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Biomedical subjects

Hatsue Ishibashi-Ueda

Publications and source records attributed to Hatsue Ishibashi-Ueda.

At least 19 recordsLinked to original sources
PubMed2006

Transplantation of mesenchymal stem cells attenuates myocardial injury and dysfunction in a rat model of acute myocarditis.

Acute myocarditis is a non-ischemic inflammatory disease of the myocardium for which there is currently no specific treatment. We have previously shown that mesenchymal stem cells (MSC) can ameliorate heart injury during acute ischemia and in dilated cardiomyopathy; however, the therapeutic potential in acute myocarditis is unclear. In this study, we investigated the ability of MSC to attenuate myocardial injury and dysfunction during the acute phase of experimental myocarditis. Ten-week-old male Lewis rats were injected with porcine myosin to induce myocarditis. Cultured MSC (3x10(6) cells/rat) were injected intravenously 7 days after myosin injection. At 3 weeks, myosin injection resulted in severe inflammation and significant deterioration of cardiac function. MSC transplantation attenuated increases in CD68-positive inflammatory cells and monocyte chemoattractant protein-1 (MCP-1) expression in myocardium, and improved cardiac function in this model. Furthermore, myocardial capillary density was higher in myocarditis tissue, and was further increased by MSC transplantation. In vitro, cultured adult rat cardiomyocytes were injured in response to MCP-1, whereas this effect was attenuated by MSC-derived conditioned medium, suggesting cardioprotective effects of MSC acting in a paracrine manner. MSC transplantation attenuated myocardial injury and dysfunction in a rat model of acute myocarditis, at least in part through paracrine effects of MSC.

Acute Disease↗
PubMed2006

Immunohistological findings for an extracardiac conduit in Fontan pathway constructed with pedicled autologous pericardium.

Although autologous pericardium has been used in pedicled fashion for various reconstructive procedures in congenital cardiovascular surgery with the expectation that it will be able to grow and remain viable after implantation, no clinical study has evaluated the histological characteristics of implanted pedicled pericardium long after previous implantation. We describe herein histological findings of pedicled pericardium, which had been used for three years as an extracardiac conduit in Fontan pathway. A four-year-old boy with a history of Fontan operation using pedicled autologous pericardial roll required conduit replacement three years after the previous operation, and resected pericardial tissue was examined immunohistologically. Staining for CD34 revealed abundant microvasculature, suggesting preservation of viability. Staining for factor VIII demonstrated the presence of endothelium on the luminal surface of the conduit. Elastica-van Gieson staining revealed a band of elastic tissue, which is generally found not in the native pericardium but in the vascular wall structures. These findings suggested that the pedicled pericardium thus appeared to have remained viable and might have differentiated to resemble tissue of the vascular wall after having been used in Fontan pathway.

Child, Preschool↗
PubMed2006

Increased plasma monocyte chemoattractant protein-1 level in idiopathic pulmonary arterial hypertension.

OBJECTIVE: Monocyte chemoattractant protein-1 (MCP-1), a pro-inflammatory chemokine, has potent chemoattractant activity for monocytes/macrophages. We sought to investigate the clinical significance of MCP-1 in idiopathic pulmonary arterial hypertension (IPAH). METHODS: This study included 28 patients with IPAH, seven patients with pulmonary arterial hypertension (PAH) related to collagen vascular disease, and 13 healthy subjects. Plasma MCP-1 levels were measured together with serum IL-6 and tumour necrosis factor-alpha (TNF-alpha) levels. RESULTS: Circulating levels of MCP-1, IL-6 and TNF-alpha were significantly higher in patients with IPAH than in healthy controls, although they were lower than in patients with PAH related to collagen vascular disease. Plasma MCP-1 did not significantly correlate with any haemodynamic variables. However, plasma MCP-1 levels correlated negatively with the disease duration (time from symptom onset). CONCLUSIONS: Plasma MCP-1 levels were elevated in patients with IPAH, and this elevation was particularly marked in the early stage of disease. Taking into account the chemoattractant activity of MCP-1, these results imply a contribution of MCP-1 to the development of pulmonary hypertension.

Adolescent↗
PubMed2006

Valve repair with maze procedure in acromegaly.

Acromegaly is characterized by a hypersecretion of growth hormone and is frequently associated with valvular abnormality and arrhythmia. The increased morbidity and mortality is primarily caused by stroke and cardiovascular disease. Therefore, valve reconstruction and sinus rhythm recovery will be particularly beneficial. We report herein the successful surgical treatment of two patients with combined valvular insufficiency and chronic atrial fibrillation in the setting of acromegaly.

