[Histological and ultrastructural features of giant cell myocarditis: report of 3 cases].

OBJECTIVE:To identify clinical and pathological features of giant cell myocarditis.METHODS:Clinical presentation and follow-up data of three patients with giant cell myocarditis were collected.Gross, histopathological, immunohistological and ultrastructural findings of extransplantated hearts of the patients were documented.RESULTS:Grossly, multifocal involvement of the myocardium with variably dilated cardiac chambers were observed in all 3 cases.Histological examination revealed pronounced focal inflammatory infiltrates with multinucleated giant cells. Multinucleated giant cells were positive for CD68 and CD11b immunostains but were negative for CD163 in all cases. Transmission electron microscopy showed that the multinucleated giant cells derived from fusion of several macrophages with adherent lymphocytes and secretary cells. Clinically, the overall patient condition improved in all three cases after heart transplantation.One patient experienced acute cellular rejection (2R level) 4 months after transplantation, but recovered after treatment. One patient developed multinucleated giant cells observed in heart biopsy two weeks after transplantation.CONCLUSIONS:Giant-cell myocarditis is a rare disease of adult, and cardiac transplantation could improve the clinical outcome. Multinucleated giant cell in the myocarditis lesions were derived from macrophages, likely participating in the immune response. Endomyocardial biopsy is important for the diagnosis of giant cell myocarditis.

[Association between clinical features and histopathological findings in patients with left ventricular non-compaction cardiomyopathy].

OBJECTIVE:To investigate the association between clinical and histopathological features in patients with left ventricular non-compaction cardiomyopathy (LVNC).METHODS:Histopathological examinations were made on 11 LVNC recipient hearts from June 2004 to June 2014 in Fuwai Hospital, myocardial ultrastructure changes were detected using transmission electron microscopy. Association between clinical and pathological features were analyzed.RESULTS:Patients were (24 ± 11) years old. There were 6 patients with mucus matrix LVNC, 3 patients with fibrous fatty infiltration, and 2 patients with cardiomyocytes proliferation. The gross morphological changes of LVNC hearts were characterized by numerous and prominent trabeculations with deep intratrabecular recesses in left ventricular myocardium. Ratios of the thicker noncompacted endocardial layer (N) and thin epicardial compacted layer (C) (N/C ratio) were ≥ 2.0, and the most serious lesions were located in the left ventricular apex, and followed by the left ventricular free wall. Histological microscopic examinations evidenced numerous matrix-like material and immature cardiomyocytes on endocardial tissue. Transmission electron microscopy revealed mitochondrial abnormalities on morphology, number, and distribution, underdeveloped cardiomyocytes and anomalies of intercalated disc structure, increased deposition of extracellular matrix-like substance and perinuclear glycogen. Pathological changes on cytoplasmic matrix and intercalated disc were present in all three tissue types of LVNC in this cohort and mitochondria hyperplasia was detected in patients with fibrous fatty infiltration. Heart weight ≥ 350 g is often associated with increased number of mitochondria. Increased cytoplasmic matrix was often detected in patients with LVEF ≥ 30% while intercalated disc anomalies were often detected in patients with LVEF < 30%.CONCLUSION:Histological changes were closely related clinical features in patients with LVNC.

[Myocardial changes in heart transplantation recipients with primary restrictive cardiomyopathy].

OBJECTIVE:To investigate the histopathological features of primary restrictive cardiomyopathy (PRCM).METHODS:Nine extransplanted hearts from heart transplantation recipients were examined. Gross and histopathological findings were observed, photographed and final pathological diagnosis was compared to clinical diagnosis. The myocardial ultrastructure changes were determined using transmission electron microscopy.RESULTS:The hallmark pathologic feature of PRCM was distinguished by myocardial cell degeneration and hyperplastic collagen fibrils around the myocardial cells.Fibrosis was severer in left ventricle free wall than in ventricular septum and right ventricle. The degree of myocardial cell degeneration and poloidal disorder were severer in patients with reduced ejection fraction (EF) than in patients with preserved EF. Transmission electron microscope evidenced severe interstitial fibrosis, myofibrillar changes of sarcomere structure, abnormalities both on intercalated disc number and distribution.CONCLUSIONS:PRCM is characterized by hyperplastic collagen fibrils around the cardiomyocytes. Fibrosis is severer in left ventricle than in right ventricle. Sarcomere dysplasia is the main cause of PRCM, and ultrastructural examination is helpful for PRCM diagnosis.

Short-term safety and effects of a novel fully bioabsorable poly-L-lactic acid sirolimus-eluting stents in porcine coronary arteries.

Short-term safety and efficacy of the biodegradable iron stent in mini-swine coronary arteries.

BACKGROUND: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.METHODS: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.RESULTS: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.CONCLUSIONS: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.

[Relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model].

OBJECTIVE:To study the relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model.METHODS: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.RESULTS: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).CONCLUSION:Inflammation promotes the neointimal proliferation after coronary stent implantation. Sirolimus-eluting stent may reduce the inflammatory response.

[Comparative study on the ultrastructures of radial and internal mammary arteries used for coronary artery bypass grafting].

