0.05). PTP, PTF, MFR, SGP, and MPT were significantly different between normal voice and voice disorders (P < 0.01), and there were no significant differences among the three disorders (P > 0.05). Receiver operating characteristic (ROC) analysis found that PTP, PTF, SGP, MFR, MPT, and VE in one hundred thirteen voice dis orders had similar diagnostic utility (P < 0.01), with PTP exhibiting the highest area under the curve. The aerodynamic parameters of the three degrees of voice dysfunction due to vocal cord polyps were compared and found to have no significant differences (P > 0.05). PTP, PTF, MFR, SGP and MPT in forty one patients with vocal polyps were significantly different after surgical resection of vocal cord polyps (P < 0.01).</p><p><b>CONCLUSION</b>The aerodynamic parameters can objectively and effectively evaluate the variations of vocal function, and have good auxiliary diagnostic value.</p>

Relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model.</p><p><b>METHODS</b>Twenty normal minipigs were randomly divided into group A (implanted with 316L bare metal stents), group B (implanted with 605L bare metal stents), group C (implanted with PLGA coating 605L stents), and group D (implanted with rapamycin-loaded PLGA coating 605L stents). Each minipig was implanted with two same stents in left anterior descending artery and right coronary artery. Four weeks later, the animals were sacrificed and histomorphometric measurements on the stent-segment coronary arteries were made to calculate the correlation between inflammation area and neointimal area.</p><p><b>RESULTS</b>Group D had the smallest neointimal area [(0.64 +/- 0.38) mm2, P < 0. 001] and inflammation area (median 0.00 mm2, P = 0.009) among all the groups, while there were no statistical differences among group A, B, and C in neointimal area [(2.09 +/- 0.90), (2.11 +/- 1.07), and (1.42 +/- 0.35) mm2 respectively] and in inflammation area (0.22 , 0.21, and 0.09 mm2, respectively). Bivariate correlation analysis showed that the inflammation area was positively correlated with the neointimal area (P < 0.001, correlation coefficient = 0.719). When stent type, mean injury score, and EEL area were adjusted, partial correlations analysis showed that the inflammation area was still positively correlated with the neointimal area (P = 0.01, correlation coefficient = 0.498).</p><p><b>CONCLUSION</b>Inflammation promotes the neointimal proliferation after coronary stent implantation. Sirolimus-eluting stent may reduce the inflammatory response.</p>

Comparative study on the ultrastructures of radial and internal mammary arteries used for coronary artery bypass grafting / 中华病理学杂志

<p><b>OBJECTIVE</b>The radial artery differs from internal mammary artery in its vascular biology and long-term patency after coronary artery bypass grafting (CABG). This study was designed to investigate their ultrastructural differences that may have implications in arterial remodeling and graft failure.</p><p><b>METHODS</b>Thirty-four radial artery and 11 internal mammary artery samples were obtained from patients underwent CABG, and subjected to routine electron microscopic examination. A semi-quantitative method was used to evaluate secretary endothelial cells, endothelial denudation, synthetic smooth muscle cells (SMCs), matrix accumulation, lipid deposition and medial submicroscopic calcification.</p><p><b>RESULTS</b>Compared with internal mammary arteries, the radial arteries had more secretory endothelial cells (47.1%, 16/34 vs 27.2%, 3/ 11) and synthetic type SMCs in a background (14.4% vs 0.9%) that had more intimal lipid deposition and matrix accumulation (14.7%, 5/34 vs 9.1%, 1/11). Matrix vesicles and calcifications were frequently present in the media of both types of arteries. The calcifications, however, could not be visualized by routine histological stains, and therefore, named as submicroscopic calcification in this study. Fewer endothelial denudations were observed in the radial arteries, but no differences in medial lipid deposition and submicroscopic calcification were observed between these two types of arteries. The ultrastructural features and the arrangement of medial SMCs in radial arteries were similar to those of internal mammary arteries.</p><p><b>CONCLUSIONS</b>Radial arteries have a higher SMC proliferative potential and more actively secretory status of endothelial cells, which may enhance the remodeling process and correlate with a decreased long-term patency. Better preservation of endothelial cells in radial arteries could be attributed to the "no touch" technique utilized in surgical harvesting. The significance of submicroscopic medial calcification during graft remodeling requires further investigations.</p>