Acromegaly↗
PubMed2005

Surgical treatment of aortic regurgitation due to Takayasu arteritis: long-term morbidity and mortality.

BACKGROUND: The goal of this retrospective study was to determine the late outcome of surgical treatment for aortic valve regurgitation due to Takayasu arteritis and correlate it with evidence of inflammation on pathological examination. METHODS AND RESULTS: Ninety consecutive patients who underwent surgery for aortic valve regurgitation due to Takayasu arteritis between 1979 and 2003 were studied. Intraoperative pathological specimens of the aortic wall from 69 patients were retrospectively examined for inflammation. Aortic valve replacement was performed in 63 patients (group A) and composite graft repair in 27 patients (group B). The aortic root diameter was 39.9+/-9.5 mm in group A and 54.4+/-13.6 mm in group B (P<0.0001). Preoperative steroid therapy was performed in 40 patients (44.4%). Hospital mortality was 4.8% (3/63) in group A and 7.4% (2/27) in group B. The overall 15-year survival rate was 76.1%. Detachment of the valve or graft occurred in 11.1% (7/63) of group A and in 3.7% (1/27) of group B patients (P=0.43). Late dilatation (>50 mm) of the residual ascending aorta occurred in 11.1% (7/63) of group A and in 3.7% (1/27) of group B patients (P=0.43). Active inflammation was confirmed in intraoperative pathological specimens of 10 patients, and detachment of the valve or graft occurred in 4 of these patients. Univariate analysis of background variables revealed active inflammation to be a risk factor for detachment (P=0.0001; risk ratio 55). CONCLUSIONS: Late dilatation of the ascending aorta after aortic valve replacement is a clinically important finding. Active inflammation could be related to valve or graft detachment.

Adult↗
PubMed2005

Altered expression balance of matrix metalloproteinases and their inhibitors in human carotid plaque disruption: results of quantitative tissue analysis using real-time RT-PCR method.

BACKGROUND: The balance between degradation and synthesis of extracellular matrix determines its content in atherosclerotic tissue. To examine the role of expression balance of matrix metalloproteinases (MMPs) to their inhibitors, tissue inhibitors of metalloproteinases (TIMPs) and tissue factor pathway inhibitor-2 (TFPI-2) in the development and disruption of atherosclerotic plaque, these gene expressions in human carotid plaque were quantitatively determined by real-time reverse transcription (RT)-polymerase chain reaction (PCR) method. METHODS: Total RNA for cDNA synthesis was extracted from tissues in 24 patients with carotid endarterectomy. The amounts of cDNAs for MMP-1, -2, -3 and -9, TFPI-2 and TIMP-1, -2 and -3 were determined by real-time RT-PCR method, and normalized with glutaraldehyde 3-dehydrogenase. RESULTS: In plaques, the expression MMP-1 (1.53+/-0.25, mean+/-S.E.M.), MMP-3 (1.99+/-0.59) and MMP-9 (2.00+/-0.51) was augmented compared to those in the adjacent control regions (0.60+/-0.16, 0.46+/-0.18 and 0.58+/-0.21, respectively, p<0.05). The expression of TFPI-2 was lower in plaques (0.32+/-0.08) than in controls (0.94+/-0.23, p<0.01). Although the expression of TIMP-1 was higher in plaques (1.28+/-0.23) than in controls (0.81+/-0.10, p<0.05), the indices of MMP-1/TIMP-1, MMP-3/TIMP-3 and MMP-9/TIMP-1 were still significantly higher in plaques. Interestingly, MMP-9 and the resulting MMP-9/TIMP-1 balance in plaques with disruption were significantly higher (3.36+/-1.52 and 1.66+/-0.12, n=11) than those in non-disrupted plaques (1.11+/-0.52 and 0.76+/-0.12, n=13, p<0.05). CONCLUSION: With the decreased expression of TFPI-2, upregulation of MMPs in atherosclerotic plaque was disproportional to that of TIMPs, suggesting that imbalanced degradation and synthesis of extracellular matrix persists in advanced lesions, particularly in plaques with disruption.

Aged↗
PubMed2005

Adrenomedullin enhances angiogenic potency of bone marrow transplantation in a rat model of hindlimb ischemia.