OBJECTIVE: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.METHODS: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.RESULTS: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.CONCLUSIONS: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.

Effects of Salvia miltiorrhiza extracts on rat hypoxic pulmonary hypertension, heme oxygenase-1 and nitric oxide synthase.

OBJECTIVE:To investigate the effects of Salvia miltiorrhiza (SM) extracts on the expression of heme oxygenase-1 (HO-1) and nitric oxide synthase (NOS) in small pulmonary arteries (SPAs) of rats with chronic hypoxia.METHODS:After two weeks of hypoxia, rats were treated with diltiazem, and small, median, and large doses of SM extracts. The lungs were tested for the expression and distribution of HO-1, endothelial NOS (eNOS) and inducible NOS (iNOS) by using immunohistochemistry and Western blot method.RESULTS:Median and large doses of SM extracts significantly reduced hypoxia-induced media thickening in the SPAs (similar with diltiazem), recovered repaired ultrastructure injury, decreased HO-1 and iNOS levels, and increased eNOS expression in the SPAs.CONCLUSIONS:Median and large doses of SM extracts play significant roles in inhibiting structural remodeling in rats with hypoxic pulmonary hypertension. These effects might attribute to the suppression of HO-1 and iNOS, and the promotion of eNOS expression under the conditions of hypoxia.

[The role of transforming growth factor-beta(1) in smoking-induced chronic bronchitis and emphysema in hamsters].

OBJECTIVE:To study the role of transforming growth factor-beta(1) (TGF-beta(1)) in the pathogenesis of chronic bronchitis and emphysema.METHODS:An animal model of chronic bronchitis and emphysema was developed in hamsters by chronic smoke inhalation. The expression of TGF-beta(1) mRNA and protein in the pulmonary tissue was observed. The bronchial epithelia was stimulated with cigarette smoke extract (CSE) in vitro and the expression of TGF-beta(1) was measured.RESULTS:3 months after smoking, the animals developed chronic bronchitis and emphysema. TGF-beta(1) immunoreactivity in the pulmonary tissue and cultured bronchial epithelia increased significantly as compared to the normal control (2.75 +/- 0.23 vs 0.84 +/- 0.39, P = 0.001 and 2.67 +/- 0.16 vs 0.85 +/- 0.54, P = 0.001). The expression of TGF-beta(1) mRNA was also increased in the animal model (1.28 vs 0.98).CONCLUSIONS:Smoking can induce over-expression of TGF-beta(1) in bronchial epithelia, which may be one of the mechanisms for smoking-induced chronic bronchitis and emphysema.

[Histological and ultrastructural features of giant cell myocarditis: report of 3 cases].

OBJECTIVE:To identify clinical and pathological features of giant cell myocarditis.METHODS:Clinical presentation and follow-up data of three patients with giant cell myocarditis were collected.Gross, histopathological, immunohistological and ultrastructural findings of extransplantated hearts of the patients were documented.RESULTS:Grossly, multifocal involvement of the myocardium with variably dilated cardiac chambers were observed in all 3 cases.Histological examination revealed pronounced focal inflammatory infiltrates with multinucleated giant cells. Multinucleated giant cells were positive for CD68 and CD11b immunostains but were negative for CD163 in all cases. Transmission electron microscopy showed that the multinucleated giant cells derived from fusion of several macrophages with adherent lymphocytes and secretary cells. Clinically, the overall patient condition improved in all three cases after heart transplantation.One patient experienced acute cellular rejection (2R level) 4 months after transplantation, but recovered after treatment. One patient developed multinucleated giant cells observed in heart biopsy two weeks after transplantation.CONCLUSIONS:Giant-cell myocarditis is a rare disease of adult, and cardiac transplantation could improve the clinical outcome. Multinucleated giant cell in the myocarditis lesions were derived from macrophages, likely participating in the immune response. Endomyocardial biopsy is important for the diagnosis of giant cell myocarditis.

[Association between clinical features and histopathological findings in patients with left ventricular non-compaction cardiomyopathy].

OBJECTIVE:To investigate the association between clinical and histopathological features in patients with left ventricular non-compaction cardiomyopathy (LVNC).METHODS:Histopathological examinations were made on 11 LVNC recipient hearts from June 2004 to June 2014 in Fuwai Hospital, myocardial ultrastructure changes were detected using transmission electron microscopy. Association between clinical and pathological features were analyzed.RESULTS:Patients were (24 ± 11) years old. There were 6 patients with mucus matrix LVNC, 3 patients with fibrous fatty infiltration, and 2 patients with cardiomyocytes proliferation. The gross morphological changes of LVNC hearts were characterized by numerous and prominent trabeculations with deep intratrabecular recesses in left ventricular myocardium. Ratios of the thicker noncompacted endocardial layer (N) and thin epicardial compacted layer (C) (N/C ratio) were ≥ 2.0, and the most serious lesions were located in the left ventricular apex, and followed by the left ventricular free wall. Histological microscopic examinations evidenced numerous matrix-like material and immature cardiomyocytes on endocardial tissue. Transmission electron microscopy revealed mitochondrial abnormalities on morphology, number, and distribution, underdeveloped cardiomyocytes and anomalies of intercalated disc structure, increased deposition of extracellular matrix-like substance and perinuclear glycogen. Pathological changes on cytoplasmic matrix and intercalated disc were present in all three tissue types of LVNC in this cohort and mitochondria hyperplasia was detected in patients with fibrous fatty infiltration. Heart weight ≥ 350 g is often associated with increased number of mitochondria. Increased cytoplasmic matrix was often detected in patients with LVEF ≥ 30% while intercalated disc anomalies were often detected in patients with LVEF < 30%.CONCLUSION:Histological changes were closely related clinical features in patients with LVNC.

