| 1. |
- Methe, Ketaki, et al.
(författare)
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Differential Activation of Immune Cells for Genetically Different Decellularized Cardiac Tissues
- 2020
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Ingår i: Tissue Engineering Part A. - : Mary Ann Liebert Inc. - 1937-3341 .- 1937-335X. ; 26:21-22, s. 1180-1198
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Tidskriftsartikel (refereegranskat)abstract
- The immunogenicity of the extracellular matrix (ECM) from genetically similar (syngeneic) and dissimilar (allogeneic and xenogeneic) species has puzzled the scientific community for many years. After implantation, the literature describes an absorption of ECM material since it is biodegradable. However, no clear insight really exists to substantiate how the underlying immune and biological responses result in absorption of ECM materials. In this context, it is important to characterize infiltrating cells and identify dominant cell populations in the infiltrate. We have studied the immune response in mice after implantation of decellularized (DC) cardiac scaffolds derived from pig and mouse. The polymorphism of the infiltrate into the implanted material signifies the importance of the adaptive immune response that is distinct for xenoimplants and alloimplants. Matrix resorption takes place mainly through phagocytic cells such as mast cells, dendritic cells, and macrophages. Histochemical observations show that innate CD8(+)T cells develop immune tolerance, whereas proteomic analysis predicts the different T cell progenies for alloscaffolds and xenoscaffolds. The amalgamation of graft tolerance and involvement of both B and T cell populations in the vicinity of the graft could be decisive in wound remodeling and survival of the graft. This challenging area presents potential targets for the development of immune-privileged biomaterials, immune tolerant cells, and therapeutic agents in the future. Impact statement In this study, we have characterized the allogeneic and xenogeneic immune responses for decellularized (DC) cardiac scaffolds. We postulate that although the T cells are important players for immune tolerance of DC graft, the mechanism of their differentiation inside the host is donor specific. In this study, we have reported the distinct immune responses for syngeneic DC scaffolds than allogeneic and xenogeneic scaffolds. This distinct response provides the bases for the different immune responses reported for DC homografts in the literature. This study can provide the greater insight for modification of postimplant strategies to achieve host acceptance of donor extracellular matrix scaffolds.
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| 2. |
- Olausson, Michael, 1956, et al.
(författare)
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Long-term Transplant Function After Thrombolytic Treatment Ex Vivo of Donated Kidneys Retrieved 4 to 5 H After Circulatory Death
- 2022
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Ingår i: Transplantation. - : Ovid Technologies (Wolters Kluwer Health). - 0041-1337. ; 106:12, s. 2348-2359
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Tidskriftsartikel (refereegranskat)abstract
- Background. Using a novel thrombolytic technique, we present long-term transplant function, measured by creatinine and iohexol clearance, after utilizing kidneys from porcine donors with uncontrolled donation after circulatory deaths, with 4.5-5 h of warm ischemia. Methods. Pigs in the study group were subjected to simulated circulatory death. After 2 h, ice slush was inserted into the abdomen and 4.5 h after death, the kidneys were retrieved. Lys-plasminogen, antithrombin-III, and alteplase were injected through the renal arteries on the back table. Subsequent ex vivo perfusion was continued for 3 h at 15 degrees C, followed by 3 h with red blood cells at 32 degrees C, and then transplanted into pigs as an autologous graft as only renal support. Living-donor recipient pigs that did not receive ex vivo perfusion, and unilateral nephrectomized pigs served as the controls. Results. Pigs in the study group (n = 13), surviving 10 d or more were included, of which 7 survived for 3 mo. Four animals in the living-donor group (n = 6) and all 5 nephrectomized animals survived for 3 mo. Creatinine levels in the plasma and urine, neutrophil gelatinaseassociated lipocalin levels, Kidney Injury Marker-1 expression, and iohexol clearance at 3 mo did not differ significantly between the study and living-donor groups. Histology and transmission electron microscopy after 3 mo showed negligible fibrosis and no other damage. Conclusions. The present method salvages kidneys from extended unontrolled donation after circulatory death using thrombolytic treatment while preserving histology and enabling transplantation after ex vivo reconditioning, with clinically acceptable late function after 3 mo, as measured by creatinine and iohexol clearance.
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| 3. |
- Olausson, Michael, 1956, et al.
(författare)
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Novel Ex-Vivo Thrombolytic Reconditioning of Kidneys Retrieved 4 to 5 Hours After Circulatory Death
- 2022
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Ingår i: Transplantation. - : Ovid Technologies (Wolters Kluwer Health). - 0041-1337. ; 106:8, s. 1577-1588
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Tidskriftsartikel (refereegranskat)abstract
- Background. Due to organ shortage, many patients do not receive donor organs. The present novel thrombolytic technique utilizes organs from donors with uncontrolled donation after circulatory deaths (uDCD), with up to 4-5h warm ischemia, without advanced cardiopulmonary resuscitation (aCPR) or extracorporeal circulation (EC) after death. Methods. The study group of pigs (n = 21) underwent simulated circulatory death. After 2h, an ice slush was inserted into the abdomen. Kidneys were retrieved 4.5h after death. Lys-plasminogen, antithrombin-III (ATIII), and alteplase (tPA) were injected through the renal arteries on the back table. Subsequent ex vivo perfusion at 15 degrees C was continued for 3h, followed by 3h with red blood cells (RBCs) at 32 degrees C. Perfusion outcome and histology were compared between uDCD kidneys, receiving no thrombolytic treatment (n = 8), and live donor kidneys (n = 7). The study kidneys were then transplanted into pigs as autologous grafts with a single functioning autologous kidney as the only renal support. uDCD control pigs (n = 8), receiving no ex vivo perfusion, served as controls. Results. Vascular resistance decreased to <200 mmHg/mL/min (P < 0.0023) and arterial flow increased to >100mL/100g/min (P < 0.00019) compared to controls. In total 13/21 study pigs survived for >10 days, while all uDCD control pigs died. Histology was preserved after reconditioning, and the creatinine level after 10 days was next to normal. Conclusions. Kidneys from extended uDCD, not receiving aCPR/EC, can be salvaged using thrombolytic treatment to remove fibrin thrombi while preserving histology and enabling transplantation with a clinically acceptable early function.
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