BACKGROUND: Previous studies have shown that adrenomedullin (AM) inhibits vascular endothelial cell apoptosis and induces angiogenesis. We investigated whether AM enhances bone marrow cell-induced angiogenesis. METHODS AND RESULTS: Immediately after hindlimb ischemia was created, rats were randomized to receive AM infusion plus bone marrow-derived mononuclear cell (MNC) transplantation (AM+MNC group), AM infusion alone (AM group), MNC transplantation alone (MNC group), or vehicle infusion (control group). The laser Doppler perfusion index was significantly higher in the AM and MNC groups than in the control group (0.74+/-0.11 and 0.69+/-0.07 versus 0.59+/-0.07, respectively, P<0.01), which suggests the angiogenic potency of AM and MNC. Importantly, improvement in blood perfusion was marked in the AM+MNC group (0.84+/-0.08). Capillary density was highest in the AM+MNC group, followed by the AM and MNC groups. In vitro, AM inhibited MNC apoptosis, promoted MNC adhesiveness to a human umbilical vein endothelial cell monolayer, and increased the number of MNC-derived endothelial progenitor cells. In vivo, AM administration not only enhanced the differentiation of MNC into endothelial cells but also produced mature vessels that included smooth muscle cells. CONCLUSIONS: A combination of AM infusion and MNC transplantation caused significantly greater improvement in hindlimb ischemia than MNC transplantation alone. This effect may be mediated in part by the angiogenic potency of AM itself and the beneficial effects of AM on the survival, adhesion, and differentiation of transplanted MNCs.

Adrenomedullin↗
PubMed2005

Coronary embolism and subsequent myocardial abscess complicating ventricular aneurysm and tachycardia.

A 62-year-old female experienced a ventricular aneurysm and tachycardia caused by coronary embolism from mitral valve endocarditis. The patient underwent endoventricular patch plasty and cryoablation concomitant with valve replacement and survived without any operative complications. Pathological examination suggested that abscess formation played an important role regarding the disruption of the ventricular wall and development of the ventricular aneurysm and tachycardia. In previous reports, a myocardial abscess caused by a septic embolism has only been diagnosed using postmortem examinations as colony growth around the capillary vessels in the myocardium. We considered that our operation was effective and feasible in such an occurrence.

Abscess↗
PubMed2005

Elevation of plasma matrix metalloproteinase-9 in the culprit coronary artery in patients with acute myocardial infarction: clinical evidence from distal protection.

BACKGROUND: Although the elevation of circulating plasma matrix metalloproteinase (MMP)-9 levels in patients with acute myocardial infarction (AMI) has been documented, the origin of MMP-9 remains unclear. METHODS AND RESULTS: Plasma MMP-9 levels in both the peripheral circulation and coronary arteries were measured in patients with AMI (n=23) and with stable angina pectoris (SAP, n=10) during percutaneous coronary intervention (PCI) with a distal protection device. Blood samples were collected from the femoral artery (FA) and the coronary artery before (Initial) and after (Second) dilation of the culprit lesion. Coronary sinus blood samples were obtained immediately after PCI (n=7). Coronary artery plaque fragments were aspirated in patients with AMI (n=20) and compared with those from patients with SAP who underwent directional atherectomy (n=10). MMP-9 levels in Initial and Second were significantly higher in patients with AMI than in patients with SAP (p<0.01). In AMI patients MMP-9 levels were significantly higher in Initial than in the FA (p<0.05), and were further increased in Second (p<0.0001), whereas those in the coronary sinus were similar to the FA. Immunohistochemistry revealed augmented MMP-9 expression in the coronary artery plaque fragments from AMI patients. CONCLUSIONS: MMP-9 is mainly released into the coronary circulation from the coronary artery plaque in patients with AMI.

Acute Disease↗
PubMed2005

Sustained upregulation of inflammatory chemokine and its receptor in aneurysmal and occlusive atherosclerotic disease: results form tissue analysis with cDNA macroarray and real-time reverse transcriptional polymerase chain reaction methods.