[Myocardial changes in heart transplantation recipients with primary restrictive cardiomyopathy].

OBJECTIVE:To investigate the histopathological features of primary restrictive cardiomyopathy (PRCM).METHODS:Nine extransplanted hearts from heart transplantation recipients were examined. Gross and histopathological findings were observed, photographed and final pathological diagnosis was compared to clinical diagnosis. The myocardial ultrastructure changes were determined using transmission electron microscopy.RESULTS:The hallmark pathologic feature of PRCM was distinguished by myocardial cell degeneration and hyperplastic collagen fibrils around the myocardial cells.Fibrosis was severer in left ventricle free wall than in ventricular septum and right ventricle. The degree of myocardial cell degeneration and poloidal disorder were severer in patients with reduced ejection fraction (EF) than in patients with preserved EF. Transmission electron microscope evidenced severe interstitial fibrosis, myofibrillar changes of sarcomere structure, abnormalities both on intercalated disc number and distribution.CONCLUSIONS:PRCM is characterized by hyperplastic collagen fibrils around the cardiomyocytes. Fibrosis is severer in left ventricle than in right ventricle. Sarcomere dysplasia is the main cause of PRCM, and ultrastructural examination is helpful for PRCM diagnosis.

Short-term safety and effects of a novel fully bioabsorable poly-L-lactic acid sirolimus-eluting stents in porcine coronary arteries.

Short-term safety and efficacy of the biodegradable iron stent in mini-swine coronary arteries.

BACKGROUND: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.METHODS: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.RESULTS: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.CONCLUSIONS: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.

[Relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model].

OBJECTIVE:To study the relationship between inflammation and neointimal proliferation after coronary stent implantation in porcine model.METHODS: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.RESULTS: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).CONCLUSION:Inflammation promotes the neointimal proliferation after coronary stent implantation. Sirolimus-eluting stent may reduce the inflammatory response.

[Comparative study on the ultrastructures of radial and internal mammary arteries used for coronary artery bypass grafting].

OBJECTIVE: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.METHODS: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.RESULTS: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.CONCLUSIONS: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.

Effects of Salvia miltiorrhiza extracts on rat hypoxic pulmonary hypertension, heme oxygenase-1 and nitric oxide synthase.

OBJECTIVE:To investigate the effects of Salvia miltiorrhiza (SM) extracts on the expression of heme oxygenase-1 (HO-1) and nitric oxide synthase (NOS) in small pulmonary arteries (SPAs) of rats with chronic hypoxia.METHODS:After two weeks of hypoxia, rats were treated with diltiazem, and small, median, and large doses of SM extracts. The lungs were tested for the expression and distribution of HO-1, endothelial NOS (eNOS) and inducible NOS (iNOS) by using immunohistochemistry and Western blot method.RESULTS:Median and large doses of SM extracts significantly reduced hypoxia-induced media thickening in the SPAs (similar with diltiazem), recovered repaired ultrastructure injury, decreased HO-1 and iNOS levels, and increased eNOS expression in the SPAs.CONCLUSIONS:Median and large doses of SM extracts play significant roles in inhibiting structural remodeling in rats with hypoxic pulmonary hypertension. These effects might attribute to the suppression of HO-1 and iNOS, and the promotion of eNOS expression under the conditions of hypoxia.

[The role of transforming growth factor-beta(1) in smoking-induced chronic bronchitis and emphysema in hamsters].

OBJECTIVE:To study the role of transforming growth factor-beta(1) (TGF-beta(1)) in the pathogenesis of chronic bronchitis and emphysema.METHODS:An animal model of chronic bronchitis and emphysema was developed in hamsters by chronic smoke inhalation. The expression of TGF-beta(1) mRNA and protein in the pulmonary tissue was observed. The bronchial epithelia was stimulated with cigarette smoke extract (CSE) in vitro and the expression of TGF-beta(1) was measured.RESULTS:3 months after smoking, the animals developed chronic bronchitis and emphysema. TGF-beta(1) immunoreactivity in the pulmonary tissue and cultured bronchial epithelia increased significantly as compared to the normal control (2.75 +/- 0.23 vs 0.84 +/- 0.39, P = 0.001 and 2.67 +/- 0.16 vs 0.85 +/- 0.54, P = 0.001). The expression of TGF-beta(1) mRNA was also increased in the animal model (1.28 vs 0.98).CONCLUSIONS:Smoking can induce over-expression of TGF-beta(1) in bronchial epithelia, which may be one of the mechanisms for smoking-induced chronic bronchitis and emphysema.