Pharmacological cardiac organ protection during cardiopulmonary bypass presents an opportunity for improvement. A number of different strategies have been established to minimize ischemia/reperfusion-induced damage to the heart. Among these, cardioplegia with histidine-tryptophan-ketoglutarate solution and hypothermia are the most frequently used regimens. The antibiotic minocycline has been used in this context for neuroprotection. The aim of the current study was to evaluate whether the application of minocycline prior to cardioplegia exerts a protective effect on cardiac muscle. For this purpose, this study investigated six rabbit hearts with minocycline treatment (1 μmol/L) and six without in a Langendorff model of 90 min cold cardioplegic arrest using Custodiol followed by a 30 min recovery phase. Histological analysis of cardiac muscle revealed that markers of apoptosis, oxidative and nitrosative stress were significantly lower in the minocycline group, whereas adenosine triphosphate (ATP)- and malondialdehyde (MDA)-levels and O2-consumption were not affected by minocycline. Functionally, recovery of dP/dt (max) and dP/dt (min) was significantly faster in the minocycline group than in control. This leads to the conclusion that adding minocycline to the cardioplegic solution may improve left ventricular recovery after cardioplegic arrest involving reduced pro-apoptotic effects.
The SCBF changed significantly during extensive aortic arch surgery with circulatory arrest and moderate hypothermia, but such changes were comparable between the FET and cET groups. The implantation of hybrid stent graft did not influence SCBF in thoracic and lumbar segments of the spinal cord. The immunohistological examination showed no differences between cET and FET regarding ischaemic damage and hypoxia-induced effects in spinal cord segments.
BackgroundTranscatheter pulmonary valve replacement is currently performed in clinical trials, but is limited by the use of glutaraldehyde-treated bioprostheses. This feasibility study was performed to evaluate delivery-related tissue distortion during implantation of tissue-engineered (TE) heart valves.Material/MethodsThe injectable TE heart valve was mounted on a self-expanding nitinol stent (n=7) and delivered into the pulmonary position in 7 pigs, (weight 26 to 31 kg), performing a sternotomy or limited lateral thoracotomy. Prior to implantation, the injectable TE heart valves were crimped and inserted into an applicator. Positioning of the implants was guided by fluoroscopy, and after careful deployment, angiographic examination was performed to evaluate the correct delivered position. Hemodynamic measurements were performed by epicardial echocardiography. Finally, the animals were sacrificed and the injectable TE heart valves were inspected by gross examination and histological examination.ResultsOrthotopic deliveries of the injectable TE heart valves were all successful performed, expect in 1 where the valve migrated due to a discrepancy between pulmonary valve annulus size and injectable TE valve size. Angiographic evaluation (n=6) showed normal valve function, supported by epicardial echocardiography in which no increased flow velocity was measured, neither trans- nor paravalvular regurgitation. Histological evaluation demonstrated absence of tissue damage from the delivery process.ConclusionsTranscatheter implantation of an injectable TE heart valve seems to be possible without tissue distortion due to the delivery system.
BackgroundThe aims of this study were to compare the morphological, biochemical, and functional properties of reprogrammed bone marrow stem cell (BMSC)-derived arterial endothelial cells (AECs) and venous endothelial cells (VECs), following adenosine triphosphate (ATP)-stimulation in a mini pig animal model.Material/MethodsBone marrow aspiration was performed in six adult mini pigs. Harvested mononuclear cells were isolated, cultured, and treated with vascular endothelial growth factor (VEGF) (16 μg/ml). Transformed cells were characterized using immunofluorescence staining for CD31 and von Willebrandt factor (vWF) and expression of endothelial nitric oxide synthase (eNOS). Cell release of nitric oxide (cNO) was measured using spectrophotometry. Matrigel assays were used to investigate angiogenesis in transformed BMSCs.ResultsReprogrammed BMSCs in culture showed a typical cobblestone-like pattern of growth. Immunofluorescence staining was positive for CD31 and vWF expression. Expression of eNOS, using immunofluorescence staining and Western blot, showed no difference between the reprogrammed BMSCs and VECs. Spectrophotometric examination following stimulation with 10mmol/l ATP, showed comparable cNO release for reprogrammed BMSCs (10.87±1.76 pmol/106 cells/min) and VECs (13.23±2.16 pmol/106 cells/min), but reduced cNO release for AECS (3.44±0.75 pmol/106 cells/min). Matrigel assay for angiogenesis showed vascular tube formation of differentiated BMSC endothelial cells (grade 3.25). BMSCs cultured without VEGF did not demonstrate vascular tube formation.ConclusionsThe findings of this study showed that eNOS expression and release of NO could be used to show that BMSCs can be reprogrammed to functional VECs and AECs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.