BACKGROUND: Although cytokines are known to be pivotal in the development of atherosclerotic diseases, few data exist regarding their expressions in the established stages such as aneurysmal or occlusive lesions. Therefore, in the present study the gene expression levels of cytokine-related substances in abdominal aortic aneurysm (AAA) and carotid artery stenosis (CAS) were determined using cDNA macroarray and real-time reverse transcriptase polymerase chain reaction (RT-PCR) methods. METHODS AND RESULTS: Tissue samples were obtained from 31 patients with AAA and 24 with CAS. The array-specific [33P]-labeled cDNA probe mixture synthesized from 2.5 microg total RNA with gene-specific primers was hybridized with nylon membranes containing 375 cDNA clones. Densitometric analysis confirmed differences in expression (>5-fold) for 97 of the cytokine-related gene products between AAA and adjacent control tissue. Among these, simultaneous upregulation was found in the expression of interleukin (IL)-8 (9-fold) and its receptor, CXCR-2 (11-fold). Thus, the expressions of IL-8 and CXCR-2 were further quantified by real-time RT-PCR. The expression of both the genes was significantly upregulated in both AAA and CAS compared with control regions as followed: IL-8=0.53+/-0.16 vs 0.11+/-0.04 (p<0.01); CXCR-2=2.04+/-0.75 vs 0.29+/-0.10 (p<0.01) in AAA, and IL-8=1.35 +/-0.25 vs 0.60+/-0.16; CXCR-2=2.00 +/-0.51 vs 0.58+/-0.21 (p<0.05) in CAS. Under these conditions, the gene expressions of monocyte chemotactic protein-1 and its receptor, CCR-2, were not significantly different in the control and diseased regions of both AAA and CAS. CONCLUSIONS: Sustained upregulation of IL-8 and CXCR-2 was observed in both AAA and CAS, suggesting the inflammatory process is still active in established dilated and occlusive atherosclerotic diseases. Whether upregulation of this system could be protective or not protective for disease development requires further study.

Aged↗
PubMed2004

Adrenomedullin enhances therapeutic potency of bone marrow transplantation for myocardial infarction in rats.

Adrenomedullin (AM), a potent vasodilator, induces angiogenesis and inhibits cell apoptosis through the phosphatidylinositol 3-kinase/Akt pathway. Transplantation of bone marrow-derived mononuclear cells (MNC) induces angiogenesis. We investigated whether infusion of AM enhances the therapeutic potency of MNC transplantation in a rat model of myocardial infarction. Immediately after coronary ligation, bone marrow-derived MNC (5 x 10(6) cells) were injected into the ischemic myocardium, followed by subcutaneous administration of 0.05 microg x kg(-1) x min(-1) AM (AM-MNC group) or saline (MNC group) for 3 days. Another two groups of rats received subcutaneous administration of AM alone (AM group) or saline (control group). Hemodynamic and histological analyses were performed 4 wk after treatment. Cardiac infarct size was significantly smaller in the MNC and AM groups than in the control group. A combination of AM infusion and MNC transplantation demonstrated a further decrease in infarct size. Left ventricular (LV) maximum change in pressure over time and LV fractional shortening were significantly improved only in the AM-MNC group. AM significantly increased capillary density in ischemic myocardium, suggesting the angiogenic potency of AM. AM infusion plus MNC transplantation demonstrated a further increase in capillary density compared with AM or MNC alone. Although MNC apoptosis was frequently observed 72 h after transplantation, AM markedly decreased the number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells among the transplanted MNC. In conclusion, AM enhanced the angiogenic potency of MNC transplantation and improved cardiac function in rats with myocardial infarction. This beneficial effect may be mediated partly by the angiogenic property of AM itself and by its antiapoptotic effect on MNC.

Adrenomedullin↗
PubMed2004

C-type natriuretic peptide ameliorates monocrotaline-induced pulmonary hypertension in rats.

C-type natriuretic peptide (CNP) has been shown to act as a local regulator of vascular tone and remodeling. We investigated whether CNP ameliorates monocrotaline (MCT)-induced pulmonary hypertension in rats. Rats received a continuous infusion of CNP or placebo. Significant pulmonary hypertension developed 3 weeks after MCT. However, infusion of CNP significantly attenuated the development of pulmonary hypertension and vascular remodeling. Neither systemic arterial pressure nor heart rate was altered. Interestingly, CNP enhanced Ki-67 expression, a marker for cell proliferation, in pulmonary endothelial cells and augmented lung tissue content of endothelial nitric oxide synthase. CNP significantly suppressed apoptosis of pulmonary endothelial cells, decreased the number of monocytes/macrophages, and inhibited expression of plasminogen activator inhibitor type 1, a marker for fibrinolysis impairment, in the lung. In addition, CNP significantly increased the survival rate in MCT rats. Finally, infusion of CNP after the establishment of pulmonary hypertension also had beneficial effects on hemodynamics and survival. In conclusion, infusion of CNP ameliorated MCT-induced pulmonary hypertension and improved survival. These beneficial effects may be mediated by regeneration of pulmonary endothelium, inhibition of endothelial cell apoptosis, and prevention of monocyte/macrophage infiltration and fibrinolysis impairment.

Animals↗
PubMed2004

In situ measurements of crossbridge dynamics and lattice spacing in rat hearts by x-ray diffraction: sensitivity to regional ischemia.

BACKGROUND: Synchrotron radiation has been used to analyze crossbridge dynamics in isolated papillary muscle and excised perfused hearts with the use of x-ray diffraction techniques. We showed that these techniques can detect regional changes in rat left ventricle contractility and myosin lattice spacing in in situ ejecting hearts in real time. Furthermore, we examined the sensitivity of these indexes to regional ischemia. METHODS AND RESULTS: The left ventricular free wall of spontaneously beating rat hearts (heart rate, 290 to 404 bpm) was directly exposed to brief high-flux, low-emittance x-ray beams provided at SPring-8. Myosin mass transfer to actin filaments was determined as the decrease in reflection intensity ratio (intensity of 1,0 plane over the 1,1 plane) between end-diastole and end-systole. The distance between 1,0 reflections was converted to a lattice spacing between myosin filaments. We found that mass transfer (mean, 1.71+/-0.09 SEM, n=13 hearts) preceded significant increases in lattice spacing (2 to 5 nm) during systole in nonischemic pericardium. Left coronary occlusion eliminated increases in lattice spacing and severely reduced mass transfer (P<0.01) in the ischemic region. CONCLUSIONS: Our results suggest that x-ray diffraction techniques permit real-time in situ analysis of regional crossbridge dynamics at molecular and fiber levels that might also facilitate investigations of ventricular output regulation by the Frank-Starling mechanism.

Actin Cytoskeleton↗
PubMed2004

Adrenomedullin gene transfer induces therapeutic angiogenesis in a rabbit model of chronic hind limb ischemia: benefits of a novel nonviral vector, gelatin.

BACKGROUND: Earlier studies have shown that adrenomedullin (AM), a potent vasodilator peptide, has a variety of cardiovascular effects. However, whether AM has angiogenic potential remains unknown. This study investigated whether AM gene transfer induces therapeutic angiogenesis in chronic hind limb ischemia. METHODS AND RESULTS: Ischemia was induced in the hind limb of 21 Japanese White rabbits. Positively charged biodegradable gelatin was used to produce ionically linked DNA-gelatin complexes that could delay DNA degradation. Human AM DNA (naked AM group), AM DNA-gelatin complex (AM-gelatin group), or gelatin alone (control group) was injected into the ischemic thigh muscles. Four weeks after gene transfer, significant improvements in collateral formation and hind limb perfusion were observed in the naked AM group and AM-gelatin group compared with the control group (calf blood pressure ratio: 0.60+/-0.02, 0.72+/-0.03, 0.42+/-0.06, respectively). Interestingly, hind limb perfusion and capillary density of ischemic muscles were highest in the AM-gelatin group, which revealed the highest content of AM in the muscles among the three groups. As a result, necrosis of lower hind limb and thigh muscles was minimal in the AM-gelatin group. CONCLUSIONS: AM gene transfer induced therapeutic angiogenesis in a rabbit model of chronic hind limb ischemia. Furthermore, the use of biodegradable gelatin as a nonviral vector augmented AM expression and thereby enhanced the therapeutic effects of AM gene transfer. Thus, gelatin-mediated AM gene transfer may be a new therapeutic strategy for the treatment of peripheral vascular diseases.

Adrenomedullin↗
PubMed2004

Application of real-time RT-PCR to quantifying gene expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in human abdominal aortic aneurysm.

BACKGROUND: The relative expression levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), key regulators in remodeling of extracellular matrix, are considered to play a pivotal role in the development of abdominal aortic aneurysm (AAA). However, few data exist regarding quantitative assessment of their expression in clinical settings. METHODS: In 22 patients with AAA who underwent graft replacement, tissue samples of the AAA and non-dilated aorta were obtained. Using a real-time RT-PCR method that enabled quantitative measurement of mRNA levels in small tissue samples, we determined gene expression levels of MMPs and TIMPs relative to that of glutaraldehyde 3-phosphate dehydrogenase in each sample. RESULTS: The expression levels of the MMP-1 and -3 genes were significantly augmented in AAA compared with non-dilated regions (4.48 +/- 2.01 versus 0.26 +/- 0.12, P < 0.01 and 1.89 +/- 1.00 versus 5.01 +/- 0.97, P < 0.05, respectively). Although genes for TIMP-1, -2 and -3 tended to be upregulated in AAA, relative expression levels of MMP-1 to TIMP-1, MMP-1 to TIMP-2, MMP-1 to TIMP-3, and MMP-3 to TIMP-2 were still higher in AAA than in non-dilated regions (1.12 +/- 0.63 versus 0.10 +/- 0.03, 4.13 +/- 1.12 versus 0.43 +/- 0.11, 1.61 +/- 0.59 versus 0.14 +/- 0.03, and 7.81 +/- 1.60 versus 2.56 +/- 0.76, respectively, P < 0.05). CONCLUSION: These results demonstrate that the present real-time RT-PCR method is reliable for the determination of mRNA levels in small samples of vascular tissue and that disproportional expression of both MMP-1 and MMP-3 relative to TIMPs relates pathologically to the evolution of AAA.

Aged↗
PubMed2004

In vivo tissue-engineered small-caliber arterial graft prosthesis consisting of autologous tissue (biotube).

In this study, vascular-like tubular tissues called biotubes, consisting of autologous tissues, were prepared using in vivo tissue engineering. Their mechanical properties were evaluated for application as a small-caliber artificial vascular prosthesis. The biotubes were prepared by embedding six kinds of polymeric rods [poly(ethylene) (PE), poly(fluoroacetate) (PFA), poly(methyl methacrylate) (PMMA), segmented poly(urethane) (PU), poly(vinyl chloride) (PVC), and silicone (Si)] as a mold in six subcutaneous pouches in the dorsal skin of New Zealand White rabbits. For rods apart from PFA, biotubes were constructed after 1 month of implantation by encapsulation around the polymeric implants. The wall thickness of the biotubes ranged from about 50 to 200 microm depending on the implant material and were in the order PFA < PVC < PMMA < PU < PE. As for PE, PMMA, and PVC, the thickness increased after 3 months of implantation and ranged from 1.5-to 2-fold. None of the biotubes were ruptured when a hydrostatic pressure was gradually applied to their lumen up to 200 mmHg. The relationship between the intraluminal pressure and the external diameter, which was highly reproducible, showed a "J"-shaped curve similar to the native artery. The tissue mostly consisted of collagen-rich extracellular matrices and fibroblasts. Generally, the tissue was relatively firm and inelastic for Si and soft for PMMA. For PMMA, PE, and PVC the stiffness parameter (beta value; one of the indexes for compliance) of the biotubes obtained was similar to those of the human coronary, femoral, and carotid arteries, respectively. Biotubes, which possess the ability for wide adjustments in their matrices, mechanics, shape, and luminal surface design, can be applied for use as small-caliber blood vessels and are an ideal implant because they avoid immunological rejection.

Animals↗
PubMed2004

Immunological and histological evaluation of decellularized allograft in a pig model: comparison with cryopreserved allograft.

BACKGROUND AND AIM OF THE STUDY: The remodeling process of the decellularized allograft after implantation remains unclear. Herein, the hemodynamics, recellularization and immunological response of the decellularized allograft were evaluated at four weeks after implantation in a mini-pig model, and compared with a cryopreserved allograft. METHODS: Six porcine pulmonary allografts were harvested from mini-pigs, and cryopreserved for four weeks. In two pigs, the grafts were decellularized with Triton X solution, after which static reseeding of the valve surface was performed for 48 h with autologous endothelial cells harvested from a leg artery. Decellularization, but not reseeding, was carried out in two mini-pigs, and cryopreservation alone in two mini-pigs. Whilst under right heart bypass, the right ventricular outflow tract was replaced in six minipigs. The grafts were explanted after four weeks; analysis included direct pressure measurement, echocardiography, macroscopy, light microscopy with hematoxylin and eosin staining, and immunohistochemical studies to identify macrophages, T lymphocytes, and endothelial cells. RESULTS: Hemodynamically and macroscopically, there were no major differences between the three groups. In the cryopreservation-only group, immunohistochemistry showed an influx of macrophages, and T lymphocytes at the cusps. Endothelial cell coverage was found in the decellularized and decellularized + cell-seeded groups, but no macrophages and T lymphocytes were found at the cusps. CONCLUSION: Decellularization of the cryopreserved allograft may reduce the inflammatory response and improve its long-term durability.

Animals↗